Solid-phase synthesis method of antibacterial bakuchiol derivative

Abstract

The invention belongs to the technical field of biological medicines, and relates to synthesis of medicines, in particular to a solid-phase synthesis method of an antibacterial bakuchiol derivative. Coupling Fmoc-Arg (X)-OH on the solid-phase synthetic resin for three times to obtain Arg (X)-Arg (X)-Arg (X)-resin, namely tripeptide intermediate resin; coupling a compound 1 on the tripeptide intermediate resin to obtain bakuchiol derivative resin; cracking the bakuchiol derivative resin to obtain a bakuchiol derivative; in the coupling process of Fmoc-Arg (X)-OH and the coupling compound 1, at least two amide condensing agents are added at the same time during amide condensation. The solid-phase synthesis method provided by the invention has the advantages of low price and wide source of raw materials, fewer byproducts, simple operation, high yield and low cost, and is beneficial to industrial mass production, and the compound only needs to be purified once.

Description

Technical Field

[0001] The invention belongs to the technical field of biomedicine and relates to the synthesis of drugs, and specifically to a solid phase synthesis method of antibacterial bakuchiol derivatives. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Jiangxi Shimei Pharmaceutical Co., Ltd. disclosed a bakuchiol derivative in patent CN113896620A, which can be used as a new type of antibacterial drug with high efficiency and low toxicity and can effectively overcome drug resistance. The synthetic route of compound 58 is as follows:

[0004]

[0005] The inventors have found that the synthesis method of the above compound 58 has two problems: the first is that two high-cost and scarce raw materials H-Arg-Arg-OMe.2HCl and H-Arg-NH 2 .2HCI, which results in the sample production scale being largely limited by the raw materials. The second point is that the arginine side chain is not protected, which leads to more complicated side reactions during the synthesis process, thus affecting the product purity and yield, increasing the number of reverse preparation and purification, and increasing the cost. Summary of the invention

[0006] In view of the problems faced by the synthetic route of compound 58 reported in patent CN 113896620 A, such as expensive raw materials and scarce supply, limited industrial production, more reaction by-products due to exposed side chains of raw materials, low purity, and no obvious cost advantage, the purpose of the present invention is to provide a solid-phase synthesis method for antibacterial bakuchiol derivatives. The raw materials used in the solid-phase synthesis method provided by the present invention are cheap and widely available, with fewer by-products, only one purification of the compound is required, the operation is simple, the yield is high, the cost is low, and it is conducive to industrial mass production.

[0007] In order to achieve the above object, the technical solution of the present invention is:

[0008] A solid phase synthesis method for antibacterial bakuchiol derivatives comprises the following steps:

[0009] Fmoc-Arg(X)-OH was coupled three times on the solid phase synthetic resin to obtain

[0010] Arg(X)-Arg(X)-Arg(X)-resin, which is a tripeptide intermediate resin;

[0011] Compound 1 is coupled to the tripeptide intermediate resin to obtain a bakuchiol derivative resin;

[0012] cracking the bakuchiol derivative resin to obtain the bakuchiol derivative;

[0013] Among them, the chemical structural formula of compound 1 is:

[0014] The chemical structural formula of the bakuchiol derivative (i.e., compound 58) is:

[0015]

[0016] During the coupling of Fmoc-Arg(X)-OH and the coupling of compound 1, at least two amide condensation agents are added simultaneously during the amide condensation.

[0017] First, since arginine is difficult to couple, it is difficult to select arginine as a raw material to prepare bakuchiol derivatives (i.e., compound 58) by solid phase synthesis. Secondly, in order to prepare compound 58 by solid phase synthesis, the present invention first uses an amide condensing agent for activation, and only part of the arginine can be coupled with the resin. At this time, it is necessary to use acetic acid to cap the end, and then add an amide condensing agent for activation, and then couple. There are not only the problems of cumbersome steps and long time, but also the problems of more impurities generated and lower yield. The present invention unexpectedly found through experiments that during the amide condensation, adding at least two amide condensing agents at the same time can completely couple arginine with the resin, which not only solves the problems of cumbersome steps and long time, but also generates fewer impurities and higher yield. Thirdly, when the present invention performs subsequent coupling of compound 1, it is found that it has the same problem as arginine, so the method of adding at least two amide condensing agents at the same time solves the problems of cumbersome steps, long time, more impurities and lower yield of the subsequent coupling of compound 1.

