Macleaya cordata lactone A and B and methods of making the same

Abstract

The application discloses Mao-calelloside A and B and a preparation method thereof, and belongs to the technical field of natural product organic synthesis and the technical field of medicines. The application provides Mao-calelloside A and Mao-calelloside B which are novel five-ring enanti-kaurene diterpene compounds and a preparation method thereof. The compound is synthesized for the first time, the synthesis route is novel, the synthesis method can provide an effective means for structural optimization based on ombuoside, and has important research value and application prospect.

Description

Technical Field

[0001] This invention belongs to the fields of natural product organic synthesis technology and pharmaceutical technology, specifically relating to a novel enantio-kauridine diterpenoid compound, trichomeoside A and trichomeoside B, a pharmaceutical composition and a method for its preparation. Background Technology

[0002] Natural product skeletons provide valuable templates for medicinal chemistry research on active molecules. For example, natural spirocyclic lactones and enantiocarbazine-type diterpenes have provided insights for the structural modification of oridonin. Trichoderma lactone A, discovered from *Isodon eriocalyx*, possesses a novel 1,10-secreting-2,20-cyclized-1,20-lactoneized-enantiocarbazine skeleton. However, due to the limited sample size of trichoderma lactone A, its absolute configuration and bioactivity studies cannot be determined. This invention aims to obtain trichoderma lactone A through semi-synthetic methods, addressing both the absolute configuration and sample quantity issues, while also providing a new structural modification method for oridonin, leading to the synthesis of the structurally modified precursor molecule trichoderma lactone B based on oridonin.

[0003] Currently, there are no reports in the existing technology regarding the preparation methods of trichomealin A and trichomealin B. Summary of the Invention

[0004] The purpose of this invention is to provide novel enantio-kaurane diterpenoid compounds, trichomedin A and trichomedin B, pharmaceutical compositions using these compounds as active ingredients, and methods for their preparation. This invention utilizes an intramolecular Wolf rearrangement tandem lactonization reaction to construct a key novel framework, enabling the preparation of trichomedin A and trichomedin B. This has significant methodological importance, research value, and application prospects.

[0005] To achieve the above-mentioned objectives of the present invention, the present invention provides the following specific solutions:

[0006] The following structural formulas illustrate a novel enantio-kaurane-type diterpenoid compound, pilocarpine A, and a novel structurally modified precursor compound, pilocarpine B.

[0007]

[0008]

[0009] This invention also provides a method for preparing the novel enantio-kaurane diterpenoid compound pilocarpine A. The method uses pilocarpine A as the starting material and first obtains intermediate E through a four-step reaction. Intermediate E is then converted into a key intermediate through a crucial intramolecular Wolf rearrangement tandem lactonization reaction (5). Finally, pilocarpine A is obtained through a five-step reaction. The simplified process is as follows:

[0010]

[0011] The preparation method of the aforementioned pilocarpine lactone A is as follows:

[0012]

[0013] The method for preparing pilocarpine lactone A, as described above, includes the following steps:

[0014] (1) Preparation of intermediate B: Compound A (0.01–100 g) was dissolved in (1–100 mL) dichloromethane, and diisopropylethylamine (1–100 mL) was added. SEM-Cl (1–100 mL) was slowly added dropwise under an ice bath at 0 °C. The reaction was then carried out at room temperature for 4 hours. After the reaction was confirmed to be complete by TLC, the reaction was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate B by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0015]

[0016] (2) Preparation of intermediate C: Intermediate B was dissolved in tetrahydrofuran (1–100 mL) and cooled completely in a cryogenic reactor at -50°C for 15 minutes. Then, NaBH4 (1–15 g) was slowly added, and the reaction was allowed to proceed for 30 minutes. After the reaction was confirmed to be complete by TLC, the mixture was quenched with acetone, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate B by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0017]

[0018] (3) Preparation of intermediate D: Dissolve the prepared C in (1-100 mL) of methanol, add nickel dichloride hexahydrate and stir thoroughly for half an hour; then place in a low-temperature reactor at -78°C and cool thoroughly for half an hour. Add NaBH4 (1-15 g) slowly in three portions. The reaction solution turns black immediately after addition. After reacting thoroughly for 1 hour, move the reaction to room temperature and continue reacting for another hour. After the reaction is complete as detected by TLC, quench with saturated NaHCO3. After quenching, add (1-100 g) of diatomaceous earth, stir evenly, and filter with EtOAc. After filtration, extract with water, wash with saturated brine (50 mL), dry with anhydrous MgSO4, filter, concentrate and purify by column chromatography to obtain an amorphous solid compound. The compound is identified as intermediate D by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0019]

[0020] (4) Preparation of intermediate E: Intermediate D was dissolved in acetonitrile (1-100 mL), and DBU (1-20 mL) and p-methylbenzenesulfonyl chloride azide (1-20 mL) were added sequentially. The reaction was allowed to proceed at room temperature for 2 hours. After the reaction was confirmed to be complete by TLC, the mixture was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate E by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0021]

[0022] (5) Preparation of intermediate F: Compound E was dissolved in (1-10 mL) toluene and placed at 110 °C with stirring to react fully for two hours. After the reaction was complete as detected by TLC, the reaction was moved to room temperature and cooled. After cooling, the mixture was concentrated under reduced pressure and purified by column chromatography to obtain an amorphous white solid compound. The compound was identified as intermediate F by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0023]

[0024] (6) Preparation of intermediate G: Compound F was dissolved in (1-10 mL) dichloromethane, and the reaction was carried out at room temperature. DHP (1-10 mL) and p-toluenesulfonic acid pyridine salt (0.5-5 g) were added sequentially. The reaction was allowed to proceed at room temperature for 15 minutes. After the reaction was confirmed to be complete by TLC, the mixture was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an oily compound. The compound was identified as intermediate G by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0025]

[0026] (7) Preparation of intermediate H: Compound G was dissolved in tetrahydrofuran (1-10 mL). The reaction was carried out in a cryogenic reactor at -40°C and cooled for 10 minutes. LDA (1-10 mL) was added and reacted with the substrate for 40 minutes. Then oxaziridine (1-10 g) was added and the reaction was continued at -40°C for 2 hours. After the reaction was detected to be complete by TLC, the reaction was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an oily compound. The compound was identified as intermediate H by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0027]

[0028] (8) Preparation of intermediate I: Compound H was dissolved in ethanol (1-10 mL), and pyridine p-toluenesulfonic acid salt (0.1-5 g) was added. The mixture was reacted at 68 °C for 1 hour. The reaction was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an oily compound. The compound was identified as intermediate I by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0029]

[0030] (9) Preparation of intermediate J: Compound I was dissolved in (1-10 mL) dichloromethane, and acetic anhydride (0.1-1 mL) and DMAP (0.1-1 g) were added sequentially under ice bath conditions, and the reaction was carried out for 1 hour. The mixture was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate J by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0031]

[0032] (10) Preparation of pilocarpine lactone A: Compound J was dissolved in 1 mL of tetrahydrofuran, and trifluoroacetic acid (0.1-1 mL) was added under heating at 50 °C and reacted for 1 hour. The mixture was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as the target compound pilocarpine lactone A by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0033]

[0034] The intramolecular Wolf rearrangement tandem lactone reaction (5) step described in the process includes the following conditions:

[0035]

[0036] Note: a lsolated yield after flash chromatography; b Abbreviations: blueLED, blue light emitting diode; HPSL, high pressure sodium lamp; HPML, highpressure mercury lamp.

