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.

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).

[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.

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.

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.

[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.

Xylomexicanins A and B, new Delta14,15-mexicanolides from seeds of the Chinese mangrove Xylocarpus granatum.

Two new mexicanolide-type limonoids, named xylomexicanin A (1) and xylomexicanin B (2), were isolated from seeds of the Chinese mangrove Xylocarpus granatum. Their structures were elucidated on the basis of spectroscopic methods. Compound 1 exhibited antiproliferative activity against human breast carcinoma cells (KT), while 2 did not show inhibitory effects on eleven human tumour cell lines tested.