Chrysobalanaceae: Secondary metabolites, ethnopharmacology and pharmacological potential

Many Chrysobalanaceae species, in special Licania and Parinari, are widely used in folk medicine to treat several diseases. This review describes some aspects of their ethnopharmacology potential, biological activities and the secondary metabolites reported so far for Chrysobalanaceae. The chemical constituents of this family include triterpenoids, diterpenoids, steroids and phenylpropanoids like flavonoids as well as chromones derivatives. © 2012 Springer Science+Business Media Dordrecht.

Growth inhibitory, apoptotic and anti-inflammatory activities displayed by a novel modified triterpenoid, cyano enone of methyl boswellates

Triterpenoids are pentacyclic secondary metabolites present in many terrestrial plants. Natural triterpenoids have been reported to exhibit anti-inflammatory and anti-carcinogenic activities. Here, we show that modifications of ring A of boswellic acid (2 cyano, 3 enone) resulted in a highly active growth inhibitory, anti-inflammatory, pro-differentiative and anti-tumour triterpenoid compound called cyano enone of methyl boswellates (CEMB). This compound showed cytotoxic activity on a number of cancer cell lines with IC50 ranging from 0.2 to 0.6 mu M. CEMB inhibits DNA synthesis and induces apoptosis in A549 cell line at 0.25 mu M and 1 mu M concentrations, respectively. CEMB induces adipogenic differentiation in 3T3-L1 cells at a concentration of 0.1 mu M. Finally, administration of CEMB intra-tumourally significantly inhibited the growth of C6 glioma tumour xenograft in immuno-compromised mice. Collectively, these results suggest that CEMB is a very potent anti-tumour compound.

Synthetic Triterpenoid Cyano Enone of Methyl Boswellate Activates Intrinsic, Extrinsic, and Endoplasmic Reticulum Stress Cell Death Pathways in Tumor Cell Lines

We explored the effect of a novel synthetic triterpenoid compound cyano enone of methyl boswellates (CEMB) on various prostate cancer and glioma cancer cell lines. CEMB displayed concentration-dependent cytotoxic activity with submicromolar lethal dose 50% (LD(50)) values in 10 of 10 tumor cell lines tested. CEMB-induced cytotoxicity is accompanied by activation of downstream effector caspases (caspases 3 and 7) and by upstream initiator caspases involved in both the extrinsic (caspase 8) and intrinsic (caspase 9) apoptotic pathways. By using short interfering RNAs (siRNA), we show evidence that knockdown of caspase 8, DR4, Apaf-1, and Bid impairs CEMB-induced cell death. Similar to other proapoptotic synthetic triterpenoid compounds, CEMB-induced apoptosis involved endoplasmic reticulum stress, as shown by partial rescue of tumor cells by siRNA-mediated knockdown of expression of genes involved in the unfolded protein response such as IRE1 alpha, PERK, and ATF6. Altogether, our results suggest that CEMB stimulates several apoptotic pathways in cancer cells, suggesting that this compound should be evaluated further as a potential agent for cancer therapy. Mol Cancer Ther; 10(9); 1635-43. (C)2011 AACR.

