Ppd ring-opening epoxy-substituted derivatives, process for their preparation and use

Abstract

The application discloses PPD open ring epoxy substitution derivatives, a structural formula of which is shown as formula 8 or formula 9, or a pharmaceutically acceptable salt of a compound shown as formula 8 or formula 9. The application also discloses a preparation method of the PPD open ring epoxy substitution derivatives, and application of the PPD open ring epoxy substitution derivatives and the pharmaceutically acceptable salt thereof in preparation of a tumor drug resistance reversal agent / tumor drug sensitizer, or a tumor drug resistance reversal agent / tumor drug sensitizer containing a pharmaceutically acceptable carrier. The PPD open ring epoxy substitution derivatives disclosed by the application are synthesized for the first time, the anti-tumor MDR activity thereof is found for the first time, the cytotoxicity is low, and the covalent cross-linking group makes the PPD open ring epoxy substitution derivatives 8a-8b and 9a-9h have better tumor drug resistance reversal activity, and the effect is obviously better than that of a positive control drug.

Description

Technical Field

[0001] This invention relates to the fields of organic synthesis and medicinal chemistry, specifically to a novel class of PPD ring-opening epoxy-substituted derivatives, their preparation methods, and their applications in the pharmaceutical field. Background Technology

[0002] Multidrug resistance (MDR) is a major cause of chemotherapy failure in cancer treatment. The development of MDR prevents anti-tumor drugs from reaching tumor cells, rendering them ineffective and posing a significant challenge to current cancer therapy and drug development. However, existing MDR reversal agents suffer from low efficacy and high toxicity. Therefore, developing novel, low-toxicity, and highly effective MDR reversal agents is a hot topic in cancer therapy and drug research.

[0003] Ginseng, hailed as the "King of Herbs," is a widely used traditional Chinese medicine. Ginsenosides, the active ingredients in ginseng, possess various pharmacological activities, including antioxidant, anti-inflammatory, antibacterial, anticancer, and anti-myocardial ischemia effects. Among them, 20S-protopanaxadiol (PPD), as the main aglycone, is now commonly used as an adjuvant drug during cancer treatment. 20S-PPD is readily metabolized in vivo into a structure with a furan ring side chain, and its 3-hydroxyl group is also highly susceptible to hepatic metabolism. Therefore, if the furan ring side chain of PPD is selected, and a series of poorly metabolized derivatives are constructed through ring-opening of the A ring, it is possible to obtain novel P-gp inhibitors with high activity and low toxicity. Summary of the Invention

[0004] To design novel PPD derivatives with novel structures capable of reversing P-glycoprotein-mediated tumor MDR activity, and further to provide a drug and composition for treating tumors, this invention provides a series of derivatives having the structural features shown in formulas A, B, and C, and their pharmaceutically acceptable salts. The antitumor MDR activity of these compounds is discovered for the first time, and the compounds are synthesized for the first time.

[0005] The technical solution adopted in this invention is:

[0006] PPD ring-opening epoxy-substituted derivatives, having the structural formula shown in Formula 8 or Formula 9, or pharmaceutically acceptable salts of compounds shown in Formula 8 or Formula 9.

[0007]

[0008] Among them, R1 and R2 are each independent of each other. x -KY-, where Y represents NH or O, K represents methylene or is absent, and R... xThe heterocyclic or heteroaromatic group is a C3-C10 heterocyclic group or heteroaromatic group that is not substituted or is substituted by one or more substituents; the substituent is a C1-C10 alkyl or tert-butoxycarbonyl group. The heterocyclic or heteroaromatic group of the present invention refers to a heterocyclic or heteroaromatic group containing one or both of N and O atoms in the ring.

[0009] Preferred R x It is one of pyrazine, pyridine, aziridine, thiophene, piperidine, furan, tetrahydrofuran, and thiazole.

[0010] Furthermore, R1 preferably represents 1-methyl-(2-thiophene)-1-yl or 3-N-Boc-azacyclobutane-1-yl; R2 represents 4-methylpiperidin-1-yl, 1-methyl-(2-furan)-1-yl, 1-methyl-(2-thiazolyl)-1-yl, 1-methyl-(2-thiophene)-1-yl, 3-N-Boc-azacyclobutane-1-yl, 4-N-Boc-piperidin-1-yl, 3-oxacyclobutane-1-yl, or 1-methyl-(2-pyridin)-1-yl.

[0011] More preferably, the compound represented by Formula 8 or Formula 9 is one of the following:

[0012]

[0013] The names of the compounds are as follows:

[0014] (20S,24R)-epoxy-3,4-open-ring-3-(2-thienylmethylamine-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 8a);

[0015] (20S,24R)-epoxy-3,4-open-ring-3-(3-N-Boc-azacyclobutaneamine-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 8b);

[0016] (20S,24R)-epoxy-3,4-open-ring-3-(4-methylpiperidinol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9a);

[0017] (20S,24R)-epoxy-3,4-open-ring-3-(furfuryl-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9b);

[0018] (20S,24R)-epoxy-3,4-open-ring-3-(2-thiazol-methanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9c);

[0019] (20S,24R)-epoxy-3,4-open-ring-3-(2-thiophene-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9d);

[0020] (20S,24R)-epoxy-3,4-open-ring-3-(3-N-Boc-azacyclobutanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9e);

[0021] (20S,24R)-epoxy-3,4-open-ring-3-(4-N-Boc-piperidinol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9f);

[0022] (20S,24R)-epoxy-3,4-open-ring-3-(3-oxacyclobutanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9g);

[0023] (20S,24R)-epoxy-3,4-open-ring-3-(2-pyridinylmethanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9h).