[0018] In the present invention, the solid phase synthetic resin can be one of Rink resin, HMBA resin, HMPA resin, Sieber resin, Wang resin, Nitroveratryl resin, PAL resin, AMEBA resin, Oxime resin, SASRIN resin, and Dde resin. The present invention shows that when the solid phase synthetic resin is Rink resin, the synthetic effect is better.

[0019] In the present invention, the process of coupling Fmoc-Arg(X)-OH includes amide condensation and removal of the Fmoc protecting group. Specifically, the amide condensation agent used in the amide condensation in the coupling Fmoc-Arg(X)-OH is a combination of HOBt (1-hydroxybenzotriazole) / DIC (N,N'-diisopropylcarbodiimide) and HATU (2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate) / EDCI (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride), HOSu (N-hydroxysuccinimide) / EDC (1-ethyl-(3 The present invention discloses a combination of HOBT / DIC and HATU / EDCI, a combination of HONB (N-hydroxy-5-norbornene-2,3-dicarboximide) / DCC (dicyclohexylcarbodiimide) and HATU / EDCI, a combination of HOBt / DIC and HBTU (O-benzotriazole-tetramethyluronium hexafluorophosphate) / EDCI, a combination of HOSu / EDC and HBTU / EDCI, and a combination of HONB / DCC and HBTU / EDCI. The present invention shows that when the amide condensation agent is a combination of HOBT / DIC and HATU / EDCI, the efficiency of preparing the tripeptide intermediate resin is higher.

[0020] In the present invention, the coupling process of compound 1 includes amide condensation. Specifically, the amide condensation agent used in the amide condensation of coupling compound 1 is a combination of HOBt / DIC and HATU / EDCI, a combination of HOSu / EDC and HATU / EDCI, a combination of HONB / DCC and HATU / EDCI, a combination of HOBt / DIC and HBTU / EDCI, a combination of HOSu / EDC and HBTU / EDCI, and a combination of HONB / DCC and HBTU / EDCI. The present invention shows that when the amide condensation agent is a combination of HOBT / DIC and HATU / EDCI, the efficiency of preparing the bakuchiol derivative resin is higher.

[0021] The present invention shows that when the solid phase synthesis resin is Rink resin and the amide condensation agent of amide condensation is a combination of HOBT / DIC and HATU / EDCI, the efficiency in the solid phase synthesis process is higher and the side reactions are less.

[0022] In the present invention, X in Fmoc-Arg(X)-OH is a protecting group of the guanidine group or the side chain amino group of arginine (Arg), which can be Mtr (4-methoxy-2,3,6-trimethylbenzenesulfonyl), pbf (2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl), Adoc (adamantyloxycarbonyl), Pmc (9-benzyloxycarbonyl), Trt (trityl), Tos (p-toluenesulfonyl), etc.; Fmoc is a protecting group of arginine, and its Chinese name is N-fluorenylmethyloxycarbonyl. The present invention shows that when X in Fmoc-Arg(X)-OH is pbf, X can be removed simultaneously during the cleavage process, and the effect of removing X is better.

[0023] Specifically, its solid phase synthesis route is as follows:

[0024]

[0025] The beneficial effects of the present invention are:

[0026] (1) The present invention synthesizes bakuchiol derivatives (i.e., compound 58) by solid phase synthesis. Since compound 58 is a polypeptide analog, it can be regarded as a tetrapeptide compound. Its short peptide property overcomes a major drawback of solid phase synthesis, that is, the sample yield and purity decrease sharply as the peptide chain is extended, thereby increasing the sample yield from the original 63% to 86%.

[0027] (2) The present invention synthesizes compound 58 by solid phase synthesis, which reduces the number of purification times and only requires one step of purification to obtain a high-purity product, thereby improving the yield and being suitable for industrial production.

[0028] (3) The present invention uses a multi-protected arginine raw material with only one carboxyl group exposed, while the resin peptide has only one amino group exposed, thereby ensuring directional and site-specific synthesis, avoiding the appearance of by-products to the greatest extent, improving the purity of the crude sample, and facilitating the subsequent purification of the sample.

