Picrasma quassioides bitter principle compound in brucea javanica fruits as well as preparation method and insecticidal application thereof

Abstract

The invention relates to picrasma quassioides bitter principle compounds in brucea javanica as well as a preparation method and application thereof, belongs to the technical field of natural medicinal chemistry, and in particular relates to two picrasma quassioides bitter principle compounds extracted and separated from Brucea javanica fruit (Brucea javica) of a picraliaceae brucea plant and a biomimetic synthesis method of the compound 1, and the compounds have good insecticidal activity. In addition, the preparation method disclosed by the invention is simple and easy to implement, relatively good in reproducibility and relatively high in purity. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the technical field of natural medicine chemistry, and particularly relates to novel skeleton quassinoid compounds prepared from the fruits of the plant Brucea javanica, a preparation method thereof, and applications of these compounds in the preparation of pesticides. Background Art

[0002] Brucea javanica is a plant of the genus Brucea in the family Simaroubaceae. Its fruits and leaves can be used as medicine, with the effects of clearing heat and drying dampness, killing insects, detoxifying, stopping dysentery, and stopping malaria. It can be used to treat diseases such as amoebic dysentery and malaria. Topically, it has a corrosive effect and is used for verrucae, corns, etc. Modern phytochemical and pharmacological studies have shown that Brucea javanica contains active ingredients such as quassinoids, alkaloids, and triterpenes, and has various activities such as anti-tumor, insecticidal, antiviral and anti-inflammatory, and antioxidant activities. Summary of the Invention

[0003] The purpose of the present invention is to provide a novel skeleton quassinoid compound prepared from the fruits of Brucea javanica, a preparation method thereof, biomimetic synthesis, and its application in insecticidal aspects.

[0004] Structures of two novel skeleton quassinoid compounds isolated from the fruits of Brucea javanica, a plant of the genus Brucea in the family Simaroubaceae, are shown in the figure:

[0005]

[0006] The preparation technical solution of the present invention includes the following steps:

[0007] Take dry fruits of Brucea javanica and extract them with ethanol. Combine the extraction solutions and concentrate to obtain an extract. The extract is extracted with dichloromethane and n-butanol, and the obtained components are subjected to silica gel column chromatography and isocratic gradient elution with a dichloromethane-methanol system of 100:1 - 1:1, and a total of 6 components Fr.A - F are collected;

[0008] Use HP20 and ODS column chromatography to gradient elute component Fr.B with an ethanol-water system of 20:80 - 90:10 to obtain 6 components Fr.B1 - B6;

[0009] Compound 1 - 2 was obtained by eluting with a petroleum ether-ethyl acetate system of 100:1 - 10:1 through silica gel column chromatography and separating Fr.B4 using a mobile phase of acetonitrile-water on preparative reverse-phase high-performance liquid chromatography.

[0010] Preferably, the preparation method of the quassinoid compounds in Brucea javanica fruits uses the dry fruits of Brucea javanica, a plant of the genus Brucea in the Simaroubaceae family.

[0011] Preferably, for the preparation method of the quassinoid compounds in Brucea javanica fruits, take the dry Brucea javanica fruits and reflux extract them 3 times with 70 - 80% industrial ethanol, each time for 2 - 3 h.

[0012] Preferably, for the preparation method of the quassinoid compounds in Brucea javanica fruits, separate Fr.B4 with an acetonitrile - water mobile phase of 50:50 - 20:80.

[0013] The present invention also provides a biomimetic synthesis method of quassinoid compound 1 in Brucea javanica fruits. The biomimetic synthesis method is to rapidly synthesize compound 1 through a one - step vinylogous Akdol aldol condensation reaction using bruceantinol, which is abundant in Brucea javanica, as a precursor.

[0014] Preferably, the biomimetic synthesis method includes the following steps:

[0015] Dissolve bruceantinol in DMF, the reaction conditions are 0 - 20 °C, the catalyst is sodium hydroxide or potassium hydroxide, the reaction time is 24 - 36 h. After the reaction is complete, quench it with 10% HCl, extract with ethyl acetate, combine the organic phases and concentrate under reduced pressure, and then separate on a preparative reversed - phase high - performance liquid chromatography using an acetonitrile - water mobile phase to obtain compound 1.

[0016] The obtained compounds were identified by systematic structure determination as follows:

[0017] The structures of compounds 1 - 2 were identified by high - resolution mass spectrometry, one - dimensional NMR, two - dimensional NMR, computational NMR, computational ECD and X - single crystal diffraction methods. The corresponding structure characterization data are shown in Table 1, and the spectra are as Figures 1-15 shown.