[0024] More preferably, the PPD ring-opening epoxy-substituted derivatives are compounds 8a, 8b, 9c, 9d, 9e, and 9f.

[0025] The present invention also provides the use of the PPD ring-opening epoxy-substituted derivatives of Formula 8 or Formula 9 and their pharmaceutically acceptable salts in the preparation of tumor resistance reversal agents / tumor drug sensitizers, or in the preparation of tumor resistance reversal agents / tumor drug sensitizers comprising a pharmaceutically acceptable carrier; furthermore, the PPD ring-opening epoxy-substituted derivatives of Formula 8 or Formula 9 and their pharmaceutically acceptable salts can be used to prepare tumor resistance reversal agents / tumor drug sensitizers that overcome P-glycoprotein-mediated tumor resistance or to prepare tumor resistance reversal agents / tumor drug sensitizers comprising a pharmaceutically acceptable carrier.

[0026] Furthermore, in the aforementioned applications, the PPD ring-opening epoxy-substituted derivatives are compounds 8a, 8b, 9c, 9d, 9e, and 9f.

[0027] The present invention also provides the use of the PPD ring-opening epoxy-substituted derivatives of Formula 8 or Formula 9 and their pharmaceutically acceptable salts in the preparation of antitumor drugs. In the method of application, the antitumor drugs include clinical antitumor drugs and tumor resistance reversal agents / tumor drug sensitizers, wherein the tumor resistance reversal agents / tumor drug sensitizers are the PPD ring-opening epoxy-substituted derivatives of Formula 8 or Formula 9 and their pharmaceutically acceptable salts.

[0028] Furthermore, the tumor in question is breast cancer, colon cancer, cervical cancer, liver cancer, stomach cancer, or lung cancer.

[0029] The clinical antitumor drug mentioned is paclitaxel.

[0030] Furthermore, in the aforementioned applications, the PPD ring-opening epoxy-substituted derivatives are preferably compounds 8a, 8b, 9c, 9d, 9e, and 9f.

[0031] The present invention also provides the use of the PPD ring-opening epoxy-substituted derivatives of Formula 8 or Formula 9 and their pharmaceutically acceptable salts in the preparation of adjuvant medicines or health products for cancer patients undergoing chemotherapy, and the application is not limited to the treatment and prevention of multidrug-resistant cancer.

[0032] The pharmaceutically acceptable salts described in this invention refer to conventional acid addition salts that have the same pharmaceutical efficacy as the compound and are formed with suitable non-toxic organic or inorganic acids.

[0033] The present invention also provides a pharmaceutical composition for resisting multidrug resistance, the pharmaceutical composition comprising the PPD ring-opening epoxy-substituted derivatives of Formula 8 or Formula 9 and their pharmaceutically acceptable salts, and may also be formulated into pharmaceutical preparations such as tablets, capsules, powders, syrups, suspensions, injections, etc., by adding pharmaceutically acceptable carriers; and may also be added with commonly used pharmaceutical excipients such as sweeteners, diluents, and fillers.

[0034] Furthermore, in the pharmaceutical composition, the PPD ring-opening epoxy-substituted derivative is preferably compound 8a, 8b, 9c, 9d, 9e, or 9f.

[0035] The pharmaceutical composition provided by this invention can be administered clinically via oral administration, injection, or other methods.

[0036] The clinical dosage of the pharmaceutical composition of the present invention is 0.01 mg to 1000 mg / day of the active ingredient, and may deviate from this range depending on the severity of the condition or the dosage form.

[0037] Furthermore, the present invention also provides a method for preparing the PPD ring-opening epoxy-substituted derivative shown in Formula 8 or Formula 9, the method being as shown in the following reaction formula:

[0038]

[0039] The method includes the following steps:

[0040] (1) 24R-Pyxinol as shown in Formula 1 is fed with pyridine chlorochromate (PCC) in a molar ratio of 1:1 to 8 to carry out an oxidation reaction to obtain compound 3;

[0041] The reaction solvent in step (1) is an aprotic solvent, preferably dichloromethane (DCM) or tetrahydrofuran;

[0042] The reaction temperature for the oxidation reaction is -20℃ to 60℃; preferably, the reaction temperature is 0℃ to 30℃, and more preferably, room temperature.

[0043] The oxidation reaction takes 3 to 24 hours; the preferred reaction time is 3 to 12 hours. The reaction is typically monitored by TLC until completion.