[0029] (4) The arginine raw material used in the present invention has a wide source, is cheap, and has two different protection groups for removal. The main chain amino group adopts an Fmoc protection group that can be removed by alkali, and the side chain amino group adopts an acid protection group. The side chain protection group can be removed together when the product is cleaved, which is simple to operate and saves cost and time.

[0030] (5) Although the arginine raw material used in the present invention is a well-known difficult amino acid, that is, an amino acid that is difficult to complete or completely complete coupling, in order to solve this problem, the present invention adopts a condensation method of two condensing agent combinations (especially a dual combination of HOBT / DIC and HATU / EDCI) (especially with Rink resin) to achieve 100% coupling of arginine, reduce the generation of impurities in the coupling process, and improve the purity of the crude sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0032] Figure 1 is the HPLC spectrum of compound 58 in Example 1 of the present invention;

[0033] Figure 2 It is the mass spectrum of compound 58 in Example 1 of the present invention. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0036] In view of the fact that the existing method for preparing bakuchiol derivatives (i.e., compound 58) has raw material limitations and produces a large number of reaction by-products, which affects its production cost, the present invention proposes a solid phase synthesis method for antibacterial bakuchiol derivatives.

[0037] A typical embodiment of the present invention provides a solid phase synthesis method of antibacterial bakuchiol derivatives, comprising the following steps:

[0038] Fmoc-Arg(X)-OH was coupled three times on the solid phase synthetic resin to obtain

[0039] Arg(X)-Arg(X)-Arg(X)-resin, which is a tripeptide intermediate resin;

[0040] Compound 1 is coupled to the tripeptide intermediate resin to obtain a bakuchiol derivative resin;

[0041] cracking the bakuchiol derivative resin to obtain the bakuchiol derivative;

[0042] Among them, the chemical structural formula of compound 1 is:

[0043] The chemical structural formula of the bakuchiol derivative (i.e., compound 58) is:

[0044]

[0045] During the coupling of Fmoc-Arg(X)-OH and the coupling of compound 1, at least two amide condensation agents are added simultaneously during the amide condensation.

[0046] In some embodiments, the solid phase synthetic resin is one of Rink resin, HMBA resin, HMPA resin, Sieber resin, Wang resin, Nitroveratryl resin, PAL resin, AMEBA resin, Oxime resin, SASRIN resin, and Dde resin, preferably Rink resin.

[0047] In some embodiments, the degree of substitution of the solid phase synthesis resin peptide is 0.7 to 1.2 mol / kg, preferably 1 mol / kg.

[0048] In some embodiments, the protecting group X in Fmoc-Arg(X)-OH is Mtr, pbf, Adoc, Pmc, Trt, Tos, NO 2 , Pme, Mts, preferably pbf (ie, Fmoc-Arg(pbf)-OH).

[0049] In some embodiments, the solvent used in the solid phase synthesis process is N,N-dimethylformamide, dichloromethane, tetrahydrofuran, preferably N,N-dimethylformamide.

[0050] In some embodiments, the process of coupling Fmoc-Arg(X)-OH includes amide condensation and removal of the Fmoc protecting group.

[0051] In some embodiments, during the coupling of Fmoc-Arg(X)-OH, the amide condensation agent used is a combination of HOBt / DIC and HATU / EDCI, a combination of HOSu / EDC and HATU / EDCI, a combination of HONB / DCC and HATU / EDCI, a combination of HOBt / DIC and HBTU / EDCI, a combination of HOSu / EDC and HBTU / EDCI, a combination of HONB / DCC and HBTU / EDCI, preferably a combination of HOBT / DIC and HATU / EDCI. The " / " in the present invention means that the reagent contains both the substances before and after the " / ", for example, HOBt / DIC means that HOBt and DIC are contained at the same time.

[0052] In some embodiments, during the coupling of Fmoc-Arg(X)-OH, the temperature of amide condensation is 20-40° C., and the time of amide condensation is 3-6 hours.

[0053] In some embodiments, during the coupling of Fmoc-Arg(X)-OH, the Fmoc protecting group is removed using a piperidine / N,N-dimethylformamide solution. Specifically, the input volume (ml) of the piperidine / N,N-dimethylformamide solution is 5 to 10 times the weight (g) of the solid phase synthetic resin.