[0037] The intramolecular Wolf rearrangement tandem lactone reaction (5) is used for the preparation of novel oridonin derivatives. The procedure is as follows:

[0038]

[0039] A method for preparing pilocarpine lactone B, comprising the following steps:

[0040] (1) Preparation of intermediate L: Compound K was dissolved in acetone (1-100 mL), and Jones reagent (10 mL) was added under ice bath conditions at 0 °C and reacted for 15 minutes. After the reaction was detected by TLC, it was quenched with isopropanol, diluted with water and extracted with EtOAc, washed with saturated brine, dried with anhydrous MgSO4, filtered, concentrated and purified by column chromatography to obtain amorphous solid compound L. The compound was identified as intermediate L by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0041]

[0042] (2) Preparation of intermediate M: Compound L was dissolved in 1,2-dichloroethane (1-100 mL), and NaBH(OAc)3 (1-50 g) was added under ice bath conditions at 0 °C. Then, acetic acid (0.1-1 mL) was slowly added dropwise and reacted for 10 minutes. After the reaction was detected by TLC to be complete, the reaction was quenched with acetone, diluted with water, extracted with EtOAc, washed with saturated brine, dried with anhydrous MgSO4, filtered, concentrated and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate M by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0043]

[0044] (3) Preparation of intermediate N: Compound M was dissolved in dichloromethane (1-100 mL), and DIPEA (1-50 mL) and TMSCl (1-50 mL) were added sequentially under ice bath conditions at 0 °C. After reacting for 30 minutes under ice bath conditions, the mixture was concentrated under reduced pressure. The concentrated product was dissolved in acetonitrile, and DBU (1-50 mL) and p-toluenesulfonyl azide (1-50 mL) were added sequentially. After reacting for 2 hours, TBAF (1-50 g) was added dropwise and reacted for 30 minutes. After the reaction was detected to be complete by TLC, the mixture was diluted with water, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate N by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0045]

[0046] (4) Preparation of intermediate O: Compound N was dissolved in (1-100 mL) of dichloromethane. NaHCO3 (1-10 g) and Dess-Martin reagent (1-10 g) were added sequentially under ice bath conditions at 0 °C. The reaction was carried out for 10 minutes under ice bath conditions. After the reaction was detected by TLC, it was quenched with Na2O3S2, diluted with water, extracted with EtOAc, washed with saturated brine, dried with anhydrous MgSO4, filtered, concentrated and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate O by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0047]

[0048] (5) Preparation of pilocarpine lactone B: Compound O was dissolved in (1-50 mL) toluene and heated at 110 °C with stirring for two hours. After the reaction was complete as detected by TLC, the reaction was moved to room temperature and cooled. The mixture was then concentrated under reduced pressure and purified by column chromatography to obtain an amorphous white solid compound. The compound was identified as pilocarpine lactone B by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0049]

[0050] The use of pilocarpine A and / or pilocarpine B in the preparation of antitumor drugs, specifically in the preparation of drugs for cervical cancer, breast cancer, and colon cancer.

[0051] A pharmaceutical composition comprising the novel skeleton-type compounds trichomedin A and trichomedin B, and at least one pharmaceutically acceptable carrier.

[0052] Application of pharmaceutical compositions in the preparation of drugs for treating cervical cancer, breast cancer, and colon cancer.

[0053] The novel enantio-kaurane diterpenoid compounds, trichomedin A and trichomedin B, of this invention can be used directly or in combination as pharmaceuticals. The pharmaceutical composition contains 0.1% to 99%, preferably 0.5% to 90%, of the compounds of this invention, with the remainder being pharmaceutically acceptable, non-toxic, and inert pharmaceutically viable carriers or excipients for humans and animals.

[0054] The pharmaceutically acceptable carrier is one or more selected from solid, semi-solid, and liquid diluents, superfillers, and pharmaceutical excipients. The effective extract or effective fraction is administered in a dose per unit body weight. The drug of this invention can be administered orally and via oral spray.

[0055] It can be taken orally in solid or liquid formulations, such as powders, tablets, sugar-coated tablets, capsules, tinctures, syrups, and pills.

[0056] Oral sprays are available in solid or liquid formulations.

[0057] Compared with the prior art, the present invention has the following advantages:

[0058] This invention discloses the novel enantio-kaurane diterpenoid compound maoelactone A, which is synthesized for the first time. Its absolute and relative configurations were determined by nuclear magnetic resonance, mass spectrometry, circular dichroism (CD), and X-ray single-crystal diffraction. It is named maoelactone A. It can be prepared using the method of this invention. The structurally modified precursor maoelactone B is constructed from oridonin via a Wolf rearrangement tandem lactonization reaction. This invention represents the first synthesis of the novel enantio-kaurane diterpenoid compound and its synthetic intermediates, featuring a novel synthetic route and promising application prospects. Attached Figure Description

[0059] Figure 1 This is a flowchart of the synthetic route for a novel enantio-kauridine diterpenoid compound, trichomeoside A.

[0060] Figure 2 This is a flowchart of the synthetic route for pilocarpine lactone B.

[0061] Figure 3 This is a schematic diagram of the structures of compounds trichomeoside A and trichomeoside B. Detailed implementation method:

[0062] The present invention will be further described below with reference to the accompanying drawings, but this is not intended to limit the invention in any way. Any modifications or improvements made based on the teachings of this invention fall within the protection scope of this invention.

[0063] Example 1

[0064] The novel enantio-kaurane diterpenoid compound prepared in this invention is maoelactone A, isolated from medicinal plants. Maoelactone A was chemically synthesized from maoelactone A via a chemical reaction using maoelactone A as the starting material. Furthermore, the structurally modified precursor maoelactone B was constructed from oridonin via a Wolf rearrangement tandem lactonization reaction. The structural formulas of the above compounds are as follows:

[0065]

[0066] The preparation method of the novel enantio-kauridine diterpenoid compound pilocarpine A and its structurally modified precursor pilocarpine B of the present invention is as follows:

[0067] (1) Preparation of intermediate B: Compound A (0.01–100 g) was dissolved in (1–100 mL) dichloromethane, and diisopropylethylamine (1–100 mL) was added. SEM-Cl (1–100 mL) was slowly added dropwise under an ice bath at 0 °C. The reaction was then carried out at room temperature for 4 hours. After the reaction was confirmed to be complete by TLC, the reaction was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate B by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0068]

[0069] (2) Preparation of intermediate C: Dissolve the prepared B in tetrahydrofuran (1-100 mL) and cool it thoroughly in a cryogenic reactor at -50°C for 15 minutes. Then slowly add NaBH4 (1-15 g) and react thoroughly for 30 minutes. After the reaction is complete as detected by TLC, quench with acetone, extract with EtOAc, wash with saturated brine, dry with anhydrous MgSO4, filter, concentrate, and purify by column chromatography to obtain an amorphous solid compound. The compound is identified as intermediate B by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0070]

[0071] (3) Preparation of intermediate D: Dissolve the C prepared above in (1-100 mL) methanol, add nickel dichloride hexahydrate and stir thoroughly for half an hour; then place in a low-temperature reactor at -78℃ and cool thoroughly for half an hour. Add NaBH4 (1-15 g) slowly in three portions. The reaction solution turns black immediately after addition. After reacting thoroughly for 1 hour, move the reaction to room temperature and continue reacting for 1 hour. After the reaction is complete as detected by TLC, quench with saturated NaHCO3. After quenching, add (1-100 g) diatomaceous earth, stir evenly, and filter with EtOAc. After filtration, extract with water, wash with saturated brine (50 mL), dry with anhydrous MgSO4, filter, concentrate and purify by column chromatography to obtain an amorphous solid compound. The compound is identified as intermediate D by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0072]

[0073] (4) Preparation of intermediate E: Compound D was dissolved in acetonitrile (1–100 mL), and DBU (1–20 mL) and p-methylbenzenesulfonyl chloride azide (1–20 mL) were added sequentially. The reaction was allowed to proceed at room temperature for 2 hours. After the reaction was confirmed to be complete by TLC, the mixture was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate E by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0074]

[0075] (5) Preparation of intermediate F: Compound E was dissolved in (1-10 mL) toluene and placed at 110 °C with stirring to react fully for two hours. After the reaction was complete as detected by TLC, the reaction was moved to room temperature and cooled. After cooling, the mixture was concentrated under reduced pressure and purified by column chromatography to obtain an amorphous white solid compound. The compound was identified as intermediate F by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0076]

[0077] (6) Preparation of intermediate G: Compound F was dissolved in (1-10 mL) dichloromethane, and the reaction was carried out at room temperature. DHP (1-10 mL) and p-toluenesulfonic acid pyridine salt (0.5-5 g) were added sequentially. The reaction was allowed to proceed at room temperature for 15 minutes. After the reaction was confirmed to be complete by TLC, the mixture was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an oily compound. The compound was identified as intermediate G by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0078]

[0079] (7) Preparation of intermediate H: Compound G was dissolved in tetrahydrofuran (1-10 mL). The reaction was carried out in a cryogenic reactor at -40°C and cooled for 10 minutes. LDA (1-10 mL) was added and reacted with the substrate for 40 minutes. Then oxaziridine (1-10 g) was added and the reaction was continued at -40°C for 2 hours. After the reaction was detected to be complete by TLC, the reaction was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an oily compound. The compound was identified as intermediate H by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0080]

[0081] (8) Preparation of intermediate I: Compound H was dissolved in ethanol (1-10 mL), and pyridine p-toluenesulfonic acid salt (0.1-5 g) was added. The mixture was reacted at 68 °C for 1 hour. The reaction was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an oily compound. The compound was identified as intermediate I by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0082]