[0044] After the reaction was completed, the reaction solution was post-processed to obtain compound 3. The post-processing method of the reaction solution was as follows: the reaction solution was filtered, vacuum concentrated, and then purified by silica gel column chromatography (SGCC) to obtain compound 3.

[0045] (2) Compound 3 was reacted with m-chloroperoxybenzoic acid (m-CPBA) in a Baeyer-Villiger reaction to prepare compound 4;

[0046] The molar ratio of compound 3 to m-chloroperoxybenzoic acid (m-CPBA) is 1:3 to 15.

[0047] Furthermore, the reaction solvent in step (2) is an aprotic solvent, preferably dichloromethane (DCM) or tetrahydrofuran;

[0048] The Baeyer-Villiger reaction is carried out at a temperature of -10°C to 40°C, preferably 5°C to 30°C, and more preferably at room temperature; the reaction time is 5 to 12 hours.

[0049] After the reaction was completed, the resulting reaction solution was post-processed to obtain compound 4. The post-processing method of the reaction solution was as follows: the reaction solution was stirred, filtered, vacuum concentrated, and then purified by silica gel column chromatography (SGCC) to obtain compound 4.

[0050] (3) Compound 4 was reacted with p-toluenesulfonamide (P-TSA) in an acidic ring-opening reaction to obtain compound 5;

[0051] The molar ratio of compound 4 to p-toluenesulfonamide (P-TSA) is 1:3 to 15.

[0052] Furthermore, the reaction solvent in step (3) is an aprotic solvent, preferably dichloromethane (DCM) or tetrahydrofuran;

[0053] The reaction temperature for the acidic ring-opening reaction is -10℃ to 60℃, preferably 5℃ to 30℃, and more preferably room temperature; the reaction time is 5 to 18 hours.

[0054] After the reaction was completed, the resulting reaction solution was post-processed to obtain compound 5. The post-processing method of the reaction solution was as follows: the reaction solution was stirred, filtered, vacuum concentrated, and then purified by silica gel column chromatography (SGCC) to obtain compound 5.

[0055] (4) Compound 5 is reacted with amino-containing heterocyclic compound R1-NH2 or hydroxyl-containing heterocyclic compound R2-OH by amide reaction or esterification reaction to obtain compound 6 or compound 7, respectively.

[0056] The molar ratio of compound 5 to the amino-containing heterocyclic compound R1-NH2 or the hydroxyl-containing heterocyclic compound R2-OH is 1:1.2 to 16.

[0057] Furthermore, the catalysts for the amide reaction are HBTU (benzotriazole-N,N,N,N-tetramethylurea hexafluorophosphate) and triethylamine, and the molar ratio of compound 5 to HBTU and triethylamine is 1:1.3-5:2-10;

[0058] Furthermore, the catalysts for the esterification reaction are EDCI and DMAP, and the molar ratio of compound 5 to EDCI and DMAP is 1:2 to 5:0.1 to 1.

[0059] Furthermore, the reaction solvent in step (4) is an aprotic solvent, preferably N,N-dimethylformamide or dichloromethane (DCM);

[0060] The reaction temperature for the amide reaction or esterification reaction is -10℃ to 40℃, preferably 0℃ to 30℃, and more preferably room temperature; the reaction time is 0.5 to 16 hours, preferably 0.5 to 10 hours.

[0061] After the reaction was completed, the resulting reaction solution was post-processed to obtain compound 6 or compound 7, respectively. The post-processing method of the reaction solution was as follows: the reaction solution was quenched by adding water, extracted with ethyl acetate, the organic phase was washed, dried and then filtered and concentrated, and the concentrated sample was purified by silica gel column chromatography to obtain compound 6 or compound 7, respectively.

[0062] (5) Compound 6 or Compound 7 is fed with m-chloroperoxybenzoic acid (m-CPBA) at a molar ratio of 1:1.2 to 12 to carry out a cyclization reaction, and PPD ring-opening epoxy-substituted derivatives of Formula 8 or Formula 9 are prepared respectively.

[0063] In the cyclization reaction of step (5), sodium bicarbonate is also added, and the molar ratio of compound 6 or compound 7 to sodium bicarbonate is preferably 1:5 to 15.

[0064] The reaction solvent in step (5) is an aprotic solvent, preferably dichloromethane (DCM) or tetrahydrofuran;

[0065] The reaction temperature for the cyclization reaction is -10℃ to 60℃; the preferred reaction temperature is 0℃ to 30℃.

[0066] The cyclization reaction takes 3 to 24 hours; the preferred reaction time is 4 to 12 hours.

[0067] After the reaction is completed, the reaction solution is post-processed to obtain the PPD ring-opening epoxy-substituted derivatives represented by Formula 8 or Formula 9. The post-processing method of the reaction solution is as follows: the reaction solution is quenched by adding water, extracted with ethyl acetate, the organic phase is washed, dried and then filtered and concentrated, and the concentrated sample is purified by silica gel column chromatography to obtain the PPD ring-opening epoxy-substituted derivatives represented by Formula 8 or Formula 9.

