Methyl 1,2‐Shift Rearrangement on C‐ring and Decarboxylation at C28 of Oleanolic Acid Derivatives

A new oleanolic acid derivative with A‐ring lactone, C‐ring rearrangement and decarboxylation at C28 was synthesized, which was confirmed by HRMS, NMR and X‐ray crystal structure. It is the first report about the methyl rearrangement on C‐ring of oleanolic phenylmethyl ester, and the possible mechanism was proposed as the 1,2‐methyl shift.     

Microbial hydroxylation and glycosidation of oleanolic acid by Circinella muscae and their anti-inflammatory activities

Biotransformation of oleanolic acid (OA) by Circinella muscae AS 3.2695 was investigated. Nine hydroxylated and glycosylated metabolites (1–9) were obtained. Their structures were elucidated as 3β,7β-dihydroxyolean-12-en-28-oic acid (1), 3β,7β,21β-trihydroxyolean-12-en-28-oic acid (2), 3β,7α,21β-trihydroxyolean-12-en- 28-oic acid (3), 3β,7β,15α-trihydroxyolean-12-en-28-oic acid (4), 7β,15α-dihydroxy- 3-oxo-olean-12-en-28-oic acid (5), 7β-hydroxy-3-oxo-olean-12-en-28-oic acid (6), oleanolic acid-28-O-β-D-glucopyranosyl ester (7), 3β,21β-dihydroxyolean-12-en-28- oic acid-28-O-β-D-glucopyranosyl ester (8), and 3β,7β,15α-trihydroxyolean-12-en- 28-oic acid-28-O-β-D-glucopyranosyl ester (9) by spectroscopic analysis. Among them, compounds 4 and 9 were new compounds. In addition, anti-inflammatory activities were assayed and evaluated for the isolated metabolites. Most of the metabolites exhibited significant inhibitory activities on lipopolysaccharides-induced NO production in RAW 264.7 cells.     

Determination of oleanolic acid and ursolic acid in cornel by cyclodextrin-modified micellar electrokinetic chromatography

A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was established for the determination of oleanolic acid and ursolic acid in cornel. The two components were separated in the running buffer of 40 mmol/L sodium borate containing 5% methanol, 25 mmol/L SDS and 15 mmol/L hydroxypropyl-beta-cyclodextrin (HP-beta-CD). The applied voltage was 24 kV. The wavelength of detection was 200 nm. The temperature was kept at 25 C. Cinnamic acid was used as the internal standard. The analytical performance of the method was tested with respect to linearity, precision and recovery. The calibration curves were linear in the range of 10.15-243.6 microg/mL, r=0.9993 (oleanolic acid) and 10.07-241.7 microg/mL, r=0.9994 (ursolic acid); the intra-day precision (RSD) was less than 3.7% (oleanolic acid) and 4.1% (ursolic acid); the inter-day precision (RSD) was less than 4.2% (oleanolic acid) and 4.9% (ursolic acid). The limits of detection were 1.6 microg/mL for both components. The method proved to be sensitive, rapid, accurate and suitable for the determination of oleanolic acid and ursolic acid in cornel.     

新型齐墩果酸糖苷化衍生物的合成及体外抗HCT8活性

为提高齐墩果酸的水溶性和稳定性,以齐墩果酸苷元为起始原料,对其28-COOH进行甲基化修饰后制得齐墩果酸-28-羧甲酯(1)。分别以D-半乳糖、D-葡萄糖、D-氨基葡萄糖为起始原料,通过对糖羟基的保护与去保护,得到一系列的二糖、四糖片段。通过三氯乙酰亚胺酸酯途径和对甲苯硫基途径,利用合成的糖片段对1的3-位羟基进行糖化学结构修饰,合成了4种新型的齐墩果酸糖苷化衍生物(2~5),其结构经1H NMR,13C NMR和MS(ESI)表征。采用MTT法测试了2~5对高表达人结肠癌细胞(HCT8)的体外抑制活性。结果表明:2~5对HCT8有一定的抑制作用,化合物5浓度为1×10^-3 mmol/L时,抑制率达到(98.96±0.10)%。     

