Xylomexicanins I and J: Limonoids with Unusual B/C Rings from Xylocarpus granatum.

Two tetranortriterpenoids with new skeletons, xylomexicanins I and J (1 and 2), were isolated during the investigation of chemical constituents from seeds of the Chinese mangrove, Xylocarpus granatum. Xylomexicanin I (1) is an unprecedented limonoid with bridged B- and C-rings. A biosynthesis pathway for 1 from xylomexicanin F is proposed.

Inhibitory effect of 13 taxane diterpenoids from Chinese yew (Taxus chinensis var. mairei) on the proliferation of HeLa cervical cancer cells.

The inhibitory effect of 13 taxanes isolated from the Chinese yew (Taxus chinensis var. mairei) on the proliferation of human cervical cancer HeLa cells were examined using an MTT assay. Four compounds having a hydrophobic cinnamate side chain showed antiproliferative activity, which may be due to increased cell permeability.

Chemical Constituents of Plants from the Genus Eupatorium (1904-2014).

Eupatorium (family: Compositae), which comprises nearly 1200 species, is distributed throughout tropical America, Europe, Africa, and Asia. Up to now, the reported constituents from the genus Eupatorium involve flavonoids, terpenoids, pyrrolizidine alkaloids, phenylpropanoids, quinonoids, essential oils, and some others, altogether more than 300 compounds. Studies have shown that Eupatorium and its active principles possess a wide range of pharmacological activities, such as cytotoxic, antifungal, insecticidal, antibacterial, anti-inflammatory, and antinociceptive activities. Currently, effective monomeric compounds or active parts have been screened for pharmacological activities from Eupatorium in vivo and in vitro. Increasing amount of data supports application and exploitation for new drug development.

Xylomexicanins C and D, new mexicanolide-type limonoids from Xylocarpus granatum.

Two new limonoids, named xylomexicanins C and D, were isolated from a dichloromethane extract of the seeds of Xylocarpus granatum cultivated in Hainan, China, and their structures were elucidated on the basis of one- and two-dimensional NMR (including 1H, 13C-NMR, DEPT, 1H-1H COSY, HSQC, HMBC, and NOESY) and confirmed by high-resolution mass spectrometry. Xylomexicanin C exhibited antiproliferative activity against human breast carcinoma cells (KT).

Chemical studies on Taxus canadensis.

A series of new taxanes, 1-93, have been isolated, together with 37 known taxoids including Taxol(®) (paclitaxel) and cephalomannine, from the Canadian yew, Taxus canadensis (Taxaceae) in the past 30 years. These new taxoids possess various skeletons containing 5/7/6, 6/10/6, 6/5/5/6, 6/8/6, and 6/12 ring systems and six new taxanes with four novel skeletons, i.e., a taxane with a 6/6/8/6 ring system, a taxane with a [3.3.3] propellane skeleton, three taxanes with [3.3.3] [3.4.5] dipropellane sytems, as well as a novel taxane with a unique 5/5/4/6/6/6 hexacyclic skeleton, containing a unique [3.3.2] propellane, were isolated for the first time from natural sources. It should be emphasized that 13-acetyl-9-dihydrobaccatin III, a very useful starting material for the semisynthesis of Taxol(®) and Taxotere(®) , represents the most abundant taxane in the needles of this yew tree. These findings establish the above mentioned yew tree as significantly different from the remaining species. On the other hand, some chemical modifications on the taxanes isolated from this plant were carried out.

[Non-taxoid chemical constituents from needles of Taxus cuspidata].

OBJECTIVE: To study the chemical constituents in the needles of Taxus cuspidata collected from Japan. METHODS: Chemical constituents were isolated by column chromatography, TLC and preparative HPLC. The structures were identified on the basis of NMR spectral analysis. RESULTS: Six non-taxoids were isolated and identified as: 4-[(1E)-3-hydroxy-1-buten-1-yl]-3,5,5-trimethyl-2-cyclohexen-1-one (1), megastigm-5-ene-3, 9-diol (2), 6alpha-epoxy-7-megastigmen-9-one (3), 4-(4-hydroxyphenyl)-2-butanone (4), 12-hydroxy-alpha-cyperone (5), scutellarein-7-O-alpha-L-rhamnoside (6). CONCLUSION: Compounds 2 - 6 are isolated from Taxus genus for the first time. Compound 1 is obtained from Taxus cuspidata for the first time.

PPARγ agonist from Chromolaena odorata.