唐古特瑞香和大果大戟的化学成分研究

本学位论文由两部分共3章组成。第一部分分别报道2种藏药唐古特瑞香和大果大戟化学成分的研究成果，从2种药用植物共分离鉴定了60个不同的化合物，其中12个为新结构，特别有意义的是发现了2个具有同一新骨架的二萜化合物。第二部分概述了大戟科植物多环二萜的研究进展。 第一部分包括第1和2章。在这2章中分别报道了唐古特瑞香（Daphne tangutica Maxim）和大果大戟（Euphorbia wallichii Hook. f. Fl）化学成分的分离纯化与结构鉴定。实验采用正、反相硅胶柱层析、薄层制备及HPLC等分离方法，从唐古特瑞香的根皮中共分离出32个化合物，通过红外、质谱及核磁共振等波谱方法鉴定了其中的31个，结构类型分别属于瑞香二萜类、木脂素类、香豆素类、苯丙素类及甾体类，其中有三个新的瑞香二萜型化合物，经波谱分析将它们的结构分别鉴定为1,2a-二氢-20-棕榈酰瑞香毒素、1,2a-二氢-5b-羟基-6a,7a-环氧-树脂大戟醇-14-苯甲酸酯及1,2b-二氢-5b-羟基-6a,7a-环氧-树脂大戟醇-14-苯甲酸酯，另外还有13个已知化合物为首次从该植物中分离得到。从大果大戟的根部共分离出33个化合物，鉴定了其中的30个，其主要成分为种类丰富的二萜，包括巨大戟烷型、续随子烷型、对映－阿替生烷型、对映－贝壳杉烷型、对映－松香烷型、ent-trachylobane型、对映－异海松烷型及一新骨架五环二萜ent-wallichane型，另外还有香豆素、甾体、三萜和一些简单的小分子化合物。其中新化合物有9个，经波谱分析将它们的结构分别鉴定为5-O-(2E,4E,6E)-癸三烯酰基-3,20-O-二乙酰基巨大戟醇、5-O-(2E,4Z)-癸二烯酰基-3-O-乙酰基-20-去氧巨大戟醇、3-O-(2E,4Z)-癸二烯酰基-5b,6b-氧-交京大戟醇、7-苯甲酰氧基-3,5,15-三乙酰基-续随子醇、ent-trachylobane-3-one-17-oic-acid、3α-羟基-对映-阿替斯-16-烯-14-酮、3α,6-二羟基-对映-异海松-7-烯-2,15-二酮、wallichanol A 和 wallichanol B，其中，wallichanol A 和 wallichanol B属于一新骨架类型的五环二萜。除此以外，另有13个已知化合物为首次从该植物中分离得到。 第2部分即第3章，首次概述了大戟属植物中多环二萜的化学和药理研究进展。 This dissertation is composed by two parts. The first part reports the phytochemical investigation of two Tibetan medicine plants, Daphne tangutica Maxim and Euphorbia wallichii Hook. f. Fl. Sixty different compounds including ten new compounds and two novel diterpenoids possessing a new carbon skeleton were isolated and identified. The second part is a review about the progress of studies on the polycyclic diterpeniods of the plant family of Euphorbia. The first part consists two chapters, which expatiate on the isolation and identification of chemical constituents from D. tangutica and E. wallichii. Thirty-one compounds were isolated from the root barks of D. tangutica by methods of column chromatography (silica gel, including reversed phase), preparative TLC and HPLC, and their structure were identified as nine daphnane diterpenes, six lignans, nine cumarin derivatives, five phenylpropanoid derivatives, a steroids and a benzoate on the basis of spectroscopic methods including IR, MS and NMR. Among them, three are new diterpenes with skeleton of daphnane and the structure were determined as 1,a-dihydro-20-palimoyl-daphnetoxin, 1,2a-dihydro-5b- hydroxy-6a,7a-epoxy-resiniferonol-14-benzoate and 1,2b-dihydro-5b-hydroxy- 6a,7a-epoxy-resiniferonol-14-benzoate. In addition, thirteen known ones were isolated from this plant for the first time. Isolation of the roots of E. wallichii yielded thirty compounds, twenty-four of them were elucidated as diterpenoids, which belong to different skeleton types of ingenol, lathyrane, ent-atisane, ent-kaurane, ent-abietane, ent-trachylobane, ent-isopimarane and a new pentacyclic skeleton ent-wallichane respectively. The remains including a cumarine, a triterpenoid, a steroid and three compounds with small molecule. Nine new compounds were characterized as 5-O-deca-2E,4E,6E- trienoyl-3,20-O-diacetylingenol, 5-O-deca-2E,4Z-dienoyl-3-O-acetyl-20- deoxyingenol, 3-O-deca-2E,4Z-dienoyl-jolkinol-5b,6b-oxide, 7-benzoyl-3,5,15- triacetyl-7-hydroxylathyrol, ent-trachylobane-3-one-17-oic-acid, 3α-hydroxy-ent- atis-16-en-14-one, 3α,6-dihydroxy-ent-isopimarane-7-en-2,15-dione, wallichanol A and wallichanol B, respectively, by means of comprehensive spectroscopic analysis. Among them, wallichanol A and wallichanol B were two notable novel pentacyclic diterpenoids processing a new rearranged carbon skeleton. And more, thirteen ones were firstly reported from this plant. The third chapter summarizes the research development on chemistry and pharmacology of polycyclic diterpenes from the plant family of Euphorbia for the first time.

Multi-stage mass spectrometric studies of triterpenoid saponins in crude extracts from Acanthopanax senticosus harms

Three triterpenoid saponins in crude extracts from Acanthopanax senticosus Harms have been investigated by use of multi-stage mass spectrometry (MSn) combined with electrospray ionization (ESI), MSn spectra were applied to direct structure elucidation of these saponins in crude plant extracts, in positive and negative ion mode. The characteristic fragmentations of triterpenoid saponins are discussed. The method provides a means of rapid initial screening of crude plant extracts. Copyright (C) 1999 John Wiley & Sons, Ltd.