几种齐墩果酸糖缀合物的合成

报道了齐墩果酸与四种单糖和二糖（葡萄糖、半乳糖、乳糖及葡萄糖醛酸）进 行糖苷化制备糖缀合物的方法。在合成过程中首先将葡萄糖、半乳糖及乳糖转化成 相应的全苯甲酰三氯亚胺酯糖基供体（10a-10c），将葡萄糖醛酸转化成为1-溴代 乙酰葡萄糖醛酸甲酯糖基供体（10d）；在齐墩果酸的28-位羧基上进行酰胺化引入 ω-氨基羧酸甲酯得到其衍生物6。然后10a-10c在TMSOTf的催化下与化合物6的3-位 羟基进行β-糖苷化；10d在AgOTf的催化下与6进行β-糖苷化，最后脱掉保护基得 到相应的糖缀合物13a-13d，所有目的化合物均为新化合物，其结构经IR，^1H NMR，^13C NMR，2D-COSY，HMQC，DEPT及HRMS进行了确证。     

靶向VEGFR受体抑制剂齐墩果酸衍生物的合成及初步抗肿瘤活性研究

以天然产物齐墩果酸为母体,设计合成齐墩果酸衍生物,采用计算机辅助药物设计,对C-3、C-28位结构改造,设计合成12个未见文献报道的靶向VEGFR受体抑制剂; 采用噻唑蓝(MTT)法,用人肝癌细胞(HepG2)和乳腺癌细胞(MCF-7)对其进行初步体外抗肿瘤活性筛选;其结构经1H-NMR、13C-NMR谱确证。活性测试得出化合物I7、II1与阳性对照药相比有较强抑制作用,其抗肿瘤活性高于母体OA,分子对接结果显示I7和II1 与 VEGFR 受体具有较好的结合能力,值得进一步研究。     

熊果酸与齐墩果酸高效液相色谱分离条件优化

描述了熊果酸、齐墩果酸色谱保留行为与流动相pH和有机溶剂体积分数之间的函数关系,并求解了各自模型中的9个参数,得到在流动相中熊果酸的电离常数pKa=4.8145,齐墩果酸电离常数pKa=4.9317。文章还对模型外推过程中存在的误差进行了校正,并运用校正后的模型预测熊果酸的容量因子,实验值接近预测值,误差小于5%。最后采用熊果酸和齐墩果酸的容量因子与流动相pH和有机溶剂组成之间的函数关系,进行了两者在同一流动相中分离条件的优化,获得了最佳的分离条件:流动相中甲醇体积分数为85.2%,pH为6.50。     

Segetoside L, A New Triterpenoid Saponin from Vaccaria segetalis

A new triterpenoid saponin, named segetoside L, was isolated from the seeds of Vaccaria segetalis. On the basis of spectral data and chemical reaction, its structure was established as 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl oleanolic acid 3-O-β-D-glucopyranosyl-(1→3)- [β-D-galactopyranosyl-(1→2)]-β-D-galactopyranoside.     

齐墩果酸乙酰氧基取代三烯的合成及氧化

以齐墩果酸(1)为原料,依次经过17-羧基的甲酯化、3-羟基的苯甲酰化、12-双键的臭氧化、Br2/HBr脱氢、羰基的烯醇乙酰化以及C环的光照开环,得到12-乙酰氧基取代的三烯化合物6。 采用不同的氧化剂,如O3、间氯过氧苯甲酸、H2O2、过氧叔丁醇以及Na2S2O8等对化合物6进行氧化,得到了十氢萘型的手性合成子以及环氧化或者环氧内酯化的齐墩果酸衍生物。     

Development and validation of a quantification method for oleanolic acid and hederagenin in rat plasma: application to the pharmacokinetic study

A rapid and sensitive liquid chromatography tandem mass spectrometry (LC–MS/MS) was developed and validated for simultaneous quantification of oleanolic acid and hederagenin in rat plasma. After the two analytes were extracted with liquid–liquid extraction, chromatographic separation was performed on a C₁₈ column with acetonitrile and water (85:15, v /v) as mobile phase at a flow rate of 0.4 mL/min. Calibration curves exhibited good linearity (r > 0.995) over the ranges of 0.41–82.0 ng/mL for oleanolic acid and 0.32–64.0 ng/mL for hederagenin, respectively. The lower limit of quantifications (LLOQs) in plasma were 0.41 ng/mL for oleanolic acid and 0.32 ng/mL for hederagenin. The established LLOQs were within the concentration needed for the assay in plasma, which met the requirements to evaluate their pharmacokinetics of oleanolic acid and hederagenin. This developed assay was successfully applied in the pharmacokinetic study of oleanolic acid and hederagenin in rats after oral administration of Rhizoma Clematidis extract.     