[0068] The present invention has the following advantages over the prior art:

[0069] 1. The PPD ring-opening epoxy-substituted derivatives and their medically acceptable salts shown in Formulas 8 and 9 provided by this invention are synthesized for the first time, and their antitumor MDR activity is discovered for the first time.

[0070] 2. The PPD ring-opening epoxy-substituted derivatives of formulas (8a-8b) and (9a-9h) of this invention exhibit lower cytotoxicity than verapamil (Vrp), a classic P-glycoprotein inhibitor with relatively low toxicity. For example, at a drug concentration of 30 μM, the survival rate of Vrp-treated KBV tumor cells is approximately 40%, while compounds 8a-8b and 9a-9h show no cytotoxicity, with survival rates exceeding 80%.

[0071] 3. The compounds of this invention exhibit better tumor resistance reversal activity. Compared with saponin PPD and parent compounds 6 and 7, the PPD ring-opening epoxy-substituted derivatives of this invention have better tumor resistance reversal ability and activity in inhibiting P-glycoprotein function. For example, the clinically commonly used drug paclitaxel has no cytotoxicity to the tumor-resistant cell line KBV at 100 nM. When combined with 10 μM concentration of PPD ring-opening epoxy-substituted derivatives, the survival rate of KBV cells is significantly reduced, indicating that their sensitivity to paclitaxel-resistant tumor cells KBV is significantly increased, i.e., demonstrating tumor resistance reversal activity. Moreover, compared with PPD derivatives 6a-6b and 7a-7h without covalent cross-linking groups, PPD ring-opening epoxy-substituted derivatives 8a-8b and 9a-9h, which form covalent cross-linking groups through epoxy ring formation, have better tumor resistance reversal activity. Among them, the preferred compounds 8a, 8b, 9c, 9d, 9e, and 9f have significantly better tumor resistance reversal activity than the positive control drug verapamil (Vrp). The PPD ring-opening epoxy-substituted derivatives of this invention have strong development and application value. Detailed Implementation

[0072] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited to these embodiments.

[0073] Example 1: (20S,24R)-epoxy-3,4-open-ring-3-(2-thienylmethylamine-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 8a);

[0074] Using protopanaxadiol (20S-PPD) (200 mg, 0.534 mmol) as a starting material, it was dissolved in anhydrous dichloromethane (17 mL). An oxidative cyclization reaction was carried out using m-CPBA (109.866 mg, 0.736 mmol). After stirring at room temperature for 12 h, the solution was filtered, concentrated under vacuum, and then subjected to silica gel column chromatography (SGCC) to obtain intermediates 1 and 2. Intermediate 1 (82.0 mg, 0.172 mmol) was dissolved in anhydrous dichloromethane (2 mL), and pyridine chlorochromate (39.0 mg, 0.180 mmol) was added. After stirring at room temperature for 3 h, the solution was filtered, concentrated under vacuum, and then subjected to silica gel column chromatography (SGCC) to obtain intermediate 3. Intermediate 3 (130 mg, 0.27 mmol) was dissolved in 6 mL of dichloromethane, and m-CPBA (200 mg, 0.976 mmol) was added. The mixture was stirred overnight at room temperature, filtered, concentrated under vacuum, and then subjected to silica gel column chromatography (SGCC) to obtain intermediate 4. Intermediate 4 (220 mg, 0.45 mmol) was dissolved in 9 mL of anhydrous dichloromethane, and P-TSA (341.0 mg, 1.795 mmol) was added. The mixture was stirred at room temperature for 12 h, filtered, concentrated under vacuum, and then subjected to silica gel column chromatography (SGCC) to obtain intermediate 5. Intermediate product 5 (25 mg, 0.051 mmol) and 2-thiophene methylamine (0.061 mmol) were dissolved in anhydrous DCM (1 mL), HBTU (24 mg, 0.076 mmol) and 1 drop of Et3N were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA, and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate product 6a. Intermediate product 6a (30.0 mg) was dissolved in anhydrous DCM (4 mL), and NaHCO3 (33.0 mg, 0.409 mmol) was added. Then, m-CPBA (11.4 mg, 0.066 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with NaSO4, concentrated, and obtained by column chromatography to the target compound 8a [(20S,24R)-epoxy-3,4-open-ring-3-(2-thiophenemethylamine-1-yl)carbonyl-4(28)-epoxyethylene-dammarane-12β,25-diol].

[0075] 1H NMR (400MHz, CDCl3) δ7.22 (dd, J=4.9, 1.5Hz, 1H), 6.96 (tt, J=5.0, 2.4Hz, 2H) ,4.59(qt,J=15.2,7.8Hz,2H),3.85(dd,J=8.7,6.7Hz,1H),3.49(td,J=10.5, 4.4Hz,1H),2.96(d,J=4.1Hz,1H),2.75(d,J=4.0Hz,1H),2.22-1.31(m,22H), 1.27(s,6H),1.26(s,3H),1.10(s,3H),1.01(s,3H),0.96(s,3H),0.84(s,3H).