[0054] In some embodiments, during the coupling process of compound 1, the amide condensing agent used is a combination of HOBt / DIC and HATU / EDCI, a combination of HOSu / EDC and HATU / EDCI, a combination of HONB / DCC and HATU / EDCI, a combination of HOBt / DIC and HBTU / EDCI, a combination of HOSu / EDC and HBTU / EDCI, a combination of HONB / DCC and HBTU / EDCI, preferably a combination of HOBT / DIC and HATU / EDCI.

[0055] In some embodiments, during the coupling process of compound 1, the temperature of amide condensation is 20-40° C., and the time of amide condensation is 3-6 hours.

[0056] In some embodiments, the pyrolysis temperature is 0-20°C, preferably 0-10°C.

[0057] In some embodiments, the lysis time is 1 to 3 hours, preferably 1.5 hours.

[0058] In some embodiments, the lysis solution used for lysis contains TFA (trifluoroacetic acid). Specifically, the lysis solution can be a mixture of TFA and water, a mixture of TFA, TIS (triisopropylsilane), water and EDT (1,2-ethanedithiol), or a mixture of TFA, water, thioanisole, PhOH and EDT. More specifically, TFA / water = 95:5, TFA / TIS / water / EDT = 90:2.5:2.5:5, TFA / water / thioanisole / PhOH / EDT = 83:4.3:4.3:6.3:2.1. Preferably, it is a mixture of TFA and water.

[0059] In some embodiments, the cleavage is followed by sedimentation. Specifically, the sedimentation process is as follows: filtering the cleaved material, adding the filtrate to a sedimentation liquid at -10 to 0°C for sedimentation. More specifically, the sedimentation time is 0.5 to 2 hours.

[0060] In one or more embodiments, the sedimentation liquid is diethyl ether or methyl tert-butyl ether, preferably methyl tert-butyl ether.

[0061] In one or more embodiments, the sedimentation temperature is -10 to 10°C, preferably -5 to 5°C.

[0062] In one or more embodiments, the settling time is 0.5 to 2 hours, preferably 1 hour.

[0063] In one or more embodiments, the volume of the sedimentation liquid (ml) is 20 to 40 times, preferably 30 times, the weight (g) of the resin peptide.

[0064] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in combination with specific embodiments and comparative examples.

[0065] Embodiment 1:

[0066] Synthesis of compound 58

[0067] Preparation: Add 10.0g Rink Amide AM resin with a substitution degree of 1.0mol / kg to a solid phase synthesizer, add 50ml dichloromethane to swell the resin, bubble nitrogen for 0.5 hours, drain, wash, add 60ml20% piperidine / N,N-dimethylformamide and stir for 10min, drain, wash, weigh 13.0g Fmoc-Arg(pbf)-OH, 3.4g HOBt, 3.2g DIC, 10.3g HATU, 5.1g EDCI and add to 50ml DMF, activate for 5min, pour into a solid phase synthesizer, bubble nitrogen at 30℃ for 3 hours, detect with ninhydrin, and after the resin ball is colorless, drain, wash, add 60ml20% piperidine / N,N-dimethylformamide and stir for 10min, drain,

[0068] The reaction mixture was washed and Fmoc-Arg(pbf)-OH, HOBt, DIC, HATU and EDCI were added twice repeatedly. 6.3 g of compound 1 was added and the activation method of Fmoc-Arg(pbf)-OH was used for the synthesis. After completion, the reaction mixture was washed with 60 ml of DCM for 3 times, each time for 5 minutes. Finally, the resin was shrunk with 60 ml of methanol for 3 times, each time for 5 minutes. The resin was dried under vacuum at 35°C for 6 hours to obtain 18.35 g of compound 58 resin peptide.

[0069] Cleavage: Measure 171 ml of TFA and 9 ml of water, mix well, cool to 0°C, add 18 g of compound 58 resin peptide into the prepared cleavage solution, control the temperature at 0-10°C and stir for 1 hour, filter to remove the resin, and slowly add the filtrate to 540 ml of methyl tert-butyl ether at -10°C while stirring, control the temperature at -5-5°C, stir for 0.5 hour after the addition, and centrifuge to obtain 9.00 g of light yellow oil with a yield of 115.09% and a purity of 81.16%.

[0070] Purification: The oil was purified by reverse preparative liquid chromatography to obtain 6.75 g of light yellow oil, with a yield of 86.32% and a purity of 99.11%. HRMS (ESI+): calculated for C 38 H 63 N 13 O 5 [M]+: 781.7, found 781.7. Figure 1 , 2 shown.