[0083] (9) Preparation of intermediate J: Compound I was dissolved in (1-10 mL) dichloromethane, and acetic anhydride (0.1-1 mL) and DMAP (0.1-1 g) were added sequentially under ice bath conditions, and the reaction was carried out for 1 hour. The mixture was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate J by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0084]

[0085] (10) Preparation of pilocarpine lactone A: Compound J was dissolved in 1 mL of tetrahydrofuran, and trifluoroacetic acid (0.1-1 mL) was added under heating at 50 °C and reacted for 1 hour. The mixture was quenched with saturated NaHCO3, extracted with EtOAc, washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as the target compound pilocarpine lactone A by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0086]

[0087] (11) Preparation of intermediate L: Compound K was dissolved in acetone (1-100 mL), and Jones reagent (10 mL) was added under ice bath conditions at 0 °C and reacted for 15 minutes. After the reaction was detected by TLC, it was quenched with isopropanol, diluted with water and extracted with EtOAc, washed with saturated brine, dried with anhydrous MgSO4, filtered, concentrated and purified by column chromatography to obtain amorphous solid compound L. The compound was identified as intermediate L by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0088]

[0089] (12) Preparation of intermediate M: Compound L was dissolved in 1,2-dichloroethane (1-100 mL), and NaBH(OAc)3 (1-50 g) was added under ice bath conditions at 0 °C. Then, acetic acid (0.1-1 mL) was slowly added dropwise and reacted for 10 minutes. After the reaction was detected by TLC to be complete, the reaction was quenched with acetone, diluted with water, extracted with EtOAc, washed with saturated brine, dried with anhydrous MgSO4, filtered, concentrated and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate M by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0090]

[0091] (13) Preparation of intermediate N: Compound M was dissolved in dichloromethane (1-100 mL), and DIPEA (1-50 mL) and TMSCl (1-50 mL) were added sequentially under ice bath conditions at 0 °C. After reacting for 30 minutes under ice bath conditions, the mixture was concentrated under reduced pressure. The concentrated product was dissolved in acetonitrile, and DBU (1-50 mL) and p-toluenesulfonyl azide (1-50 mL) were added sequentially. After reacting for 2 hours, TBAF (1-50 g) was added dropwise and reacted for 30 minutes. After the reaction was detected to be complete by TLC, the mixture was diluted with water, extracted with EtOAc, washed with saturated brine, dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate N by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0092]

[0093] (14) Preparation of intermediate O: Compound N was dissolved in (1-100 mL) of dichloromethane. NaHCO3 (1-10 g) and Des Martin reagent (1-10 g) were added sequentially under ice bath conditions at 0 °C. The reaction was carried out for 10 minutes under ice bath conditions. After the reaction was detected by TLC, it was quenched with Na2O3S2, diluted with water, extracted with EtOAc, washed with saturated brine, dried with anhydrous MgSO4, filtered, concentrated and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate O by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0094]

[0095] (15) Preparation of pilocarpine lactone B: Compound O was dissolved in (1-50 mL) toluene and heated and stirred at 110 °C for two hours. After the reaction was complete as detected by TLC, the reaction was moved to room temperature and cooled. The mixture was then concentrated under reduced pressure and purified by column chromatography to obtain an amorphous white solid compound. The compound was identified as pilocarpine lactone B by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance.

[0096]

[0097] Example 2

[0098] (1) Preparation of intermediate B: Compound A (20.0 g, 58 mmol, 1.0 equiv) was dissolved in 30 mL of dichloromethane, and diisopropylethylamine (11.5 mL, 87 mmol, 1.5 equiv) was added. SEM-Cl (15.0 mL, 87 mmol, 1.5 equiv) was slowly added dropwise under an ice bath at 0 °C. The reaction was then allowed to proceed at room temperature for 4 hours. After the reaction was confirmed to be complete by TLC, the mixture was quenched with saturated NaHCO3 (30 mL), extracted with EtOAc (3 × 300 mL), washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with petroleum ether / ethyl acetate as the eluent at a ratio of 12:1 to obtain amorphous solid compound B. f =0.41(silica,petroleum ether / acetone 4:1); (MeOH, c 0.07); 1H NMR (600MHz, CDCl3) δ=6.71(d,J=10.1,1H),6.29(s,1H),5.86(d,J=10.1,1H),5.82(s,1H),5.25(d,J=1.4,1H),5.02(d,J= 7.1,1H),4.77(d,J=7.1,1H),4.34(dd,J=10.3,1.3,1H),4.07(ddd,J=12.6,9.3,4.9,1H),4.00–3.93(m,2H),3.54(ddd,J= 12.0,9.3,5.8,1H),3.00(dd,J=9.8,4.5,1H),2.41(d,J=9.1,1H),2.34–2.25(m,2H),2.18(d,J=19.1,2H),2.12–2.02(m,1 H),1.97–1.92(m,1H),1.40–1.30(m,2H),1.23(d,J=17.0,6H),0.96(td,J=13.0,5.8,1H),0.89–0.80(m,1H),-0.02(s,9H); 13 C NMR(151MHz, CDCl3)δ=203.1,197.3,160.8,153.5,127.5,115.2,97.6,95.4,86.1,67.3,65.4,58 .4,54.7,47.9,47.1,36.1,33.9,30.4,29.6,25.9,25.6,19.2,17.9,–1.4; HRESIMS(m / z):[M+Na] + calcd forC 26 H 38 O6SiNa + 497.2330, found 497.2335.

[0099] (2) Preparation of intermediate C: Compound B (18.0 g, 38 mmol, 1.0 equiv) was dissolved in 20 mL of tetrahydrofuran and cooled completely in a cryogenic reactor at -50 °C for 15 minutes. Then, NaBH4 (2.8 g, 76 mmol, 2.0 equiv) was slowly added, and the reaction was allowed to proceed for 30 minutes. After the reaction was confirmed to be complete by TLC, the mixture was quenched with acetone, extracted with EtOAc (3 × 400 mL), washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with an eluent of petroleum ether / ethyl acetate = 85:15, yielding an amorphous solid compound C. f =0.32(silica,petroleum ether / acetone 4:1); (MeOH,c 0.04);mp 218–222℃, 1 H NMR(600MHz,CDCl3)δ=6.67(d,J=10.1,1H),5.87(d,J=10.1,1H),5.10(s,1H),5.10(s,1H),5.07(d,J=1.4,1H),4.96(d,J=6.9,1H),4.83(d,J=6.9,1H),4.38(d,J=2.7,1H),4.35(d,J=10.0,1H),4.15(d,J=2.6,1H),3.92–3.88(m,2H),3.85(ddd,J=11.4,9.5,5.5,1H),3.62(ddd,J=11.3,9.4,6.1,1H),2.62(dd,J=8.9,5.1,1H),2.48(d,J=7.9,1H),2.35–2.27(m,1H),2.01(s,1H),1.88–1.82(m,1H),1.80(d,J=12.2,1H),1.65(dd,J=12.3,5.1,1H),1.38(td,J=12.4,7.4,1H),1.30–1.24(m,1H),1.22(s,3H),1.16(s,3H),1.07–0.96(m,1H),0.03(s,9H); 13 C NMR(151MHz,CDCl3)δ=198.0,159.5,159.4,128.0,108.4,97.1,95.7,84.7,74.6,67.7,65.1,54.3,52.7,46.6,40.8,36.0,35.5,32.5,31.1,25.4,25.0,18.1,17.6,–1.4;HRESIMS(m / z):[M+Na] + calcd for C 26 H 40 O6SiNa + 499.2486,found 499.2475.