[0076] Example 2: (20S,24R)-epoxy-3,4-open-ring-3-(3-N-Boc-azacyclobutaneamine-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 8b);

[0077] Under argon protection, intermediate 5 (250 mg, 0.510 mmol) from Example 1 and 3-N-Boc-acetidine (0.612 mmol) were dissolved in anhydrous DCM (10 mL). HBTU (240 mg, 0.76 mmol) and Et3N (150 μL) were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate 6b. Intermediate 6b (300 mg) was dissolved in anhydrous DCM (40 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with Na2SO4, concentrated, and obtained by column chromatography to the target compound 8b [(20S,24R)-epoxy-3,4-open-ring-3-(3-N-Boc-azacyclobutaneamine-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol].

[0078] 1H NMR (400MHz, CDCl3) δ4.59 (qt, J=7.6, 5.4Hz, 1H), 4.25-4.19 (m, 2H), 3.86 (dt, J=8. 8,6.2Hz,1H),3.77-3.71(m,2H),3.51(tt,J=10.9,5.5Hz,1H),2.97-2.88(m,1H),2. 74(t,J=3.7Hz,1H),2.19(ddd,J=11.0,9.1,3.7Hz,1H),2.11-1.46(m,21H),1.44(s ,9H),1.28(s,6H),1.26(s,3H),1.11(s,3H),1.01(s,3H),0.95(s,3H),0.86(s,3H).

[0079] Example 3: (20S,24R)-epoxy-3,4-open-ring-3-(4-methylpiperidinol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9a);

[0080] Under argon protection, intermediate 5 (250 mg, 0.510 mmol) from Example 1 and 4-methylpiperidinol (0.612 mmol) were dissolved in anhydrous DCM (10 mL), EDCI (250 mg, 1.31 mmol) and DMAP (10 mg, 0.08 mmol), and stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA, and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate 7a. Intermediate 7a (300 mg) was dissolved in anhydrous DCM (20 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with NaSO4, concentrated, and obtained by column chromatography to the target compound 9a [(20S,24R)-epoxy-3,4-open-ring-3-(4-methylpiperidinol-1-yl)carbonyl-4(28)-epoxyethylene-dammarane-12β,25-diol].

[0081] 1H NMR (400MHz, CDCl3) δ4.82(td,J=10.2,5.0Hz,1H),3.86(dd,J=8.6,6.7Hz,1H),3.52(td,J=10.4,4.3Hz,1H),3.30(td,J=12.1,3.0Hz,2H ),2.69(t,J=3.3Hz,1H),2.56-1.28(m,29H),2.01(s,3H),1.27(s,6H),1.26(s,3H),1.10(s,3H),1.01(s,3H),0.97(s,3H),0.88(s,3H).

[0082] Example 4: (20S,24R)-epoxy-3,4-open-ring-3-(furfuryl-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9b);

[0083] Under argon protection, intermediate 5 (250 mg, 0.510 mmol) from Example 1 and furfuryl alcohol (0.612 mmol) were dissolved in anhydrous DCM (10 mL). EDCI (250 mg, 1.31 mmol) and DMAP (10 mg, 0.08 mmol) were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate 7b. Intermediate 7b (300 mg) was dissolved in anhydrous DCM (20 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with NaSO4, concentrated, and obtained by column chromatography as the target compound 9b [(20S,24R)-epoxy-3,4-open-ring-3-(furfuryl-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol].

[0084] 1H NMR(400MHz, CDCl3)δ7.43(d,J=1.9Hz,1H),6.43-6.32(m,2H),5.11-4.98(m,2 H),3.85(dd,J=8.7,6.7Hz,1H),3.49(td,J=10.5,4.4Hz,1H),2.72(d,J=4.2Hz, 1H),2.66(d,J=4.1Hz,1H),2.23-2.13(m,3H),2.11-1.28(m,19H),1.28(s,3H) ,1.26(s,3H),1.26(s,3H),1.10(s,3H),1.00(s,3H),0.96(s,3H),0.84(s,3H).

[0085] Example 5: (20S,24R)-epoxy-3,4-open-ring-3-(2-thiazol-methanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9c);

[0086] Under argon protection, intermediate 5 (250 mg, 0.510 mmol) from Example 1 and 2-thiazolyl methanol (0.612 mmol) were dissolved in anhydrous DCM (10 mL). EDCI (250 mg, 1.31 mmol) and DMAP (10 mg, 0.08 mmol) were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate 7c. Intermediate 7c (300 mg) was dissolved in anhydrous DCM (20 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with NaSO4, concentrated, and obtained by column chromatography the target compound 9c[(20S,24R)-epoxy-3,4-open-ring-3-(2-thiazol-methanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol].

[0087] 1H NMR (400MHz, CDCl3) δ7.80 (d, J = 3.2Hz, 1H), 7.41-7.33 (m, 1H), 5.47-5.32 (m, 2H) ,3.86(dd,J=8.7,6.7Hz,1H),3.50(td,J=10.4,4.4Hz,1H),2.76-2.65(m,2H),2.3 1-2.23(m,2H),2.19(ddd,J=11.1,9.2,3.8Hz,1H),2.11-1.12(m,19H),1.28(s,3 H),1.27(s,3H),1.26(s,3H),1.10(s,3H),1.01(s,3H),0.97(s,3H),0.86(s,3H).