[0071] Example 2

[0072] Synthesis of compound 58

[0073] Preparation: Add 10.0g Rink Amide AM resin with a substitution degree of 1.0mol / kg to the solid phase synthesizer, add 50ml dichloromethane to swell the resin, bubble nitrogen for 0.5 hours, drain, wash, add 60ml20% piperidine / N,N-dimethylformamide and stir for 10min, drain, wash, weigh 13.0g Fmoc-Arg(pbf)-OH, 3.2g HOSu, 2.9g EDC, 10.3g HATU, 5.1g EDCI and add them to 50ml dichloromethane, activate for 5min, pour into the solid phase synthesizer, bubble nitrogen at 30℃ for 3 hours, detect with ninhydrin, and the resin ball is colorless, drain, wash, add 60ml20% piperidine / N,N-dimethylformamide and stir for 10min,

[0074] The reaction mixture was drained and washed, and Fmoc-Arg(pbf)-OH, HOSu, EDC, HATU, and EDCI were added twice repeatedly. 6.3 g of compound 1 was added and the reaction mixture was synthesized according to the Fmoc-Arg(pbf)-OH activation method. After completion, the reaction mixture was washed with 60 ml of DCM for 3 times, each time for 5 minutes. Finally, the resin was shrunk with 60 ml of methanol for 3 times, each time for 5 minutes. The resin was then dried in vacuo at 35°C for 6 hours to obtain 17.51 ​​g of compound 58 resin peptide.

[0075] Cleavage: Measure 162 ml of TFA and 8 ml of water, mix well, cool to 0°C, add 17 g of compound 58 resin peptide into the prepared cleavage solution, control the temperature at 0-10°C and stir for 1 hour, filter to remove the resin, and slowly add the filtrate to 510 ml of methyl tert-butyl ether at -10°C while stirring, control the temperature at -5-5°C, stir for 0.5 hour after the addition, and centrifuge to obtain 8.17 g of light yellow oil with a yield of 104.52% and a purity of 80.76%.

[0076] Purification: The oil was purified by reverse preparative liquid chromatography to obtain 6.44 g of light yellow oil with a yield of 82.35% and a purity of 99.06%.

[0077] Embodiment 3:

[0078] Synthesis of compound 58

[0079] Preparation: In a solid phase synthesizer, add 10.0g of HMBA resin with a substitution degree of 1.0mol / kg, add 50ml of dichloromethane to swell the resin, bubble nitrogen for 0.5 hours, drain, wash, add 60ml of 20% piperidine / N,N-dimethylformamide and stir for 10min, drain, wash, weigh 13.0g of Fmoc-Arg(pbf)-OH, 3.2g of HOSu, 2.9g of EDC, 10.3g HATU and 5.1g EDCI were added to 50ml tetrahydrofuran and activated for 5min. The mixture was poured into a solid phase synthesizer and reacted at 30°C with nitrogen bubbling for 3 hours. After the resin ball was colorless after detection by ninhydrin, the liquid was drained and washed. 60ml 20% piperidine / N,N-dimethylformamide was added and stirred for 10min. The liquid was drained and washed. Fmoc-Arg(pbf)-OH, HOSu, EDC, HATU and EDCI were added twice. 6.3g of compound 1 was added and the activation method of Fmoc-Arg(pbf)-OH was used for synthesis. After completion, the resin was washed with 60ml DCM for 3 times for 5 minutes each time. Finally, the resin was shrunk with 60ml methanol for 3 times for 5 minutes each time. The resin was dried in vacuo at 35°C for 6 hours to obtain 17.44g of compound 58 resin peptide.

[0080] Cleavage: Measure 162 ml of TFA and 8 ml of water, mix well, cool to 0°C, add 17 g of compound 58 resin peptide into the prepared cleavage solution, control the temperature at 0-10°C and stir for 1 hour, filter to remove the resin, and slowly add the filtrate to 420 ml of methyl tert-butyl ether at -10°C while stirring, control the temperature at -5-5°C, stir for 0.5 hour after the addition, and centrifuge to obtain 7.92 g of light yellow oil with a yield of 101.26% and a purity of 78.52%.