An ent-Kaurane Diterpene from Euphorbia wallichii

One known ent- kaurane diterpene, ent- 16α, 17- dihydroxykauran- 3-one, were isolated from the roots of Euphorbia wallichii for the first time. Its structure was elucidated on the basis of spectral methods. And the NMR assignments of the compound in CD3OD were given for the first time.

A New Triterpenoid from Amoora dasyclada

Five compounds were isolated from the EtOH extraction of the stem of Amoora dasyclada (How et T. Chen) C. Y. Wu (Meliaceae). On the basis of spectroscopic methods, their structures were elucidated as 24, 25-epoxy-tirucall-7-ene-3, 23-dione (1), 24, 25, 26, 27-tetranortirucall-7-ene-3-oxo-23(21)-lactone (2), taraxerone (3), taraxerol (4) and b-sitosterol (5). Among them, compound 1 was a new triterpenoid, compounds 3-5 were firstly obtained from this plant; compound 2, an tetranortriterpenoid, was firstly isolated from natural sources, and its NMR data were assigned for the first time. Moreover, the D7-bond and the Me-14 in compound 2 were never changed, which has never been found in other tetranortriterpenoids. And the biosynthetic pathway of tetranortriterpenoid was further discussed.

Triterpenoid saponins from a cytotoxic root extract of Sideroxylon foetidissimum subsp. gaumeri

Evaluation of the cytotoxicity of an ethanolic root extract of Sideroxylonfoetidissimum subsp. gaumeri (Sapotaceae) revealed activity against the murine macrophage-like cell line RAW 264.7. Systematic bioassay-guided fractionation of this extract gave an active saponin-containing fraction from which four saponins were isolated. Use of 1D ((1)H, (13)C, DEPT135) and 2D (COSY, TOCSY, HSQC, and HMBC) NMR, mass spectrometry and sugar analysis gave their structures as 3-O-(beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl)-28-O-(alpha-L-rhamnopyranosyl-(1-->3)[beta-D-xylopyranosyl-(1-->4)]-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)-16alpha-hydroxyprotobassic acid, 3-O-beta-D-glucopyranosyl-28-O-(alpha-L-rhamnopyranosyl-(1-->3)[beta-D-xylopyranosyl-(1-->4)]-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)-16alpha-hydroxyprotobassic acid, 3-O-(beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl)-28-O-(alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)-16alpha-hydroxyprotobassic acid, and the known compound, 3-O-beta-D-glucopyranosyl-28-O-(alpha-L-rhamnopyranosyl-(1-->3)[beta-D-xylopyranosyl-(1-->4)]-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)-protobassic acid. Two further saponins were obtained from the same fraction, but as a 5:4 mixture comprising 3-O-(beta-D-glucopyranosyl)-28-O-(alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)-16alpha-hydroxyprotobassic acid and 3-O-(beta-D-apiofuranosyl-(1-->3)-beta-D-glucopyranosyl)-28-O-(alpha-L-rhamnopyranosyl-(1-->3)[beta-D-xylopyranosyl-(1-->4)]-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl)-16alpha-hydroxyprotobassic acid, respectively. This showed greater cytotoxicity (IC(50)=11.9+/-1.5 microg/ml) towards RAW 264.7 cells than the original extract (IC(50)=39.5+/-4.1 microg/ml), and the saponin-containing fraction derived from it (IC(50)=33.7+/-6.2 microg/ml).

Triterpenoid saponins from the cytotoxic root extract of Sideroxylon foetidissimum, an endemic Yucatecan medicinal plant

The flora of the Yucatan peninsula (Mexico) includes approximately 3000 plant species. Sideroxylon foetidissimum Jacq. subsp. gaumeri (Sapotaceae) is an endemic plant to the Yucatan peninsula; its fruit is edible and local people use the plant for medicinal purposes, although no details on its preparation or application are available [1,2]. A preliminary cytotoxic evaluation of the ethanolic root extract of S. foetidissimum revealed a potent activity against murine macrophage like cell line RAW 264.7 (IC50=39.54±4.11µg/mL). The systematic bioassay-guided fractionation of the extract resulted in the identification of the active saponin-containing fraction (IC50=33.69±6.19µg/mL). Four new triterpenoid saponins and a 1:1 mixture of two saponins were isolated from the active saponin- containing fraction. The evaluation of their cytotoxic activity revealed no activity for the tested pure saponins; however, the 1:1 mixture of saponins showed a potent activity (IC50=11.91±1.49µg/mL). The isolation of the saponins was carried out using semi-preparative HPLC. The structural assignments of the pure saponins were based on 1D (1H and 13C and DEPT-135) and 2D (COSY, HMBC, HSQC and TOCSY) NMR and mass spectrometry analyses. In this presentation, the isolation, identification and cytotoxic activity of the isolated compounds is discussed in more detail.