[0088] Example 6: (20S,24R)-epoxy-3,4-open-ring-3-(2-thiophenamethanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9d);

[0089] Under argon protection, intermediate product 5 (250 mg, 0.510 mmol) from Example 1 and 2-thiophene methanol (0.612 mmol) were dissolved in anhydrous DCM (10 mL). EDCI (250 mg, 1.31 mmol) and DMAP (10 mg, 0.08 mmol) were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate product 7d. Intermediate product 7d (300 mg) was dissolved in anhydrous DCM (20 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. After drying with NaSO4 and concentration, the target compound 9d[(20S,24R)-epoxy-3,4-open-ring-3-(2-thiophene-methanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol] was obtained by column chromatography.

[0090] 1H NMR (400MHz, CDCl3) δ7.32(dd,J=5.1,1.3Hz,1H),7.09(dd,J=3.5,1.1Hz,1H),6.99(dd,J =5.1,3.5Hz,1H),5.32–5.19(m,2H),3.85(dd,J=8.7,6.7Hz,1H),3.49(td,J=10.5,4.5Hz ,1H),2.75-2.69(m,1H),2.65(d,J=4.2Hz,1H),2.23-2.11(m,3H),2.11-1.13(m,19H),1. 28(s,3H),1.26(s,3H),1.25(s,3H),1.10(s,3H),1.00(s,3H),0.96(s,3H),0.84(s,3H).

[0091] Example 7: (20S,24R)-epoxy-3,4-open-ring-3-(3-N-Boc-azacyclobutanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9e);

[0092] Under argon protection, intermediate 5 (250 mg, 0.510 mmol) from Example 1 and 3-N-Boc-azacyclobutanol (0.612 mmol) were dissolved in anhydrous DCM (10 mL). EDCI (250 mg, 1.31 mmol) and DMAP (10 mg, 0.08 mmol) were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate 7e. Intermediate 7e (300 mg) was dissolved in anhydrous DCM (20 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with NaSO4, concentrated, and obtained by column chromatography the target compound 9e[(20S,24R)-epoxy-3,4-open-ring-3-(3-N-Boc-azacyclobutanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol].

[0093] 1H NMR (400MHz, CDCl3) δ5.11 (tt, J=6.8, 4.2Hz, 1H), 4.23 (ddt, J=10.0, 6.8, 1.1H z,2H),3.92-3.87(m,1H),3.87-3.82(m,2H),3.52(td,J=10.5,4.4Hz,1H),2.76 -2.67(m,2H),2.25-2.15(m,3H),2.12-1.29(m,19H),1.45(s,9H),1.28(s,3H) ,1.27(s,3H),1.27(s,3H),1.10(s,3H),1.02(s,3H),0.97(s,3H),0.87(s,3H).

[0094] Example 8: (20S,24R)-epoxy-3,4-open-ring-3-(4-N-Boc-piperidinol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9f);

[0095] Under argon protection, intermediate 5 (250 mg, 0.510 mmol) from Example 1 and 4-N-Boc-piperidinol (0.612 mmol) were dissolved in anhydrous DCM (10 mL). EDCI (250 mg, 1.31 mmol) and DMAP (10 mg, 0.08 mmol) were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate 7f. Intermediate 7f (300 mg) was dissolved in anhydrous DCM (20 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with NaSO4, concentrated, and obtained by column chromatography the target compound 9f[(20S,24R)-epoxy-3,4-open-ring-3-(4-N-Boc-piperidinol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol].

[0096] 1H NMR(400MHz, CDCl3) δ4.82(tt,J=8.3,3.9Hz,1H),3.83-3.75(m,1H),3.70(d,J =11.5Hz,2H),3.45(td,J=10.5,4.4Hz,1H),3.09(ddd,J=13.1,9.1,3.4Hz,2H) ,2.69(d,J=4.3Hz,1H),2.61(d,J=4.4Hz,1H),2.18-0.96(m,26H),1.40(s,9H) ,1.21(s,3H),1.20(s,6H),1.03(s,3H),0.94(s,3H),0.90(s,3H),0.80(s,3H).

[0097] Example 9: (20S,24R)-epoxy-3,4-open-ring-3-(3-oxacyclobutanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9g);

[0098] Under argon protection, intermediate product 5 (250 mg, 0.510 mmol) from Example 1 and 3-oxetanebutanol (0.612 mmol) were dissolved in anhydrous DCM (10 mL). EDCI (250 mg, 1.31 mmol) and DMAP (10 mg, 0.08 mmol) were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate product 7 g. 7 g (300 mg) of intermediate product was dissolved in anhydrous DCM (20 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with NaSO4, concentrated, and obtained by column chromatography 9g of the target compound [(20S,24R)-epoxy-3,4-open-ring-3-(3-oxacyclobutanol-1-yl)carbonyl-4(28)-epoxyethylene-dammarane-12β,25-diol].