[0018] Bruquass A(1): white amorphous powder; Determine the molecular formula as C + (cacld for C 31 H 41 O 12 , 605.2593) through HRESIMS m / z 605.2590[M + H] 31 H 41 O 12 ; By analyzing the 1 HNMR of bruquass A, 13The structures of bruquass A were determined by \(^{13}\)CNMR, HSQC, HMBC and ECD spectra, and it was a new compound.

[0019] Bruquass B (2): white amorphous powder; The molecular formula was determined to be \(C_{30}H_{38}O_{6}\) by HRESIMS m / z 607.2745 [M + H]\(^{+}\) + (calcd for \(C_{30}\) 31 H 43 O 12 , 607.2749); The structure of bruquass B was determined by analyzing the \(^{1}\)H NMR, 31 H 43 O 12 \(^{13}\)CNMR, HSQC, HMBC and ECD spectra of bruquass B, and it was a new compound. 1 \(^{1}\)H NMR, 13 \(^{13}\)CNMR, HSQC, HMBC and ECD spectra of bruquass B, and it was a new compound.

[0020] The present invention also provides a pharmaceutical composition comprising the quassinoid compound prepared from Brucea javanica or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or excipient.

[0021] The present invention also provides the use of the quassinoid compound prepared from Brucea javanica fruits or a pharmaceutically acceptable salt thereof or the pharmaceutical composition comprising the above compound in the preparation of pesticides.

[0022] The insecticidal activities of the two new skeleton compounds of the present invention were investigated. Compound 1 showed good antifeedant activity against Plutella xylostella. Therefore, compound 1 of the present invention has the prospect of further development as a pesticide.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The advantages of the present invention are that the compounds are all new compounds with novel structures and are optically pure compounds with determined stereoconfigurations. At the same time, they have good insecticidal activities and have the value of further development.

[0025] Table 1 NMR data of compounds 1 and 2 (DMSO-d 6 )

[0026] BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 : HRESIMS spectrum of compound 1;

[0028] Figure 2 : 1 \(^{1}\)H NMR spectrum of compound 1;

[0029] Figure 3 : The 13 C-NMR spectrum of Compound 1;

[0030] Figure 4 : The HSQC spectrum of Compound 1;

[0031] Figure 5 : The HMBC spectrum of Compound 1;

[0032] Figure 6 : The 1 H- 1 H COSY spectrum of Compound 1;

[0033] Figure 7 : The NOESY spectrum of Compound 1;

[0034] Figure 8 : The HRESIMS spectrum of Compound 2;

[0035] Figure 9 : The 1 H NMR spectrum of Compound 2;

[0036] Figure 10 : The 13 C-NMR spectrum of Compound 2;

[0037] Figure 11 : The HSQC spectrum of Compound 2;

[0038] Figure 12 : The HMBC spectrum of Compound 2;

[0039] Figure 13 : The 1 H- 1 H COSY spectrum of Compound 2;

[0040] Figure 14 : The NOESY spectrum of Compound 2;

[0041] Figure 15 : The key HMBC, 1 H- 1 H COSY, NOESY related and calculated ECD spectra of Compound 1 and Compound 2. Detailed implementation mode

[0042] The following listed examples are helpful for those skilled in the art to better understand the present invention, but do not limit the present invention in any way.

[0043] Example 1: Preparation of Compound 1-2

[0044] Take dry Brucea javanica fruits and extract them with ethanol. Combine the extraction solutions and concentrate to obtain an extract. The extract is extracted with dichloromethane and n-butanol, and the obtained components are separated by silica gel column chromatography with an isocratic gradient elution using dichloromethanol systems of 100:1, 50:1, 30:1, 10:1, 5:1, and 1:1, and a total of 6 components, Fr.A - F, are collected.

[0045] Use HP20 and ODS column chromatography to gradient elute component Fr.B with ethanol - water systems of 20:80, 40:60, 60:40, 80:20, and 90:10 to obtain 6 components, Fr.B1 - B6.

[0046] Elute through silica gel column chromatography with petroleum ether - ethyl acetate systems of 100:1, 50:1, 30:1, 20:1, and 10:1, and use a mobile phase of acetonitrile - water on preparative reversed - phase high - performance liquid chromatography to separate Fr.B4 to obtain compounds 1 - 2.

[0047] Example 2: Bionic synthesis of compound 1

[0048] Biogenetically, compound 1 is derived from bruceolide and isovaleraldehyde through an aldol condensation reaction with vinylogous structure. Based on this, dissolve bruceolide (50 mg, 0.10 mmol) in DMF, and successively add isovaleraldehyde (11 μl, 0.12 mmol, 1.2 equiv.), sodium hydroxide (0.78 mg, 0.02 mmol, 0.2 equiv.), react at 0 - 20 °C for 24 - 36 hours. After the reaction is completed, quench with 10% hydrochloric acid, then extract three times with ethyl acetate. Combine the organic phases and evaporate the solvent to dryness under reduced pressure, and separate by high - performance liquid chromatography to obtain the target product 1, with a yield of approximately 16.9 - 25.3%.