[0081] Purification: The oil was purified by reverse preparative liquid chromatography to obtain 6.21 g of light yellow oil with a yield of 79.41% and a purity of 99.18%.

[0082] Embodiment 4:

[0083] Synthesis of compound 58

[0084] Preparation: Add 10.0 g of HMPA resin with a degree of substitution of 1.2 mol / kg to a solid phase synthesizer, add 50 ml of dichloromethane to swell the resin, bubble nitrogen for 0.5 hours, drain, wash, add 60 ml of 20% piperidine / N,N-dimethylformamide, stir for 10 minutes, drain, wash, weigh 15.6 g of Fmoc-Arg(pbf)-OH, 5.1 g of HONB, 4.8 g of DCC, 12.8g HBTU and 6.1g EDCI were added to 50ml DMF and activated for 5min. The mixture was poured into a solid phase synthesizer and reacted at 30°C for 3 hours under nitrogen bubbling. After the resin ball was colorless after detection by ninhydrin, the liquid was drained and washed. 60ml 20% piperidine / N,N-dimethylformamide was added and stirred for 10min. The liquid was drained and washed. Fmoc-Arg(pbf)-OH, HONB, DCC, HBTU and EDCI were added twice. 7.6g of compound 1 was added and the Fmoc-Arg(pbf)-OH activation method was used for the synthesis. After completion, the resin was washed with 60ml DCM for 3 times for 5 minutes each time. Finally, the resin was shrunk with 60ml methanol for 3 times for 5 minutes each time. The resin was dried in vacuo at 35°C for 6 hours to obtain 19.19g of compound 58 resin peptide.

[0085] Cleavage: Measure 180 ml of TFA and 10 ml of water, mix well, cool to 0°C, add 19 g of compound 58 resin peptide into the prepared cleavage solution, control the temperature at 0-10°C and stir for 1 hour, filter to remove the resin, and slowly add the filtrate to 475 ml of methyl tert-butyl ether at -10°C while stirring, control the temperature at -5-5°C, stir for 0.5 hour after the addition, and centrifuge to obtain 9.88 g of light yellow oil with a yield of 105.32% and a purity of 79.40%.

[0086] Purification: The oil was purified by reverse preparative liquid chromatography to obtain 7.70 g of light yellow oil with a yield of 82.10% and a purity of 99.06%.

[0087] Embodiment 5:

[0088] Synthesis of compound 58

[0089] Preparation: Add 10.0g of Wang resin with a substitution degree of 0.92mol / kg to a solid phase synthesizer, add 50ml of dichloromethane to swell the resin, bubble nitrogen for 0.5h, drain, wash, add 60ml of 20% piperidine / N,N-dimethylformamide and stir for 10min, drain, wash, weigh 12.0g of Fmoc-Arg(pbf)-OH, 3.1g of HOBt, 2.9g of DIC, 9.5g of HATU, and 4.7g of EDCI and add them to 50ml of dichloromethane, activate for 5min, pour into a solid phase synthesizer, bubble nitrogen at 30°C for 3h, and react with indoletriol. Ketone detection, after the resin ball is colorless, drain the liquid, wash, add 60ml20% piperidine / N,N-dimethylformamide and stir for 10min, drain the liquid, wash, repeat the feeding of Fmoc-Arg(pbf)-OH, HOBt, DIC, HATU, EDCI twice, add 5.8g of compound 1, and feed according to the Fmoc-Arg(pbf)-OH activation method. After synthesis, wash with 60mlDCM 3 times, 5 minutes each time, and finally shrink the resin with 60ml methanol 3 times, 5 minutes each time, and place it at 35°C for vacuum drying for 6 hours to obtain 16.62g of compound 58 resin peptide.

[0090] Cleavage: Measure 152 ml of TFA and 8 ml of water, mix well, cool to 0°C, add 16 g of compound 58 resin peptide into the prepared cleavage solution, control the temperature at 0-10°C and stir for 1 hour, filter to remove the resin, and slowly add the filtrate to 390 ml of methyl tert-butyl ether at -10°C while stirring, control the temperature at -5-5°C, stir for 0.5 hour after the addition, and centrifuge to obtain 7.25 g of light yellow oil with a yield of 100.77% and a purity of 77.43%.

[0091] Purification: The oil was purified by reverse preparative liquid chromatography to obtain 5.86 g of light yellow oil with a yield of 81.45% and a purity of 99.03%.