[0100] (3) Preparation of intermediate D: Compound C (10.0 g, 21 mmol, 1.0 equiv) was dissolved in 10 mL of methanol. Nickel dichloride hexahydrate was added and stirred thoroughly for half an hour. Then, the mixture was placed in a low-temperature reactor at -78 °C and cooled thoroughly for half an hour. NaBH4 (7.7 g, 210 mmol, 10.0 equiv) was slowly added in three portions. The reaction solution immediately turned black after the addition. After reacting thoroughly for 1 hour, the reaction was moved to room temperature and the reaction was continued for another hour. After the reaction was confirmed to be complete by TLC, saturated NaHCO3 (30 mL) was added to quench the reaction. After quenching, 40 g of diatomaceous earth was added and stirred evenly. The mixture was then filtered using EtOAc (3 × 400 mL). After filtration, water was added for extraction, followed by washing with saturated brine (50 mL), drying with anhydrous MgSO4, filtration, concentration, and purification by column chromatography. The eluent was petroleum ether / ethyl acetate = 85:15, yielding an amorphous solid compound D. f =0.38(silica,petroleum ether / acetone4:1); (MeOH, c 0.04); 1 H NMR (600MHz, CDCl3) δ=5.25(d,J=2.1,1H),5.14(s,1H),5.12–5.10(m,1H),4.91(d,J=7.0,1H),4.78(d,J=7.1,1H),4.39(d,J=2.8,1H),4 .34(d,J=10.4,1H),4.16(t,J=1.8,1H),3.89–3.79(m,2H),3.72(d,J=7.9,1H),3.60(ddd,J=11.5,9.5,6.1,1H),2.68–2.59(m,2H),2.44 (d,J=8.0,1H),2.39(dd,J=13.4,5.7,1H),2.24(ddd,J=14.9,9.1,2.9,1H),2.12(dd,J=13.4,8.8,1H),1.95–1.88(m,1H),1.72(d,J=12. 3,1H),1.67(m,2H),1.64(m,2H),1.40(td,J=12.4,7.7,1H),1.06–1. 00(m,1H),0.98(s,3H),0.96(s,3H),0.96–0.92(m,1H),0.02(s,9H); 13C NMR (151MHz, CDCl3) δ = 213.6, 159.3, 108.7, 97.1, 95.6, 85.4, 74.7, 67.6, 64.4, 57.1, 52.3, 49. 0,40.8,38.1,35.5,35.5,33.0,32.3,30.1,25.4,24.1,18.0,17.3,–1.4; HRESIMS(m / z):[M+Na] + calcdfor C 26 H 42 O6SiNa + 501.2643, found 501.2637.

[0101] (4) Preparation of intermediate E: Compound D (7.0 g, 15 mmol, 1.0 equiv) was dissolved in 7 mL of acetonitrile, and DBU (6.6 mL, 44 mmol, 3.0 equiv) and p-toluenesulfonyl chloride azide (5.8 mL, 75% in EA, 22 mmol, 1.5 equiv) were added sequentially. The reaction was allowed to proceed at room temperature for 2 hours. After the reaction was confirmed to be complete by TLC, it was quenched with saturated NaHCO3 (30 mL), extracted with EtOAc (3 × 300 mL), washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with eluent: petroleum ether / ethyl acetate = 6:1, to give an amorphous yellow solid compound E. f =0.38(silica,petroleum ether / acetone 3:1); (MeOH, c 0.05); mp 218–222°C; 1H NMR(600MHz, CDCl3)δ=5.17(d,J=1.5,1H),5.11–5.09(s,1H),5.09(s,1H),4.92(d,J=7.1,1H),4.80(d,J=6.9,1H),4.38–4.31(m,2H) ,4.10(dd,J=2.7,1.2,1H),3.89(dd,J=9.9,1.9,1H),3.87–3.81(m,1H),3.70(d,J=8.0,1H),3.60(ddd,J=11.8,9.3,6.2,1H),2.78(d, J=13.9,1H),2.61(dd,J=8.8,5.1,1H),2.29(dd,J=13.4,4.7,1H),2.24(d,J=13.9,1H),2.18–2.15(m,2H),1.88–1.83(m,1H),1.79(d ,J=12.3,1H),1.63(dd,J=12.3,5.1,1H),1.36(dt,J=11.2,6.5,2H),1.13(s,3H),1.07(s,3H),1.04–0.94(m,2H),0.02(d,J=1.1,9H); 13 C NMR (151MHz, CDCl3) δ = 192.5, 159.6, 108.4, 97.2, 95.4, 85.2, 74.7, 67.7, 65.1, 63.9, 56.0, 52. 7,47.1,41.4,37.9,35.4,33.6,32.6,29.2,25.4,21.3,18.1,17.8,–1.4; HRESIMS(m / z):[M+Na] + calcd for C 26 H 40 N2O6SiNa + 527.2548, found 527.2542.

[0102] (5) Preparation of intermediate F: Compound E (4.0 g, 10 mmol) was dissolved in 4 mL of toluene and reacted at 110 °C with stirring for two hours. After the reaction was complete as detected by TLC, the reaction mixture was moved to room temperature and cooled. The mixture was then concentrated under reduced pressure and purified by column chromatography with petroleum ether / ethyl acetate as the eluent (6:1) to obtain an amorphous white solid, compound F. Data for F,R f =0.30(silica,petroleum ether / acetone 4.5:1); (MeOH, c 0.05); 1H NMR (400MHz, Acetone-d6) δ=5.13(s,1H),5.10–5.03(m,1H),4.83(d,J=6.9,1H),4.78(d,J=7.0,1H),4.59(dt,J=5.4,2.7 ,1H),4.49(d,J=1.7,2H),4.35(d,J=12.5,1H),3.84–3.77(m,1H),3.69–3.60(m,1H),2.75(d,J=5.9,1H),2.51(t,J=7.2, 1H),2.26(d,J=12.6,1H),2.23–2.13(m,2H),2.09(s,1H),2.03(s,1H),1.89(dd,J=13.7,2.7,1H),1.78(d,J=12.6,1H),1 .70–1.63(m,1H),1.61–1.50(m,2H),1.44(dt,J=13.8,7.0,1H),1.20(s,3H),1.13(s,3H),0.99–0.92(m,2H),0.02(s,9H); 13 C NMR (101MHz, Acetone-d6)δ=210.7,180.4,158.2,108.2,95.2,79.4,77.7,70.5,67.0,60.0,60.0, 55.4,47.6,47.5,42.7,41.8,38.5,32.8,32.5,32.1,22.0,19.2,18.8,–1.2; HRESIMS(m / z):[M+Na] + calcd for C 26 H 40 O6SiNa + 499.2486, found 499.2483.

[0103] (6) Preparation of intermediate G: Compound F (2.9 g, 5.5 mmol, 1.0 equiv) was dissolved in 2 mL of dichloromethane. The reaction was carried out at room temperature, and DHP (2.0 mL, 22 mmol, 4.0 equiv) and p-toluenesulfonic acid pyridinium salt (305 mg, 1.2 mmol, 0.2 equiv) were added sequentially. The reaction was allowed to proceed at room temperature for 15 minutes. After the reaction was confirmed to be complete by TLC, the reaction was quenched with saturated NaHCO3 (30 mL), extracted with EtOAc (3 × 400 mL), washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with petroleum ether / ethyl acetate = 10:1 to obtain amorphous oily compounds G1 and G2.

[0104] Data for G1:R f =0.29(silica,petroleum ether / acetone 6:1); (MeOH,c 0.08); 1 H NMR(600MHz,CDCl3)δ=5.44–5.39(m,1H),5.12(d,J=2.8,1H),4.93(d,J=7.1,1H),4.79(d,J=7.1,1H),4.75–4.72(m,1H),4.60–4.57(m,1H),4.48(s,2H),4.26(d,J=13.3,1H),4.04–3.98(m,1H),3.79(ddd,J=11.6,9.5,5.5,1H),3.58(ddd,J=11.5,9.5,5.7,1H),3.50(ddd,J=11.6,8.3,3.3,1H),2.77(d,J=5.8,1H),2.73(dd,J=11.7,2.9,1H),2.38(t,J=7.1,1H),2.18–2.08(m,2H),2.03–1.93(m,2H),1.86–1.76(m,2H),1.74–1.66(m,2H),1.65–1.59(m,1H),1.56–1.47(m,5H),1.41(dt,J=14.1,7.0,1H),1.20(s,3H),1.13(s,3H),0.98(ddd,J=13.6,11.7,5.7,1H),0.91(ddd,J=13.5,11.5,5.4,1H),0.02(s,9H); 13 C NMR(151MHz,CDCl3)δ=211.4,180.2,154.5,110.2,101.4,95.0,84.9,76.7,70.0,66.8,64.9,58.9,58.8,55.2,47.5,46.9,42.6,41.4,37.7,32.7,32.0,31.8,31.2,25.4,21.7,21.3,18.7,18.3,–1.3;HRESIMS(m / z):[M+Na] + calcd forC 31 H 48 O7SiNa + 583.3062,found583.3067.