Anti-Cancer Potential of Synthetic Oleanolic Acid Derivatives and Their Conjugates with NSAIDs

Naturally occurring pentacyclic triterpenoid oleanolic acid (OA) serves as a good scaffold for additional modifications to achieve synthetic derivatives. Therefore, a large number of triterpenoids have been synthetically modified in order to increase their bioactivity and their protective or therapeutic effects. Moreover, attempts were performed to conjugate synthetic triterpenoids with non-steroidal anti-inflammatory drugs (NSAIDs) or other functional groups. Among hundreds of synthesized triterpenoids, still the most promising is 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO), which reached clinical trials level of investigations. The new group of synthetic triterpenoids are OA oximes. The most active among them is 3-hydroxyiminoolean-12-en-28-oic acid morpholide, which additionally improves the anti-cancer activity of standard NSAIDs. While targeting the Nrf2 and NF-κB signaling pathways is the main mechanism of synthetic OA derivatives′ anti-inflammatory and anti-cancer activity, most of these compounds exhibit multifunctional activity, and affect cross-talk within the cellular signaling network. This short review updates the earlier data and describes the new OA derivatives and their conjugates in the context of modification of signaling pathways involved in inflammation and cell survival and subsequently in cancer development.     

新型齐墩果酸衍生物的合成及其抗肿瘤活性

以齐墩果酸(1)为原料,经3-羟基乙酰化,17-位羧基甲酯化,11-位碳羰基化及光照反应,首次实现了1的10-位角甲基的活化,合成了新型的齐墩果酸衍生物———3β-乙酰氧基-11α-羟基-11,25-环-齐墩果-12-烯-28-酸甲酯(4),其结构经1H NMR,13C NMR,IR和MS表征。采用SRB法测试了1～4及1的衍生物7～9对N-04,Bre-04和Lu-04细胞株的体外抑制活性,结果表明,4,8和9具有明显的抑制肿瘤细胞生长的能力。     

两种天然齐墩果酸皂苷的合成

3-O-[β-D-Glucopyranosyl-（1→3）-α-L-arabinopyranosyl]-oleanolic acid-28-O-[β-D-glucopyranosyl] ester 1 was synthesized concisely by a convergent strategy. Using stepwise fashion for the synthesis of saponin 2, 3-O-{[β-D-glucopyranosyl-（1→2）]-[α-L-arabinopyranosyl-（1→3）]-α-L-arabinopyranosyl）-oleanolic acid-28-O-（β- D-glucopyranosyl） ester, an abnormal phenomenon, that the terminal arabinosyl residue took the ^1C4 conformation instead of typical ^4C1 form, was observed. Deprotection or heating could not resume the normal conformation, which resulted in the product of 2＇ not 2.     

Triterpene glycosides from Kalopanax septemlobum. VI. Glycosides from leaves of Kalopanax septemlobum var. typicum introduced to crimea

Thirteen known glycosides of hederagenin and oleanolic acid and the three new triterpene glycosides of oleanolic acid-28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester 3-O-β-D-glucopyranosyl-(1→4)-O-β-D-xylopyranosyl-(1→ 3)-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside of oleanolic acid and the 28-O-α-L-rhamnopyranosyl-(1→4)-O-6-O-acetyl-β-D-glucopyranosyl-(1→ 6)-O-β-D-glucopyranosyl esters 3-O-β-D-xylopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranoside of oleanolic acid and 3-O-β-D-glucopyranosyl-(1→4)-O-β-Dxylopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→ 2)-O-α-L-arabinopyranoside of oleanolic acid were isolated from leaves of Kalopanax septemlobum var. typicum introduced to Crimea. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–43, January–February, 2006.     

Surface molecularly imprinted polymers prepared by two‐step precipitation polymerization for the selective extraction of oleanolic acid from grape pomace extract

Surface molecularly imprinted polymers were successfully prepared by a novel two‐step precipitation polymerization method. The first‐step allowed the formation of 4‐vinylpyridine divinylbenzene and trimethylolpropane trimethacrylate copolymeric microspheres. In the second‐step precipitation polymerization, microspheres were modified with a molecularly imprinting layer of oleanolic acid as template, methacrylic acid as functional monomer, and divinylbenzene/ethylene glycol dimethacrylate as cross‐linker. The obtained polymers had an average diameter of 4.43 μm and a polydispersity index of 1.011; adsorption equilibrium was achieved within 40 min, with adsorption capacity reaching 27.4 mg/g. Subsequently, the polymers were successfully applied as the adsorbents of molecularly imprinted solid‐phase extraction to separate and purify the oleanolic acid from grape pomace. The content of oleanolic acid in the grape pomace extract was enhanced from 13.4 to 93.2% after using the molecularly imprinted solid‐phase extraction process. This work provides an efficient way for effective oleanolic acid separation and enrichment from complex matrices, which is especially valuable in industrial production.     