[0099] 1H NMR (400MHz, CDCl3) δ5.43(tt,J=6.5,5.3Hz,1H),4.92-4.82(m,2H),4.69-4.59(m,2H),3.86(dd,J=8.7,6.7Hz,1H),3.52(td,J=10.6,4.5Hz, 1H),2.77-2.67(m,2H),2.26-2.15(m,3H),2.13-1.29(m,19H),1.28(s ,3H),1.27(s,6H),1.10(s,3H),1.02(s,3H),0.97(s,3H),0.88(s,3H).

[0100] Example 10: (20S,24R)-epoxy-3,4-open-ring-3-(2-pyridinylmethanol-1-yl)carbonyl-4(28)-epoxy-dammarane-12β,25-diol (compound 9h);

[0101] Under argon protection, intermediate product 5 (250 mg, 0.510 mmol) from Example 1 and 2-pyridinemethanol (0.612 mmol) were dissolved in anhydrous DCM (10 mL). EDCI (250 mg, 1.31 mmol) and DMAP (10 mg, 0.08 mmol) were added, and the mixture was stirred at room temperature for 10 min. Then, an appropriate amount of deionized water was added for quenching. The organic layer was extracted with EA and washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution. The mixture was then dried over Na2SO4, concentrated, and subjected to column chromatography to obtain intermediate product 7h. Intermediate product 7h (300 mg) was dissolved in anhydrous DCM (20 mL), and NaHCO3 (330 mg, 4.086 mmol) was added. Then, m-CPBA (114.3 mg, 0.663 mmol) was slowly added, and the mixture was stirred at room temperature for 2 h. Subsequently, an appropriate amount of deionized water was added for quenching, the organic layer was extracted with EA, and the organic layer was washed successively with saturated NaHCO3 solution and saturated NaCl aqueous solution, then dried with NaSO4, concentrated, and obtained by column chromatography as the target compound 9h[(20S,24R)-epoxy-3,4-open-ring-3-(2-pyridinylmethanol-1-yl)carbonyl-4(28)-epoxyethylene-dammarane-12β,25-diol].

[0102] 1H NMR (400MHz, CDCl3) δ8.30(dd,J=6.3,1.3Hz,1H),7.40(d,J=2.2Hz,1H),7.34(ddt,J=7.8,6.1,1.3Hz,1H),5.39(s,2H),3.86(dd,J=8.7,6.7Hz,1H) ,3.53(td,J=10.5,4.4Hz,1H),2.76-2.67(m,2H),2.41-1.28(m,22H),1.2 7(s,6H),1.25(s,3H),1.10(s,3H),1.02(s,3H),0.99(s,3H),0.88(s,3H).

[0103] Example 11: Cytotoxicity evaluation of PPD derivatives

[0104] Experimental methods:

[0105] (1) Cell plating: KBV cells in logarithmic growth phase and in good condition were digested and counted, according to a 2.5×10⁻⁶ m² / h²· ... 3 / wells were seeded into 96-well plates and cultured in a 37°C, 5% CO2 cell incubator;

[0106] (2) Cell drug administration: After cells adhered to the plate for 24 hours, 30 μM of different derivatives and corresponding solvents were added for culture, with 3 parallel replicates for each group. After drug administration, the 96-well plate was placed in an incubator and cultured for another 72 hours.

[0107] (3) MTT assay: After culturing cells with the appropriate drug for 72 hours, add 30 μL of 5 mg / mL MTT solution and continue culturing at 37℃ for 2–4 hours. Discard the supernatant, taking care not to disrupt the crystals formed at the bottom of the wells. Add 150 μL of DMSO to each well and shake on a shaker in the dark for about 10 minutes to fully dissolve the formazan crystals. Finally, use an ELISA reader to detect the absorbance at a wavelength of 570 nm. The tumor cell group treated with DMSO was used as the control group, and verapamil was used as the positive control. The inhibition rate of the derivative was calculated. Inhibition rate (%) = (average OD value of the control group – average OD value of the drug group) / average value of the control group × 100%

[0108] Experimental results: At a drug concentration of 30 μM, the survival rate of drug-resistant tumor cells KBV treated with Vrp was approximately 40%, while the survival rate of drug-resistant tumor cells KBV treated with compounds 8a-8b and 9a-9h was over 80%, indicating that the cytotoxicity of these compounds was significantly lower than that of Vrp.

[0109] Table 1. Evaluation results of the cytotoxicity of PPD derivatives against KBV cells.

[0110]

[0111] Example 12: Evaluation of the antitumor MDR activity of PPD derivatives

[0112] Experimental methods:

[0113] (1) Cell plating: KBV cells in logarithmic growth phase and in good condition were digested and counted, according to a 2.5×10⁻⁶ m² / h²· ... 3 / wells were seeded into 96-well plates and cultured in a 37°C, 5% CO2 cell incubator;

[0114] (2) Cell drug administration: After cells adhered to the plate for 24 hours, 10 μM of different derivatives were added, along with 100 nM paclitaxel and DMSO as controls. Each group was divided into 3 replicates. After drug administration, the 96-well plate was placed in an incubator and cultured for another 72 hours.