[0105] Data for G2:R f=0.32(silica,petroleum ether / acetone 6:1); (MeOH,c 0.05); 1 H NMR(600MHz,CDCl3)δ=5.20–5.17(m,1H),5.08(d,J=2.8,1H),4.94(t,J=2.7,1H),4.90(d,J=7.5,1H),4.86(d,J=7.5,1H),4.82(d,J=10.1,1H),4.71(d,J=10.1,1H),4.45–4.39(m,1H),4.33(d,J=14.0,1H),3.85(ddd,J=12.0,9.5,5.3,1H),3.75–3.69(m,1H),3.56(ddd,J=11.8,9.5,5.7,1H),3.20(td,J=11.2,3.1,1H),2.79–2.74(m,2H),2.69(d,J=9.2,1H),2.25(d,J=14.0,1H),2.10(dd,J=13.8,11.9,1H),1.98(dd,J=13.8,2.3,1H),1.96–1.90(m,1H),1.86–1.78(m,2H),1.79–1.72(m,1H),1.64(d,J=12.3,2H),1.54–1.40(m,4H),1.39–1.31(m,2H),1.19(s,3H),1.13(s,3H),0.98(ddd,J=13.6,12.0,5.6,1H),0.90(ddd,J=13.5,11.7,5.2,1H),0.02(s,9H); 13 C NMR(151MHz,CDCl3)δ=208.5,180.8,151.9,108.6,104.2,95.7,84.7,77.4,71.3,66.6,64.9,59.5,56.7,56.5,48.2,47.3,41.4,40.3,38.6,37.1,32.2,31.9,31.5,25.0,22.3,20.4,19.1,18.2,–1.3;HRESIMS(m / z):[M+Na] + calcd for C 31 H 48 O7SiNa + 583.3062,found583.3060.

[0106] (7) Preparation of intermediate H: Compounds E1 and E2 (1.3 g + 1.2 g, 4.5 mmol, 1.0 equiv) were dissolved in 2 mL of tetrahydrofuran. The reaction was carried out in a cryogenic reactor at -40 °C and cooled for 10 minutes. LDA (5.0 mL, 2 M in THF, 9 mmol, 2.0 equiv) was added and reacted with the substrate for 40 minutes. Then oxaziridine (2.3 g, 9 mmol, 2.0 equiv) (CAS: 63160-13-40) was added and the reaction was continued at -40 °C for 2 hours. After the reaction was confirmed to be complete by TLC, the reaction was quenched with saturated NaHCO3 (30 mL), extracted with EtOAc (3 × 100 mL), washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated and purified by column chromatography with petroleum ether / ethyl acetate = 8:1 to obtain amorphous oily compounds H1 and H2.

[0107] Data for H1:R f =0.30(silica,petroleum ether / acetone 5:1); (MeOH, c 0.07); 1 H NMR (600MHz, CDCl3) δ = 5.39 (s, 1H), 5.11 (s, 1H), 4.88 (d, J = 7.1, 1H), 4.83 (d ,J=7.0,1H),4.77(s,1H),4.62(dd,J=6.5,2.5,1H),4.55(d,J=10.3,1H),4. 50(d,J=10.2,1H),4.10(d,J=13.5,1H),4.05–3.98(m,1H),3.77(ddd,J=11. 7,9.5,5.6,1H),3.59(ddd,J=11.6,9.5,5.8,1H),3.54–3.48(m,1H),2.76(s ,1H),2.74–2.68(m,1H),2.60(s,1H),2.41(d,J=13.4,1H),2.25(d,J=15.4, 1H),2.05(d,J=15.3,1H),1.91–1.86(m,1H),1.86–1.80(m,1H),1.80–1.75( m,1H),1.72–1.63(m,3H),1.58–1.48(m,6H),1.29(s,3H),1.26(s,3H),0.96 (ddd,J=13.6,11.6,5.7,1H),0.89(ddd,J=13.8,11.5,5.5,1H),0.02(s,9H); 13C NMR(151MHz,CDCl3)δ=211.4,179.1,154.5,110.0,100.8,95.4,84.3,80.6,77.6,69.5,66.9,64.5,58.7,58.3,57.1,56.8,39.9,38.0,35.5,34.9,32.9,31.7,31.1,25.5,25.5,20.9,18.9,18.2,–1.3;HRESIMS(m / z):[M+Na] + calcd forC 31 H 48 O8SiNa + 599.3011,found599.3011.

[0108] Data for H2:R f =0.32(silica,petroleum ether / acetone 5:1); (MeOH,c 0.07); 1 H NMR(400MHz,CDCl3)δ=5.22–5.14(m,1H),5.05(d,J=2.9,1H),4.99–4.83(m,4H),4.72(d,J=10.2,1H),4.52(dd,J=7.7,2.0,1H),4.15(d,J=14.0,1H),3.87–3.73(m,2H),3.57(ddd,J=11.7,9.5,5.7,1H),3.32–3.19(m,1H),2.98(d,J=8.8,1H),2.89–2.71(m,2H),2.50(d,J=14.0,1H),2.30(d,J=15.2,1H),2.04(d,J=15.2,1H),1.97–1.73(m,5H),1.71–1.64(m,1H),1.64–1.52(m,2H),1.52–1.37(m,4H),1.24(s,3H),1.24(s,3H),0.92(dtd,J=30.7,13.4,5.6,2H),0.01(s,9H); 13C NMR (101MHz, CDCl3) δ=208.6,179.8,152.2,108.3,103.3,96.0,84.3,81.0,78.2,70.4,66.7,64.5,59.0,58.7, 57.4,55.5,39.7,38.8,37.2,34.6,33.8,31.8,31.4,25.1,24.1,21.7,19.1,18.2,–1.3; HRESIMS(m / z):[M+Na] + calcd for C 31 H 48 O8SiNa + 599.3011, found 599.3005.

[0109] (8) Preparation of intermediate I: Compounds H1 and H2 (1.3 g, 2.6 mmol, 1.0 equiv) were dissolved in 1 mL of ethanol, and pyridinium p-toluenesulfonic acid salt (113 mg, 0.5 mmol, 0.2 equiv) was added. The reaction was carried out at 68 °C for 1 hour. The mixture was quenched with saturated NaHCO3 (30 mL), extracted with EtOAc (3 × 100 mL), washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with petroleum ether / ethyl acetate as eluent (5:1) to obtain amorphous solid compound I. f =0.41(silica,petroleum ether / acetone 3:1); (MeOH, c 0.04); 1HNMR(600MHz, CDCl3)δ=5.20(s,1H),5.15(s,1H),4.88(d,J=7.0,1H),4.69(d,J=7.1,1H),4.38(d,J=3.2,1H),4.15(d,J=10.1,1H),4 .09(dd,J=14.6,10.5,2H),3.77(ddd,J=11.5,9.4,5.2,1H),3.54(ddd,J=11.6,9.5,5.7,1H),3.34(d,J=3.9,1H),2.81(dd,J=11.5,5 .1,1H),2.75–2.72(m,2H),2.60(s,1H),2.24–2.14(m,2H),2.06(d,J=15.3,1H),2.01(m,1H),1.80(dd,J=12.7,5.2,1H),1.54–1.41( m,1H),1.30(s,3H),1.29–1.24(m,2H),1.20(s,3H),0.98(ddd,J=13.7,11.8,5.8,1H),0.90(ddd,J=13.9,11.7,5.4,1H),0.02(s,9H); 13 C NMR (151MHz, CDCl3) δ=210.8,178.6,156.4,109.7,93.6,80.4,80.3,77.1,68.8,66.9,58.1,57. 8,57.6,56.2,39.4,36.8,36.3,34.6,32.2,29.1,26.8,18.4,18.2,–1.3; HRESIMS(m / z):[M+Na] + calcd for C 26 H 40 O7SiNa + 515.2436, found 515.2433.

[0110] (9) Preparation of intermediate J: Compound I (700 mg, 1.4 mmol, 1.0 equiv) was dissolved in 1 mL of dichloromethane. Acetic anhydride (180 μL, 1.7 mmol, 1.2 equiv) and DMAP (210 mg, 1.7 mmol, 1.2 equiv) were added sequentially under ice bath conditions, and the reaction was carried out for 1 hour. The mixture was quenched with saturated NaHCO3 (30 mL), extracted with EtOAc (3 × 50 mL), washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with an eluent of petroleum ether / ethyl acetate = 5:1, yielding an amorphous solid compound J. Data for J:R f=0.34(silica,petroleum ether / acetone 4:1); (MeOH,c 0.04);mp 230–232℃; 1 H NMR(600MHz,CDCl3)δ=5.68(s,1H),5.10(s,1H),4.93(dd,J=2.6,1.4,1H),4.78(dd,J=7.3,1.0,1H),4.57(dd,J=7.3,1.1,1H),4.24(d,J=10.2,1H),4.19(d,J=10.2,1H),4.07(d,J=11.8,1H),3.75(m,1H),3.54–3.46(m,1H),2.88(s,1H),2.85–2.76(m,2H),2.67–2.62(m,1H),2.21(d,J=15.3,1H),2.16(s,1H),2.12–1.98(m,3H),1.88(dd,J=12.7,5.2,1H),1.68(d,J=12.7,1H),1.54–1.52(m,2H),1.32(s,3H),1.30–1.24(m,2H),1.22(s,3H),1.01–0.92(m,1H),0.92–0.82(m,1H),0.01(s,9H); 13 C NMR(151MHz,CDCl3)δ=209.3,178.8,170.3,153.4,109.9,93.7,80.5,78.4,76.4,68.8,66.6,57.8,57.6,56.4,56.2,39.6,37.6,36.9,34.9,31.9,30.5,26.3,21.4,18.6,18.2,–1.3;HRESIMS(m / z):[M+Na] + calcd for C 28 H 42 O8SiNa + 557.2541,found557.2539.