New alkamide and ent-kaurane diterpenoid derivatives from Senecio erechtitoides (Asteraceae)

Fractionation of a MeOH/CH2Cl2 (1/1) extract of the aerial parts of Senecio erechtitoides led to the isolation of six compounds including the hitherto unknown N-phenethylamide derivative named N-(p-hydroxyphenethyl)pentacosanamide (1), and a kauranoid derivative named derivative named ent-7-oxo-16 alpha,17-dihydroxykauran-19-oic acid (2), as well as four known compounds, ent-Kaur-16-en-19-oic acid (3), ent-7 beta-hydroxykaur-16-en-19-oic acid (4), ent-7-oxokaur-16-en-19-oic acid (5), steppogenin 4′-O-beta-d-glucoside (6). Their structures and relative configurations were elucidated on the basis of spectroscopic methods, chemical reactions, and comparison with previously known analogs. All isolates were evaluated for their antimicrobial activity and only diterpenoids were found to possess a potent inhibitor effect against the range of microorganism.

Transport of cryptotanshinone, a major active triterpenoid in Salvia miltiorrhiza Bunge widely used in the treatment of stroke and Alzheimers disease, across the blood-brain

Cryptotanshinone (CTS), a major constituent from the roots of Salvia miltiorrhiza (Danshen), is widely used in the treatment of coronary heart disease, stroke and less commonly Alzheimer's disease. Our recent study indicates that CTS is a substrate for Pglycoprotein (PgP/MDR1/ABCB1). This study has investigated the nature of the brain distribution of CTS across the brain-blood barrier (BBB) using several in vitro and in vivo rodent models. A polarized transport of CTS was found in rat primary microvascular endothelial cell (RBMVEC) monolayers, with facilitated efflux from the abluminal side to luminal side. Addition of a PgP (e.g. verapamil and quinidine) or multi-drug resistance protein 1/2 (MRP1/2) inhibitor (e.g. probenecid and MK-571) in both luminal and abluminal sides attenuated the polarized transport. In a bilateral in situ brain perfusion model, the uptake of CTS into the cerebrum increased from 0.52 ± 0.1% at 1 min to 11.13 ± 2.36 ml/100 g tissue at 30 min and was significantly greater than that of sucrose. Co-perfusion of a PgP/MDR1 (e.g. verapamil) or MRP1/2 inhibitor (e.g. probenecid) significantly increased the brain distribution of CTS by 35.1-163.6%. The brain levels of CTS were only about 21% of those in plasma, and were significantly increased when coadministered with verapamil or probenecid in rats. The brain levels of CTS in rats subjected to middle cerebral artery occlusion and rats treated with quinolinic acid (a neurotoxin) were about 2- to 2.5-fold higher than the control rats. Moreover, the brain levels in mdr1a(-/-) and mrp1(-/-) mice were 10.9- and 1.5-fold higher than those in the wild-type mice, respectively. Taken collectively, these findings indicate that PgP and Mrp1 limit the brain penetration of CTS in rodents, suggesting a possible role of PgP and MRP1 in limiting the brain penetration of CTS in patients and causing drug resistance to Danshen therapy and interactions with conventional drugs that are substrates of PgP and MRP1. Further studies are needed to explore the role of other drug transporters in restricting the brain penetration of CTS and the clinical relevance.

The semi-synthetic kaurane ent-16 alpha-methoxykauran-19-oic acid induces vascular relaxation and hypotension in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A new ent-kaurane diterpene from stems of Alibertia macrophylla K. Schum. (Rubiaceae)

Phytochemical investigations of the stems of a specimen of Alibertia macrophylla led to the isolation and characterization of the new diterpene ent-kaurane-2β,3α,16α-triol (1), along with triterpenes 2-8, iridoids 9-12, and phenolic acids 13-15. The structure of 1 was established based on spectroscopic studies (1H- and 13C-NMR, IR, and HR-ESI-MS). This is the first report of the isolation of a diterpene from the Alibertia genus in Rubiaceae. © 2007 Verlag Helvetica Chimica Acta AG.