[0092] Embodiment 6:

[0093] Synthesis of compound 58

[0094] Preparation: 10.0 g of AMEBA resin with a degree of substitution of 0.8 mol / kg was added to a solid phase synthesizer, 50 ml of dichloromethane was added to swell the resin, nitrogen was bubbled for 0.5 hours, the liquid was drained, washed, 60 ml of 20% piperidine / N,N-dimethylformamide was added and stirred for 10 minutes, the liquid was drained, washed, 9.6 g of Fmoc-Arg(Pmc)-OH, 2.8 g of HOBt, 2.6 g of DIC, 10.2 g of HBTU, and 4.2 g of EDCI were weighed and added to 50 ml of dichloromethane, activated for 5 minutes, poured into a solid phase synthesizer, nitrogen was bubbled at 30°C for 3 hours, and indene was used to react with indene trichloride. Ketone detection, after the resin ball is colorless, drain the liquid, wash, add 60ml20% piperidine / N,N-dimethylformamide and stir for 10min, drain the liquid, wash, repeat the feeding of Fmoc-Arg(Pmc)-OH, HOBt, DIC, HBTU, EDCI twice, add 5.2g of compound 1, and feed according to the Fmoc-Arg(Pmc)-OH activation method. After synthesis, wash with 60mlDCM 3 times, 5 minutes each time, and finally shrink the resin with 60ml methanol 3 times, 5 minutes each time, and place it at 35°C for vacuum drying for 6 hours to obtain 15.46g of compound 58 resin peptide.

[0095] Cleavage: 135 ml TFA, 4 ml TIS, 4 ml water and 7.5 ml EDT were mixed and cooled to 0°C. 15 g of compound 58 resin peptide was added to the prepared cleavage solution and stirred at 0-10°C for 1 hour. The resin was removed by filtration and the filtrate was slowly added to 450 ml of methyl tert-butyl ether at -10°C while stirring. The temperature was controlled at -5-5°C. After the addition, the mixture was stirred for 0.5 hour and centrifuged to obtain 6.35 g of light yellow oil with a yield of 101.48% and a purity of 78.15%.

[0096] Purification: The oil was purified by reverse preparative liquid chromatography to obtain 4.69 g of light yellow oil with a yield of 74.97% and a purity of 99.09%.

[0097] Comparative Example 1:

[0098] Synthesis of compound 58

[0099] Preparation: Add 10.0g Rink Amide AM resin with a substitution degree of 1.0mol / kg to the solid phase synthesizer, add 50ml dichloromethane to swell the resin, bubble nitrogen for 0.5 hours, drain, wash, add 60ml20% piperidine / N,N-dimethylformamide and stir for 10min, drain, wash, weigh 13.0g Fmoc-Arg(pbf)-OH, 3.4g HOBt, 3.2g DIC and add them to 50ml DMF, activate for 5min, pour into the solid phase synthesizer, bubble nitrogen at 30℃ for 3 hours, detect with ninhydrin, about 20% of the resin balls are blue, extend the reaction for 3h, detect with ninhydrin again, still about 20% of the resin balls are blue, drain, wash, cap with acetic acid, add 60ml after washing 20% piperidine / N,N-dimethylformamide was stirred for 10 min, the liquid was drained, washed, and Fmoc-Arg(pbf)-OH, HOBt and DIC were repeatedly added twice. 6.3 g of compound 1 was added and the Fmoc-Arg(pbf)-OH activation method was used for the synthesis. After completion, it was washed with 60 ml of DCM for 3 times, each time for 5 minutes. Finally, the resin was shrunk with 60 ml of methanol for 3 times, each time for 5 minutes. It was placed at 35°C for vacuum drying for 6 hours to obtain 13.51 g of compound 58 resin peptide.

[0100] Cleavage: Measure 124 ml of TFA and 6 ml of water, mix well, cool to 0°C, add 13 g of compound 58 resin peptide into the prepared cleavage solution, control the temperature at 0-10°C and stir for 1 hour, filter to remove the resin, and slowly add the filtrate to 540 ml of methyl tert-butyl ether at -10°C while stirring, control the temperature at -5-5°C, stir for 0.5 hour after the addition, and centrifuge to obtain 4.12 g of light yellow oil with a yield of 52.69% and a purity of 75.21%.