[0111] (10) Preparation of maoelactone A: Compound J (500 mg, 0.9 mmol) was dissolved in 1 mL of tetrahydrofuran, and trifluoroacetic acid (300 μL) was added under heating at 50 °C for 1 hour. The reaction was quenched with saturated NaHCO3 (30 mL), extracted with EtOAc (3 × 50 mL), washed with saturated brine (50 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with petroleum ether / ethyl acetate = 5:1 to obtain the amorphous solid compound maoelactone A. f =0.31(silica,petroleum ether / acetone 2:1); (MeOH, c 0.10); 1 HNMR(600MHz,Pyridine-d5)δ=8.75(s,1H),6.40(m,1H),5.11(br d,1H),5.00(br d,1H),4.87(d,J=10.5,1H),4.75(d,J=10.5,1H),4.57(dd,J=13.5,3.5, 1H), 3.27 (t, J = 6.5, 1H), 2.84 (d, J = 13.5, 1H), 2.66 (m, 1H), 2.42 (d, J = 15. 0,1H),2.33(d,J=15.0,1H),2.06(m,1H),2.05(s,3H),1.99(m,1H),1.88( dt,J=12.9,4.2,1H),1.76(m,2H),1.50(s,3H),1.46(s,3H),1.41(m,1H); 13 C NMR (151MHz, Pyridine-d5)δ=212.3,179.6,170.3,153.5,108.8,81.2,78.6,73.6,69.4,59.3 ,59.2,57.4,56.0,39.9,39.0,36.8,35.7,33.0,31.6,25.9,21.0,19.6; HRESIMS(m / z):[M+Na] + calcd for C 22 H 28 O7Na + 427.1727, found 427.1735.

[0112] (11) Preparation of intermediate L: Compound K (12 g, 33.0 mmol) was dissolved in 50 mL of acetone. Jones' reagent (10 mL) was added and the reaction was carried out for 15 minutes under ice bath conditions at 0 °C. After the reaction was detected to be complete by TLC, it was quenched with isopropanol (30 mL), diluted with water, extracted with EtOAc (3 × 500 mL), washed with saturated brine (100 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with eluent: petroleum ether / acetone = 4:1, to obtain amorphous solid compound L. The compound spectrum was consistent with the data in the literature (J.Med.Chem.2013,56,5048-5058).

[0113] (12) Preparation of intermediate M: Compound L (9.0 g, 24.9 mmol, 1 equiv) was dissolved in 30 mL of 1,2-dichloroethane. NaBH(OAc)3 (6.3 g, 29.8 mmol, 1.2 equiv) was added under 0°C ice bath conditions, followed by slow dropwise addition of acetic acid (300 μL) for 10 minutes. After the reaction was complete as detected by TLC, it was quenched with acetone (30 mL), diluted with water, extracted with EtOAc (3 × 500 mL), washed with saturated brine (100 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with eluent: petroleum ether / acetone = 6:1, yielding an amorphous solid compound M. Data for M,R f =0.41(silica,petroleum ether / acetone 2:1); (MeOH, c 0.09); 1 H NMR (600MHz, Acetone-d6) δ = 6.66 (d, J = 4.3, 1H), 5.26–5.15 (m, 3H), 5.11 (d, J = 3.9, 1H), 4.97–4.90 (m, 1H),4.84(t,J=3.7,1H),4.59(q,J=4.4,4.0,1H),4.21(dd,J=10.1,4.3,1H),3.88–3.81(m,1H),3.74( dd,J=7.4,3.7,1H),2.74–2.62(m,2H),2.51(dd,J=9.1,4.2,1H),2.32–2.24(m,1H),2.23–2.12(m,2H) ,2.00–1.92(m,1H),1.72–1.55(m,2H),1.50–1.40(m,1H),1.10(s,3H),0.96(s,3H),0.94–0.88(m,1H); 13C NMR (151MHz, Acetone-d6)δ=213.4,159.6,110.3,99.8,76.0,73.3,72.5,64.8,57.3,5 3.3,49.1,45.8,42.6,39.2,36.3,33.3,32.9,30.8,24.3,17.4; HRESIMS(m / z):[M+Na] + calcd for C 20 H 28 O6Na + 387.1778, found 387.1783.

[0114] (13) Preparation of intermediate N: Compound M (6.2 g, 17.0 mmol, 1.0 equiv) was dissolved in 15 mL of DCM, and DIPEA (11.3 mL, 68.0 mmol, 4.0 equiv) and TMSCl (8.6 mL, 68.0 mmol, 4.0 equiv) were added sequentially under ice bath conditions at 0 °C. After reacting at 0 °C for 30 minutes, the mixture was concentrated under reduced pressure. The concentrated product was dissolved in acetonitrile, and then DBU (3.8 mL, 25.5 mmol, 1.5 equiv) and p-toluenesulfonyl azide (7.5 mL, 75% in EA, 25.5 mmol, 1.5 equiv) were added sequentially. After reacting for 2 hours, TBAF (17.8 g, 68 mmol, 4.0 equiv) was added dropwise and reacted for 30 minutes. After the reaction was detected to be complete by TLC, the product was diluted with water and extracted with EtOAc (3 × 500 mL). The product was washed with saturated brine (100 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with petroleum ether / acetone as the eluent at a ratio of 6:1 to give an amorphous solid compound N. Data for N,R f =0.29(silica,CHCl3 / MeOH 3.8:0.2); (MeOH, c 0.13); 1H NMR (600MHz, Acetone-d6) δ=6.82(s,1H),5.34–5.25(m,1H),5.22(d,J=3.1,1H),5.17(d,J=2.5,1H),5.11–5 .07(m,1H),4.91(t,J=2.6,1H),4.82(d,J=2.6,1H),4.66(s,1H),4.20(d,J=9.5,1H),3.87(dd,J=9.6,2.0,1 H),3.71(dd,J=7.9,3.1,1H),2.84(d,J=14.0,1H),2.55–2.44(m,3H),2.31(dt,J=12.9,8.9,1H),1.94(d,J= 7.8,1H),1.88–1.77(m,1H),1.41(td,J=12.5,8.0,1H),1.23(dt,J=14.1,7.0,1H),1.19(s,3H),1.12(s,3H); 13 C NMR (151MHz, Acetone-d6) δ = 193.3, 159.8, 110.0, 99.5, 76.0, 72.8, 72.5, 65.5, 64.4, 5 6.0,53.7,47.1,45.5,43.3,38.0,33.6,33.1,30.5,21.2,17.9; HRESIMS(m / z):[M+Na] + calcd for C 20 H 26 N2O6Na + 413.1683, found 413.1680.

[0115] (14) Preparation of intermediate O: Compound N (4.6 g, 9.4 mmol, 1.0 equiv) was dissolved in 10 mL of DCM. NaHCO3 (2.4 g, 28.2 mmol, 3.0 equiv) and Dess-Martin reagent (4.0 g, 9.4 mmol, 1.0 equiv) were added sequentially under ice bath conditions at 0 °C. The reaction was carried out at 0 °C for 10 min. After the reaction was confirmed to be complete by TLC, it was quenched with Na2O3S2, diluted with water, extracted with EtOAc (3 × 500 mL), washed with saturated brine (100 mL), dried over anhydrous MgSO4, filtered, concentrated, and purified by column chromatography with petroleum ether / acetone = 6:1 to obtain the amorphous solid compound O. Data for O,R f =0.31(silica,petroleum ether / acetone 2:1); (MeOH, c 0.07); 1H NMR (600MHz, Acetone-d6) δ = 6.68 (s, 1H), 6.09 (s, 1H), 5.61 (s, 1H), 5.50 (d, J = 11.4, 1H), 5.36 ( s,1H),4.96(s,1H),4.20(dd,J=9.9,1.5,1H),3.94(dd,J=9.9,1.7,1H),3.68(dd,J=11.4,8.8,1 H),3.00(d,J=9.5,1H),2.83(d,J=14.0,1H),2.50–2.44(m,2H),2.18–2.14(m,1H),2.07–2.06(m ,1H),1.72(dd,J=8.8,1.4,1H),1.59–1.53(m,1H),1.51–1.46(m,1H),1.24(s,3H),1.13(s,3H); 13 C NMR (151MHz, Acetone-d6)δ=207.6,192.4,153.2,120.7,99.1,73.5,73.3,65.9,64.9, 62.8,59.9,51.2,47.5,44.0,38.1,34.0,31.0,30.1,21.2,20.2; HRESIMS(m / z):[M+Na] + calcd for C 20 H 24 N2O6Na + 411.1527, found 411.1521.