[0115] (3) MTT assay: After culturing cells with the appropriate drug for 72 hours, add 30 μL of 5 mg / mL MTT solution and continue culturing at 37℃ for 2–4 hours. Discard the supernatant, taking care not to disrupt the crystals formed at the bottom of the wells. Add 150 μL of DMSO to each well and shake on a shaker in the dark for about 10 minutes to fully dissolve the formazan crystals. Finally, use an ELISA reader to detect the absorbance at a wavelength of 570 nm. The tumor cell group treated with DMSO was used as the control group, and verapamil was used as the positive control. The inhibition rate of the derivative was calculated. Inhibition rate (%) = (average OD value of the control group – average OD value of the drug group) / average value of the control group × 100%

[0116] Experimental Results: Paclitaxel showed no cytotoxicity to the KBV tumor cell line at 100 nM. However, the combined addition of 10 μM PPD derivatives significantly reduced KBV cell survival, indicating a markedly enhanced sensitivity of KBV to paclitaxel, demonstrating a tumor resistance reversal effect. Furthermore, compared to PPD derivatives 6a-6b and 7a-7h without covalent cross-linking groups, PPD derivatives 8a-8b and 9a-9h, which formed covalent cross-linking groups through epoxide cyclization, exhibited better tumor resistance reversal activity. Among these, the preferred compounds 8a, 8b, 9c, 9d, 9e, and 9f showed significantly better tumor resistance reversal activity than the positive control drug verapamil (Vrp).

[0117] Table 2 Evaluation results of the antitumor MDR activity of PPD derivatives against KBV cells

[0118]

[0119]

[0120] The above description is only a partial embodiment of this application and an explanation of the technical principles used.

[0121] Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the combination of the above-described technical features, but should also cover other technical solutions formed by any combination of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with, but not limited to, technical features with similar functions disclosed in this application.

Claims

1. A PPD open ring epoxy substituted derivative represented by Formula 8 or Formula 9, or a pharmaceutically acceptable salt of a compound represented by Formula 8 or Formula 9. wherein R1, R2are each independently R x -K-, wherein K represents methylene or is absent, R x is unsubstituted or substituted with one or more substituents selected from the group consisting of pyrazine, pyridine, azetidine, thiophene, piperidine, furan, tetrahydrofuran, thiazole; said substituents being C1-C10 alkyl or tert-butyloxycarbonyl.

2. The PPD open ring epoxy-substituted derivative according to claim 1, wherein R1 represents 1-methyl-(2-thiophen)-1-yl or 3-N-Boc-azetidin-1-yl; R2 represents 4-methylpiperidin-1-yl, 1-methyl-(2-furan)-1-yl, 1-methyl-(2-thiazol)-1-yl, 1-methyl-(2-thiophen)-1-yl, 3-N-Boc-azetidin-1-yl, 4-N-Boc-piperidin-1-yl, 3-oxetan-1-yl, or 1-methyl-(2-pyridin)-1-yl.

3. The PPD open ring epoxy substituted derivative of claim 1, wherein The PPD open ring epoxy substituted derivative is one of the following compounds:

4. The method for preparing the PPD ring-opening epoxy-substituted derivative as described in claim 1, characterized in that, The method is shown in the following reaction formula:

5. Use of the PPD open ring epoxy substituted derivative and pharmaceutically acceptable salt thereof according to any one of claims 1 to 3 in the preparation of a tumor drug resistance reversal agent / tumor drug sensitizer, or a tumor drug resistance reversal agent / tumor drug sensitizer comprising a pharmaceutically acceptable carrier.

6. The use according to claim 5, wherein The PPD open ring epoxy substituted derivative and pharmaceutically acceptable salt thereof are used in the preparation of a tumor drug resistance reversal agent / tumor drug sensitizer for overcoming P-glycoprotein-mediated tumor drug resistance, or a tumor drug resistance reversal agent / tumor drug sensitizer comprising a pharmaceutically acceptable carrier.

7. Use of the PPD open ring epoxy substituted derivative and pharmaceutically acceptable salt thereof according to any one of claims 1 to 3 in the preparation of an antitumor drug, wherein the antitumor drug comprises a clinical antitumor drug and a tumor drug resistance reversal agent / tumor drug sensitizer, and the tumor drug resistance reversal agent / tumor drug sensitizer is a PPD open ring epoxy substituted derivative represented by Formula 8 or Formula 9 and a pharmaceutically acceptable salt thereof.

8. Use according to claim 7, wherein The tumor is breast cancer, colon cancer, cervical cancer, liver cancer, gastric cancer, or lung cancer. The clinical antitumor drug is paclitaxel.

9. A multidrug resistance reversal pharmaceutical composition comprising the PPD open ring epoxy substituted derivative and pharmaceutically acceptable salt thereof according to any one of claims 1 to 3.

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