A phytochemical investigation of Chromolaena odorata resulted in the isolation of five new compounds, 5aα,6,9,9aß,10-pentahydro-10ß-hydroxy-7-methylanthra[1,2-d][1,3]dioxol-5-one (1), 1,2-methylenedioxy-6-methylanthraquinone (2), 3-hydroxy-1,2,4-trimethoxy-6-methylanthraquinone (3), 3-hydroxy-1,2-dimethoxy-6-methylanthraquinone (4), and 7-methoxy-7-epi-medioresinol (5), together with 12 known compounds, odoratin (6), 3ß-acetyloleanolic acid (7), ursolic acid (8), ombuin (9), 4,2'-dihydroxy-4',5',6'-trimethoxychalcone (10), (-)-pinoresinol (11), austrocortinin (12), tianshic acid (13), cleomiscosin D (14), (-)-medioresinol (15), (-)-syringaresinol (16), and cleomiscosin A (17). All the compounds were evaluated for their PPARγ transactivation activity, and compound 6 showed moderate activity with an EC(50) value of 3.10 µM.

Relationship between the structures of taxane derivatives and their microtubule polymerization activity.

Paclitaxel (Taxol), one of the most potent anticancer drugs, is a microtubule-stabilizing compound that inhibits microtubule depolymerization within the cell. The structure of paclitaxel is composed of two key elements, a taxane ring and an N-benzoylphenylisoserine side chain at C-13. A number of natural and artificial compounds with taxane skeletons have been isolated, but almost none of their bioactivities have been evaluated. In this study, we focused on compounds having a taxane skeleton structure and examined their effects on tubulin dynamics. Although none of these compounds had an N-benzoylphenylisoserine side chain, three were found to promote tubulin assembly. On the other hand, one compound inhibited tubluin assembly in a way similar to nocodazole. These compounds exhibited novel structure-activity relationships of taxane compounds.

Antitumour activities of sesquiterpene lactones from Inula helenium and Inula japonica.

Eight sesquiterpene lactones were isolated from the roots of Inula helenium and flowers of I. japonica. Among them, isoalantolactone (3) and santamarine (6) exhibited significant growth inhibitory activities against gynecologic cancer cell lines, while others weakly inhibited the growth of the cell lines (IC50 < or = 100 microM). In addition, 3 significantly inhibited the tumour growth of S180 tumour-bearing mice. Compounds 3 and 6 were not toxic to human embryonic lung fibroblast cells in vitro. These results demonstrated that the antitumour activities are closely related to the structures of the compounds, that is, an alpha-exomethylene-gamma-lactone ring is necessary for these activities.

Sesquiterpene lactone dimers from the fruit of Carpesium abrotanoides L.

Seven undescribed sesquiterpene lactone dimers (SLDs) (carpeabrodilactones A-G), one known SLD, and six known sesquiterpenes were isolated from the fruit of Carpesium abrotanoides L. Carpeabrodilactone A was a dimeric carabrane featuring a rare C-13-C-13' linkage. Carpeabrodilactones B and C are the first two SLDs to be described possessing a carabranolide unit and a guaianolide unit connected by an O-ether linkage. The structures of the SLDs were assigned based on HRESIMS, NMR analysis, 13C NMR calculation, ECD calculation, and modified Mosher's method. Four SLDs showed potent cytotoxicity against K562 and/or A549 cells, with IC50 values below 10 µM, but none inhibited protein tyrosine phosphatases at 40 µM, including PTP1B, SHP1, CD45, and TCPTP.

Novel taxa-4(20),12-diene and 2(3→20)abeotaxane from needles of Taxus canadensis.

A novel 6/8/6-membered taxane with a rare C-12(13)-double bond and rare 2(3→20)abeotaxane were isolated from the needles of Taxus canadensis. Their structures were characterized as 7ß,9α,10ß-triacetoxytaxa-4(20),12-diene-2α,5α,11ß-triol (1) and 2α,7ß,10ß-triacetoxy-5α-hydroxy-2(3→20)abeotaxa-4(20),11-diene-9,13-dione (2) on the basis of 1D and 2D spectroscopic data. 1 is the first example of a natural taxane without substitution at both C-13 and C-14.

Achillinin A, a cytotoxic guaianolide from the flower of Yarrow, Achillea millefolium.

Achillinin A (2ß,3ß-epoxy-1α,4ß,10α-trihydroxyguai-11(13)-en-12,6α-olide, 1), a new guaianolide isolated from the flower of Achillea millefolium, exhibited potential antiproliferative activity to A549, RERF-LC-kj and QG-90 cells with 50% inhibitory concentration (IC(50)) values of 5.8, 10 and 0.31 µM, respectively.

A novel taxane 13-glucoside and other taxanes from the leaves of Taxus cuspidata.