[0116] (15) Preparation of Maoelactone B: Compound O (3.6 g, 9.4 mmol) was dissolved in 4 mL of toluene and reacted at 110 °C with stirring for two hours. After the reaction was complete as detected by TLC, the reaction was moved to room temperature and cooled. The mixture was then concentrated under reduced pressure and purified by column chromatography with petroleum ether / ethyl acetate as eluent (6:1) to obtain an amorphous white solid compound, Maoelactone B. f =0.30(silica,CHCl3 / MeOH 3.8:0.2); (MeOH, c 0.20); 1H NMR (600MHz, CDCl3) δ=6.26(s,1H),5.65(s,1H),4.64(s,1H),4.37(d,J=10.4,1H),4.21(t,J= 10.7,2H),4.05(d,J=10.1,1H),3.83(s,1H),3.16(d,J=6.9,1H),2.66(dd,J=11.4,3.2,1H),2 .40(ddd,J=14.2,8.4,5.7,2H),2.12(dd,J=14.1,11.4,1H),2.07(d,J=12.0,1H),2.03(dd,J= 14.0,3.2,1H),1.82(dtd,J=14.1,7.9,1.9,1H),1.69–1.58(m,2H),1.23(s,3H),1.15(s,3H); 13 C NMR (151MHz, CDCl3) δ = 208.9, 201.4, 178.9, 147.6, 122.5, 73.9, 72.9, 68.9, 68.8, 62 .9,54.0,52.5,46.8,46.4,43.7,41.3,31.6,29.8,22.1,19.3; HRESIMS(m / z):[M+Na] + calcd for C 20 H 24 O6Na + 383.1465, found 383.1475.

[0117] Example 3

[0118] Cellular-level antitumor activity test of the compounds of this invention.

[0119] 1. Experimental Objective

[0120] The antitumor activity of the compounds of this invention was tested by measuring their growth inhibitory activity against human tumor cells to evaluate their in vitro antitumor activity.

[0121] 2. Experimental Materials

[0122] The human non-small cell lung cancer cell line A549, human liver cancer cell line HepG2, human chronic myeloid leukemia cell line K562, and human acute promyelocytic leukemia cell line HL60 were all donated by the research group of Professor Li Jia at the Shanghai Institute of Materia Medica, Chinese Academy of Sciences. The human breast cancer cell line MDA-MB-435 was purchased from the Cell Resource Center of the Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

[0123] 3. Testing Principle

[0124] Cell proliferation was detected using the MTS colorimetric assay. MTS is a novel MTT analog, its full name being 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfopheny)-2H-tetrazolium, a yellow dye. Succinate dehydrogenase in the mitochondria of living cells can metabolize and reduce MTS, generating a soluble formazan compound. The formazan content can be measured using a microplate reader at 490 nm. Under normal circumstances, the amount of formazan produced is directly proportional to the number of living cells; therefore, the number of living cells can be inferred from the optical density (OD) value.

[0125] 4. Experimental Methods

[0126] (1) Cell seeding: Prepare a single cell suspension using culture medium (DMEM or RMPI1640) containing 10% fetal bovine serum, and seed 3000-5000 cells per well into a 96-well plate with a volume of 100 μl per well. The cells should be seeded and cultured 12-24 hours in advance.

[0127] (2) Add the solution of the compound to be tested: the compound is dissolved in DMSO, the compound is initially screened at a concentration of 40 μM, the final volume of each well is 200 μl, and each treatment is set with 3 replicates.

[0128] (3) Color development: After culturing at 37 degrees Celsius for 48 hours, discard the culture medium in the wells and add 20 μl of MTS solution and 100 μl of culture medium to each well; set up 3 blank replicates (a mixture of 20 μl of MTS solution and 100 μl of culture medium), and continue incubation for 2 to 4 hours to allow the reaction to proceed fully before measuring the light absorbance.

[0129] (4) Colorimetric analysis: Select a wavelength of 492nm, use a multi-functional microplate reader (MULTISKAN FC) to read the absorbance values ​​of each well, record the results, and after data processing, plot the cell inhibition rate graph with the compound number as the x-axis and the cell inhibition rate as the y-axis.

[0130] (5) Positive control compounds: Two positive compounds, cisplatin (DDP) and paclitaxel (Taxol), were set up in each experiment. Cell growth curves were plotted with concentration on the x-axis and cell viability on the y-axis. The IC50 value of the compounds was calculated using the Reed and Muench method.

[0131] 5. Compound test results

[0132] Table 1. Inhibitory activity of compounds against the proliferation of various tumor cells

[0133]

[0134] Formulation Examples

[0135] 1. Take pilocarpine A and / or pilocarpine B, add them to the excipients at a weight ratio of 1:1, and granulate and compress into tablets.

[0136] 2. Take pilocarpine A and / or pilocarpine B, add them to the excipients at a weight ratio of 1:2, and granulate and compress into tablets.

[0137] 3. Take pilocarpine A and / or pilocarpine B and prepare capsules according to conventional capsule preparation methods.

[0138] 4. Take pilocarpine A and / or pilocarpine B, and then prepare tablets according to the following method:

[0139]

[0140] 5. Capsules: Take 100mg of pilocarpine A and / or pilocarpine B, appropriate amount of starch, appropriate amount of stearic acid mold. Preparation method: Mix the compound with the excipients, sieve, mix evenly in a suitable container, and fill the resulting mixture into hard gelatin capsules.

[0141] 6. Nasal spray: Take 80mg of pilocarpine A and / or pilocarpine B.

[0142]

[0143] Preparation method: Add one component at a time to an appropriate volume of double-distilled styrax water while stirring, until completely dissolved, then add the next component. After adding water to 2 mL, filter the solution through a sterile filter, bottle it, and divide it into appropriate dosages.

[0144] 7. Droplets: Take 1g of pilocarpine A and / or pilocarpine B, and 9g of polyethylene glycol. Preparation: Weigh pilocarpine A according to the above prescription, add an appropriate amount of anhydrous ethanol, dissolve by gentle heating, then add to the prescribed amount of polyethylene glycol melt (keep warm in a 60℃ water bath), stir and mix evenly until the ethanol evaporates completely, let stand in a 60℃ water bath for 30 minutes until the air bubbles are removed, transfer the above-mentioned well-mixed melt with the air bubbles removed into a storage cylinder, and under the condition of keeping warm at 80-85℃, control the dripping rate and drip it drop by drop into the condensate. After complete condensation, pour off the condensate, collect the droplets, drain them, remove the condensate from the droplets with filter paper, and place them in a silica gel desiccator or air dry.