Continuous separation of maslinic and oleanolic acids from olive pulp by high‐speed countercurrent chromatography with elution‐extrusion mode

In this work, a continuous high‐speed countercurrent chromatography method has been developed on the basis of elution‐extrusion mode and this method was successfully applied to the separation of maslinic and oleanolic acid from the extract of olive pulp. In the process of ‘elution’, the sample solution was continuously loaded into the column and the maslinic acid was steadily eluted out in this step while highly retained oleanlic acid always stayed in the column. In the process of ‘extrusion’, the oleanlic acid was pushed out of the column with the stationary phase. In this way, we achieved a large sample loading. A total of 120 mL sample solution (about 89.55% of the column volume) which contains 600 mg olive pulp extract was pumped in the apparatus by a constant‐flow pump and the maslinic and oleanolic acids were largely separated within 120 min. Both of these two compounds presented high yields and high purities (271.6 mg for maslinic acid with 86.7% and 83.9 mg oleanolic acids with 83.4%).     

High-Speed Separation of Oleanolic acid and Ursolic acid from the Fruit of Ligustrum Lucidum ait and Crataegus by Cyclodextrin-Modified Micellar Electrokinetic Chromatography

ABSTRACT

A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) technique for determining oleanolic acid and ursolic acid in the fruit of Ligustrum lucidum Ait and Crataegus was developed. The two bio-active components were successfully separated within 4 minutes using a pH 8.5 sodium borate buffer containing 60mM SDS and 2mM γ-CD. The correlation coefficients of the linear calibration graphs for the analyses exceeded 0.9980. The effects of pH, SDS, γ-CD, sodium borate and temperature on separation were also investigated.     

Optimization of carvacrol,rosmarinic, oleanolic and ursolic acid extraction from oregano herbs (Origanum onites L., Origanum vulgare spp. hirtum and Origanum vulgare L.)

The aim of our study was to increase the extraction efficiency of carvacrol, rosmarinic, oleanolic and ursolic acid from the different species of oregano herbs (Origanum onites L., Origanum vulgare spp. hirtum and Origanum vulgare L.). Various extraction methods (ultrasound-assisted, heat-reflux, continuous stirring, maceration, percolation) and extraction conditions (different solvent, material:solvent ratio, extraction temperature, extraction time) were used, and the active substances were determined by HPLC. The lowest content of carvacrol, rosmarinic, oleanolic and ursolic acid was obtained by percolation. During heat-reflux extraction, the content of active substances depended on the solvent used: ethanol/non-aqueous solvent (glycerol or propylene glycol) mixture was more effective compared with ethanol alone. The results showed that for each species of oregano the most optimal extraction method should be selected to maximize the content of biologically active substances in the extracts.     

Complete assignments of 1H and 13C NMR resonances of oleanolic acid, 18α‐oleanolic acid,ursolic acid and their 11‐oxo derivatives

Complete assignments of ¹H and ¹³C NMR chemical shifts for oleanolic acid, 18α‐oleanolic acid, ursolic acid and their 11‐oxo derivatives based on ¹H, ¹³C, 2D DQF‐COSY, NOESY, HSQC, HMBC and HSQC‐TOCSY experiments were achieved. Copyright © 2003 John Wiley & Sons, Ltd.     

化学衍生辅助液相色谱-串联质谱测定枇杷膏中的齐墩果酸和熊果酸

建立了一种液相色谱-串联质谱(LC-MS/MS)同时测定齐墩果酸和熊果酸含量的分析方法,利用衍生化试剂N,N-二甲基乙二胺(DMED)和d4-N,N-二甲基乙二胺(d4-DMED)分别衍生样品和标准工作溶液中的目标分析物,并将标准工作液的衍生产物作为稳定同位素内标。该方法线性关系良好,相关系数均0.99;齐墩果酸和熊果酸的检出限(S/N=3)分别为0.92 ng/L和1.06 ng/L,加标回收率分别为98.7%~102.7%和97.2%~105.0%。该方法简单、快速、准确,可满足枇杷膏中齐墩果酸和熊果酸高灵敏度检测的需求。