[0101] Purification: The oil was purified by reverse preparative liquid chromatography to obtain 2.41 g of light yellow oil with a yield of 30.82% and a purity of 98.19%.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A solid phase synthesis method for antibacterial bakuchiol derivatives, characterized in that: The steps include: Fmoc-Arg(X)-OH was coupled three times on a solid phase synthetic resin to obtain Arg(X)-Arg(X)-Arg(X)-resin, which is a tripeptide intermediate resin; Compound 1 is coupled to the tripeptide intermediate resin to obtain a bakuchiol derivative resin; cracking the bakuchiol derivative resin to obtain the bakuchiol derivative; Wherein, the chemical structural formula of compound 1 is: The chemical structural formula of bakuchiol derivatives is: During the coupling of Fmoc-Arg(X)-OH and the coupling of compound 1, at least two amide condensation agents are added simultaneously during the amide condensation.

2. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 1, characterized in that: The solid phase synthetic resin is one of Rink resin, HMBA resin, HMPA resin, Sieber resin, Wang resin, Nitroveratryl resin, PAL resin, AMEBA resin, Oxime resin, SASRIN resin and Dde resin, preferably Rink resin; Alternatively, the degree of substitution of the solid phase synthesis resin peptide is 0.7 to 1.2 mol / kg, preferably 1 mol / kg.

3. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 1, characterized in that: The protecting group X in Fmoc-Arg(X)-OH is Mtr, pbf, Adoc, Pmc, Trt, Tos, preferably pbf; Alternatively, the solvent used in the solid phase synthesis process is N,N-dimethylformamide, dichloromethane, tetrahydrofuran, preferably N,N-dimethylformamide.

4. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 1, characterized in that: The coupling process of Fmoc-Arg(X)-OH includes amide condensation and removal of the Fmoc protecting group.

5. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 1, characterized in that the coupling In the process of Fmoc-Arg(X)-OH, the amide condensation agent used is a combination of HOBt / DIC and HATU / EDCI, a combination of HOSu / EDC and HATU / EDCI, a combination of HONB / DCC and HATU / EDCI, a combination of HOBt / DIC and HBTU / EDCI, a combination of HOSu / EDC and HBTU / EDCI, a combination of HONB / DCC and HBTU / EDCI, preferably a combination of HOBT / DIC and HATU / EDCI; Or, in the process of coupling compound 1, the amide condensation agent used is a combination of HOBt / DIC and HATU / EDCI, a combination of HOSu / EDC and HATU / EDCI, a combination of HONB / DCC and HATU / EDCI, a combination of HOBt / DIC and HBTU / EDCI, a combination of HOSu / EDC and HBTU / EDCI, a combination of HONB / DCC and HBTU / EDCI, preferably a combination of HOBT / DIC and HATU / EDCI.

6. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 1, characterized in that the coupling During the Fmoc-Arg(X)-OH process, the temperature for amide condensation is 20 to 40°C, and the time for amide condensation is 3 to 6 hours; Alternatively, during the coupling process of compound 1, the temperature of amide condensation is 20 to 40° C., and the time of amide condensation is 3 to 6 hours.

7. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 1, characterized in that the coupling In the process of Fmoc-Arg(X)-OH, the Fmoc protecting group is removed by using piperidine / N,N-dimethylformamide solution.

8. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 1, characterized in that: The cracking temperature is 0 to 20°C, preferably 0 to 10°C; Or, the lysis time is 1 to 3 hours, preferably 1.5 hours; Alternatively, the lysis buffer used for lysis contains TFA.

9. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 1, characterized in that: After cracking, sedimentation is performed; preferably, the sedimentation process is: filtering the cracked material, adding the filtrate to a sedimentation liquid at -10 to 0°C for sedimentation. More specifically, the sedimentation time is 0.5 to 2 hours.

10. The solid phase synthesis method of the antibacterial bakuchiol derivative according to claim 9, characterized in that: The sedimentation liquid is diethyl ether or methyl tert-butyl ether, preferably methyl tert-butyl ether; Or, the sedimentation temperature is -10 to 10°C, preferably -5 to 5°C; Or, the sedimentation time is 0.5 to 2 hours, preferably 1 hour; Alternatively, the volume of the sedimentation liquid is 20 to 40 times, preferably 30 times, the weight of the resin peptide.

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