Claims

1. Lobelanidin A and Lobelanidin B as shown in the following structural formula, the Lobelanidin A and Lobelanidin B are enanti-kaurene type diterpenoids, as a structural modification precursor, 。 2. The process for the preparation of rossmaureine A as claimed in claim 1, wherein, The method takes Lobelanidin A as a starting material to obtain an intermediate E through four-step reactions first, the intermediate E is constructed through a key intramolecular Wolff rearrangement cascade lactonization reaction (5), and then Lobelanidin A is obtained through five-step reactions, and the preparation process is as follows: 。 3. The process for the preparation of pinnatin A as claimed in claim 2, wherein, The intramolecular Wolff rearrangement cascade lactonization reaction (5) step includes the following conditions: 。 4. The process for the preparation of picroside A as claimed in claim 1, wherein, The method comprises the following steps: (1) Preparation of intermediate B: Dissolve compound A in 1-100 mL of dichloromethane, add 1-100 mL of diisopropylethylamine, and heat at 0°C. o 1–100 mL of 2-(trimethylsilyl)ethoxymethyl chloride was slowly added dropwise under ice bath conditions. The reaction was then allowed to proceed at room temperature for 4 hours. After the reaction was confirmed to be complete by TLC, it was quenched with saturated sodium bicarbonate, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate B by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. ； (2) Preparation of intermediate C: Intermediate B was dissolved in 1-100 mL of tetrahydrofuran, placed in a -50 o C low temperature reactor, cooled for 15 minutes, then slowly added sodium borohydride 1-15 g, reacted for 30 minutes, after TLC detection of the reaction was complete, quenched with acetone, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, concentrated and purified by column chromatography to obtain an amorphous solid compound, which was identified as intermediate C by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. ； (3) Preparation of intermediate D: intermediate C was dissolved in 1-100 mL of methanol, first added nickel dichloride hexahydrate, stirred for half an hour; then placed in a low-temperature reactor of intermediate C, cooled for half an hour, slowly added sodium borohydride 1-15 g in three portions, the reaction solution immediately turned black after addition, reacted for 1 hour, then moved to room temperature and continued to react for 1 hour, after TLC detection showed that the reaction was complete, quenched with saturated sodium bicarbonate, added 1-100 g of diatomite after quenching, stirred uniformly, and then extracted with ethyl acetate, washed with saturated brine 50 mL, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound, which was identified as intermediate D by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance, o C. ； (4) Preparation of intermediate E: Intermediate D is dissolved in 1-100 mL of acetonitrile, 1,8-diazabicyclo[5.4.0]undecene 1-20 mL and p-toluenesulfonyl chloride azide 1-20 mL are added in turn, the reaction is placed at room temperature and fully reacted for 2 hours, after the reaction is completely detected by TLC, saturated sodium bicarbonate is used for quenching, ethyl acetate is extracted, saturated brine is washed, anhydrous magnesium sulfate is dried, filtered, concentrated and then column chromatography is used for purification to obtain an amorphous solid compound, which is identified as intermediate E by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance, ； (5) Preparation of intermediate F: Intermediate E was dissolved in 1-10 mL of toluene and placed in a 110 o C under heating and stirring for two hours. After the reaction was complete, as determined by TLC, the reaction was moved to room temperature and allowed to cool. The reaction was then directly concentrated under reduced pressure. The resulting residue was purified by column chromatography to yield amorphous white solid compound, which was identified as intermediate F by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. ； (6) Preparation of intermediate G: Intermediate F is dissolved in 1-10 mL of dichloromethane, 3,4-dihydro-2H-pyran 1-10 mL and p-toluenesulfonic acid pyridine salt 0.5-5 g are added in turn under room temperature, and the reaction is fully reacted for 15 minutes under room temperature, after the reaction is completely detected by TLC, saturated sodium bicarbonate is used for quenching, ethyl acetate is extracted, saturated brine is washed, anhydrous magnesium sulfate is dried, filtered, concentrated and then column chromatography is used for purification to obtain an oil compound, which is identified as intermediate G by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance, ； (7) Preparation of intermediate H: Intermediate G was dissolved in 1-10 mL of tetrahydrofuran and the reaction was placed in a -40 o C low temperature reactor for 10 minutes. After cooling, lithium diisopropylamine 1-10 mL was added and allowed to react with the substrate for 40 minutes. Then, oxaziridine 1-10 g was added and allowed to react for 2 hours at -40 o C. After the reaction was complete, as determined by TLC, it was quenched with saturated sodium bicarbonate, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to give an oil. The compound was identified as intermediate H by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. ； (8) Preparation of intermediate I: Intermediate H was dissolved in 1-10 mL of ethanol, and p-toluenesulfonic acid pyridine salt 0.1-5 g was added. The reaction was stirred for 1 hour in 68 o C, quenched with saturated sodium bicarbonate, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to give an oil, which was identified as intermediate I by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. ； (9) Preparation of intermediate J: Intermediate I is dissolved in 1-10 mL of dichloromethane, acetic anhydride 0.1-1 mL and 4-dimethylaminopyridine 0.1-1 g are added in turn under ice bath condition, and the reaction is reacted for 1 hour, saturated sodium bicarbonate is used for quenching, ethyl acetate is extracted, saturated brine is washed, anhydrous magnesium sulfate is dried, filtered, concentrated and then column chromatography is used for purification to obtain an amorphous solid compound, which is identified as intermediate J by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance, ； (10) Preparation of MaoCaolide A: Intermediate J was dissolved in 1 mL of tetrahydrofuran, 0.1 mL of trifluoroacetic acid was added under heating condition for 1 hour. Saturation sodium bicarbonate was used to quench, ethyl acetate was used to extract, 50 mL of saturated brine was used to wash, anhydrous magnesium sulfate was used to dry, filtered, concentrated and purified by column chromatography to obtain a solid compound, which was identified as MaoCaolide A by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. o C trifluoroacetic acid was added under heating condition for 1 hour. Saturation sodium bicarbonate was used to quench, ethyl acetate was used to extract, 50 mL of saturated brine was used to wash, anhydrous magnesium sulfate was used to dry, filtered, concentrated and purified by column chromatography to obtain a solid compound, which was identified as MaoCaolide A by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. 。 5. The process for the preparation of pterosin B as claimed in claim 1, wherein, The preparation process of the method is as follows: 。 6. The process for the preparation of pterosin B as claimed in claim 1, wherein, The method comprises the following steps: (11) Preparation of intermediate L: Compound K was dissolved in 1-100 mL of acetone, 0 o Jones reagent 10 mL was added under ice bath condition, after TLC detection of the reaction completion, the reaction was quenched with isopropyl alcohol, diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, concentrated and purified by column chromatography to give amorphous solid compound L, which was identified as intermediate L by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. ； (12) Preparation of intermediate M: Intermediate L was dissolved in 1-100 mL of 1,2-dichloroethane, 1-50 g of sodium triacetoxyborohydride was added under ice bath condition, followed by slow dropwise addition of acetic acid 0.1-1 mL. The reaction was monitored by TLC for completion. After completion, the reaction was quenched with acetone, diluted with water and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by column chromatography to give the compound as an amorphous solid. The compound was identified as intermediate M by mass, 1D and 2D NMR. o C ice bath condition, followed by slow dropwise addition of acetic acid 0.1-1 mL. The reaction was monitored by TLC for completion. After completion, the reaction was quenched with acetone, diluted with water and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by column chromatography to give the compound as an amorphous solid. The compound was identified as intermediate M by mass, 1D and 2D NMR. ； (13) Preparation of intermediate N: Dissolve intermediate M in 1-100 mL of dichloromethane, and at 0 o Under ice bath conditions, 1-50 mL of N,N-diisopropylethylamine and 1-50 mL of trimethylchlorosilane were added sequentially. The mixture was reacted under ice bath conditions for 30 minutes, followed by concentration under reduced pressure. The concentrated product was dissolved in acetonitrile, and then 1-50 mL of 1,8-diazabicyclo[5.4.0]undecene and 1-50 mL of p-toluenesulfonyl azide were added sequentially. After reacting for 2 hours, 1-50 g of tetrabutylammonium fluoride was added dropwise, and the reaction was allowed to proceed for another 30 minutes. After the reaction was confirmed to be complete by TLC, the mixture was diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. Mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance (NMR) identified the compound as intermediate N. ； (14) Preparation of intermediate O: Dissolve intermediate N in 1-100 mL of dichloromethane, and at 0 o Sodium bicarbonate (1-10 g) and Desmond-Martin reagent (1-10 g) were added sequentially under ice bath conditions. The reaction was carried out for 10 minutes under ice bath conditions. After the reaction was detected to be complete by TLC, it was quenched with sodium thiosulfate, diluted with water, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous magnesium sulfate, filtered, concentrated, and purified by column chromatography to obtain an amorphous solid compound. The compound was identified as intermediate O by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. ； (15) Preparation of MaoCaolide B: Intermediate O was dissolved in 1-50 mL of toluene and placed in a 110 o C under heating and stirring for 2 hours until the reaction was complete. The reaction was moved to room temperature and cooled. The reaction was directly concentrated under reduced pressure. The concentrated product was purified by column chromatography to obtain an amorphous white solid. The compound was identified as MaoCaolide B by mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance. 。 7. The use of Lobelanidin A and / or Lobelanidin B of claim 1 in the preparation of an antitumor drug.

8. The use of Lobelanidin A and / or Lobelanidin B of claim 1 in the preparation of a drug for treating cervical cancer, breast cancer and colon cancer.

9. A pharmaceutical composition comprising Lobelanidin A and / or Lobelanidin B of claim 1 and at least one pharmaceutically acceptable carrier.

10. The use of the pharmaceutical composition of claim 9 in the preparation of a drug for treating cervical cancer, breast cancer and colon cancer.

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