[0049] Example 3: Investigation of the antifeedant activity of compounds 1 - 2

[0050] Prepare a 200 μg / mL medicinal solution. Use a punch to cut out leaf discs with a diameter of 7 mm from the feeding leaves corresponding to the test insects. Immerse the leaf discs in the medicinal solution at different concentrations for 10 - 20 s, drain the excess medicinal solution, and then spread them horizontally on a 9 cm petri dish with a moisturizing filter paper and air - dry naturally until the surface is free of water. Introduce a certain number of test insects into each well, repeat each medicinal solution concentration 3 times, seal with plastic wrap and punch holes for ventilation. Use the drug solvent as the negative control and the commercial insecticide fipronil as the positive control. Place the petri dishes in an incubator: temperature 26 ± 0.5 °C, relative humidity 50%, light cycle L:D of 16 h:24 h. After 48 h, observe and record the number of dead test insects. Consider a test insect with no response when gently touched with a writing brush as dead, record the number of dead test insects, the number of surviving test insects, and the death date, and calculate the mortality rate and corrected mortality rate:

[0051] Mortality rate = (Number of dead insects / Total number of insects in the treatment) × 100%;

[0052] Corrected mortality rate = (Treatment mortality rate - Control mortality rate) / (1 - Control mortality rate) × 100%.

[0053] Table 2 Insecticidal activity of Compounds 1 - 2 against Plutella xylostella

[0054]

[0055] The experimental results are shown in Table 2. The experimental results indicate that Compound 1 exhibits good insecticidal activity against Plutella xylostella at a concentration of 200 μg / mL. Therefore, Compound 1 described in the present invention has the prospect of further development as an insecticide.

[0056] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A quasin compound in Brucea javanica fruit, characterized in that: The compound is any one of the structures shown below:

2. The quassin compounds in Brucea javanica fruit according to claim 1, characterized in that: The brucea javanica is a plant of the genus Brucea in the family Simiaceae.

3. The method for preparing the quasin compounds in Brucea javanica fruit according to claim 1 or claim 2, characterized in that: The steps include: The dried Brucea javanica fruit was extracted with ethanol, and the combined extracts were concentrated to obtain an extract, which was extracted with dichloromethane and n-butanol, and the obtained components were subjected to silica gel column chromatography, and isocratic gradient elution was performed with a dichloromethanol system of 100:1-1:1, and a total of 6 components Fr.AF were collected; Using HP20, ODS column chromatography, component Fr.B was gradient eluted with an ethanol-water system of 20:80-90:10 to obtain 6 components Fr.B1-B6; Compound 1-2 was obtained by separating Fr.B4 using silica gel column chromatography with a petroleum ether-ethyl acetate system of 100:1-10:1 and preparative reverse phase high performance liquid chromatography using an acetonitrile-water mobile phase.

4. The method for preparing quasin compounds in Brucea javanica fruit according to claim 3, characterized in that: Take the dried Brucea javanica fruit and reflux extract it with 70-80% industrial ethanol for 3 times, each time for 2-3 hours.

5. The method for preparing quasin compounds in Brucea javanica fruit according to claim 3, characterized in that: Fr.B4 was separated with acetonitrile-water mobile phase ranging from 50:50 to 20:

80.

6. A method for preparing the quasin compounds in the fruit of Brucea javanica according to claim 1 or claim 2, characterized in that: The compound is compound 1, and the preparation method is to quickly synthesize compound 1 through a one-step vinylogous Akdol aldol condensation reaction, using bruceiol, which is abundant in brucei, as a precursor.

7. The preparation method according to claim 6, characterized in that: The following steps are involved: Brucea bruceiol was dissolved in DMF, the reaction conditions were 0-20°C, the catalyst was sodium hydroxide or potassium hydroxide, the reaction time was 24-36h, and after the reaction was complete, 10% HCl was used to quench, and after extraction with ethyl acetate, the organic phases were combined and concentrated under reduced pressure, and then separated on a preparative reverse-phase high performance liquid chromatography using acetonitrile-water as the mobile phase to obtain compound 1.

8. A pharmaceutical composition, characterized in that The pharmaceutical composition comprises the quasin compounds in the Brucea javanica fruit according to claim 1 or claim 2 or their pharmaceutically acceptable salts and a pharmaceutically acceptable carrier or excipient.

9. Use of the quasin compounds or pharmaceutically acceptable salts thereof in the fruit of Brucea javanica according to claim 1 or claim 2 in the preparation of insecticides.

10. Use of the pharmaceutical composition according to claim 8 in the preparation of insecticides.

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