Three new taxanes, 2 α,9 α,10 ß-triacetoxy-13 α-( ß-D-glucopyranosyloxy)taxa-4(20),11-dien-5 α-ol, 5 α,10 ß,13 α-triacetoxytax-11-ene-2 α,7 ß,9 α,20-tetraol, and 5 α,10 ß,13 ß-triacetoxy-2 α,7 ß-dihydroxy-2(3→20) abeotaxa-4(20),11-dien-9-one, were isolated from the leaves of the Japanese yew, Taxus cuspidata. Compound 1 is the first example of a taxane with 13-glycosidic linkage.

[Studies on preparation and dissolution test in vitro of intragastric floating two-chamber osmotic pump tablets of total alkaloids of Coptis chinensis and Evodia rutaecarpa].

OBJECTIVE: To study prescription and technique of intragastric floating two-chamber osmotic pump tablets (TCOPT) of total alkaloids of Coptis chinensis and Evodia rutaecarpa and inspect release property in vitro. METHODS: The orthogonal experiment was designed to screen prescription and technique. RESULTS: The optimization of prescription and technique were as follows: the expanding agent was a mixture of PEO and HPMC as a ratio of 4:1; the osmotic agent in propelling layer contained sodium chloride 20 mg, PEG 400 in the cellulose acetate, 10%; coating membrane in core tablet, 9%. The release behavior of TCOPT coincidented with zero-level equation well and the character of controlled-release was transparent. CONCLUSION: TCOPT has good effect of controlled-release in vitro and the release behavior in vivo need to be inspected.

Two new flavan-flavanones from Sarcandra hainanensis.

Chemical study of the whole plants of Sarcandra hainanensis yielded two new biflavonoids with a flavan-flavanone skeleton, sarcandrone C (1), D (2) and 6 known compounds (3-8). Structures were elucidated on the basis of NMR spectroscopic methods.

A new taxane with an opened oxetane ring from the needles of Taxus cuspidata.

A new taxoid metabolite was isolated from the MeOH extract of Taxus cuspidata needles. The structure was established as (2alpha,5alpha,7beta,9alpha,10beta,13alpha)-10,13,20-tris(acetyloxy)-1,4,5,7,9-pentahydroxytax-11-en-2-yl benzoate on the basis of spectral analyses including 1H- and 13C-NMR, HMQC, HMBC, and NOESY, and confirmed by HR-FAB-MS.

Secondary metabolites of plants from the genus Saussurea: chemistry and biological activity.

The Asteraceae family comprises ca. 1000 genera, mainly distributed in Asia and Europe. Saussurea DC., as the largest subgenus of this family, comprises ca. 400 species worldwide, of which ca. 300 species occur in China. Most plants in China grow wild in the alpine zone of the Qingzang Plateau and adjacent regions at elevations of 4000 m. Plants of the genus Saussurea (Asteraceae) are used in both traditional Chinese folk medicine and Tibet folklore medicine, since they are efficacious in relieving internal heat or fever, harmonizing menstruation, invigorating blood circulation, stopping bleeding, alleviating pain, increasing energy, and curing rheumatic arthritis. A large number of biologically active compounds have been isolated from this genus. This review shows the chemotaxonomy of these compounds (215 compounds) such as sesquiterpenoids (101 compounds), flavonoids (19 compounds), phytosterols (15 compounds), triterpenoids (25 compounds), lignans (32 compounds), phenolics (23 compounds), and chlorophylls (11 compounds). Biological activities (anti-inflammatory, anticancer, antitumor, hepatoprotective, anti-ulcer, cholagogic, immunosuppressive, spasmolytic, antimicrobial, antiparasitic, antifeedant, CNS depressant, antioxidant, etc.) of these compounds, including structure-activity relationships, are also discussed.

[The recent research progress of chemistry of marine natural products].

Ocean is a unique and excellent resource that provides a diverse array of intriguing natural products. Marine natural products have demonstrated significant and extremely potent biological activities and have captured the attention of natural products chemists in the past few decades. It is increasingly recognized that a wealth of fascinating natural products and novel chemical entities will play a dominant role in the discovery of useful leads for the development of pharmaceutical agents and provide useful probes to lead to breakthroughs in a variety of life-science fields. This article focused on the research progress of chemistry of marine natural products in recent five years.

Taxusecone, a novel taxane with an unprecedented 11,12-secotaxane skeleton, from Taxus cuspidata needles.

Taxusecone, 2alpha,7beta,9alpha,10beta-tetraacetoxy-5alpha,12-dihydroxy-11,12-secotax-4(20)-ene-11,13-dione (1), a novel taxane with an unprecedented skeleton, was isolated from the needles of Taxus cuspidata.