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Dimers tomoroside A (1) and tomoroside B (2) of the co-occuring known chalcone monomer (3), along with the seven known flavonoid glucosides (4-10), were isolated from the aerial parts of Helichrysum zivojinii Cernjavski & Soska. The structures of the isolated compounds were elucidated by spectroscopic techniques. Compound 1 inhibited topo Ha and hif-1 alpha expression and stimulated doxorubicin anticancer effect, while 2 increased the expression of hif-1 alpha a, probably acting as antioxidant and redox status modulator. Notably, 2 synergized with Tipifarnib showing potential to improve the action of this new chemotherapeutic involved in the modulation of mitogene activated protein (MAP) kinase signaling pathway.

An extended study of minor diarylheptanoids from the bark of black alder has resulted in the isolation of twenty diarylheptanoids, ten of which have not previously been reported (14-18, 20-24). The structures and configurations of all compounds were elucidated by NMR, HRESIMS, UV, IR, and CD. The anti-cancer potency of twenty diarylheptanoids and four previously isolated compounds (7, 10, 12, 13) was investigated in human non-small cell lung carcinoma cell lines (sensitive and multi-drug resistant variants) as well as in normal human keratinocytes. Diarylheptanoids with a p-coumaroyl group, 14 and 18, platyphylloside (1), platyphyllonol-5-O-beta-D-xylopyranoside (2), alnuside B (4) and hirsutenone (9) exhibited strong anti-cancer activity, considerably higher than diarylheptanoid curcumin, which served as a positive control. Compounds 4, 9, 14, and 18 displayed significant selectivity towards the cancer cells. Structure/activity analysis of twenty-four closely related diarylheptanoids revealed a high dependence of cytotoxic action on the presence of a carbonyl group at C-3. Substitution of a heptane chain on C-5 and a number of hydroxyl groups in the aromatic rings also emerged as a significant structural feature that influenced their cytotoxic potential. (C) 2013 Elsevier Ltd. All rights reserved.

Examination of the aerial parts of Achillea clavennae afforded eight guaianolides (1-8), three bisabolenes (9 11), four flavonols (12-15), sesamin (lignan) and isofraxidin (coumarin). The structures of the new compounds (2, 4, 5, 7 and 10) were determined by spectroscopic methods. The antiproliferative action of 2, 8, 9 and 12 were tested to HeLa, K562 and Fem-X human cancer cell lines. Guaianolides 2 (9 alpha-acetoxyartecanin) and 8 (apressin) showed significant cytotoxic effects to all tested lines and inducumenone (9) exhibited a moderate activity. The most active was flavonol centaureidin (12), already known as cytotoxic compound. (c) 2006 Elsevier Ltd. All rights reserved.

Quantitative H-1 NMR measurements revealed Delta(11(13)) sesquiterpene gamma-lactones as the main constituents (greater than or equal to 1% per weight of dried plant material) in the crude extracts of the aerial parts of Amphoricarpos neumayeri ssp. neumayeri and ssp. murbeckii from mountains Orjen and Visitor (Montenegro), respectively. Preparative silica gel chromatography afforded thirteen guai-11(13)-en-12,6alpha-olides, named amphoricarpolides (1-13), with the same relative (1alphaH,4PH,5alphaH,7betaH) configuration of the basic skeleton. The common structural feature of lactones 2-13 was 3beta,15-dioxygenation pattern. The only exception was 1 (3-deoxyamphoricarpolide), containing a single oxygen substituent (15-OH). Eight of them exhibited an additional oxygen substituent, 9beta-OH (5 and 6), 2alpha-OH (8-12), or 2alpha-OAc (13). Compound 7 was epoxydated at 10alpha(14)-position, whereas the remaining lactones contained a 10(14) double bond. (C) 2004 Elsevier Ltd. All rights reserved.

Isolation of 1-O-primeverosyl-3,8-dihydroxy-5-methoxyxanthone and 1-O-gentiobiosyl- 3,7-dimethoxy-8-hydroxyxanthone, along with five known xanthones, isobellidifolin, methylbellidifolin, isoswertianin, methylswertianin and norswertianin-1-O-beta-D-glucoside, from the roots of Swertia punctata is reported. In the aerial parts four xanthones, bellidifolin, methylbellidifolin, swertianolin and mangiferin, and flavone-C-gluco side, isoorientin were identified. The chemotaxonomic and pharmacological significance of these results is discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.

The isolation of two oxidation products of hyperforin from the aerial parts of Hypericum perforatum and their structure determination by means of 2D NMR methods is reported. The products had the same 1-(2-methyl-1- oxopropyl)-2,12-dioxo-3,10β-bis(3-methyl-2-butenyl)-11β-methyl-11α-(4- methyl-3-pentenyl)-5-oxatricyclo[6.3.1.0 4,8 ]-3-dodecene skeleton. In addition, one of them, with the same number of carbons as hyperforin (C 35 H 52 O 5 ), contained a 1-methyl-1-hydroxyethyl group in the 6β- position, whereas the other compound (a hemiacetal, C 32 H 46 O 5 ), presumably a degradation product of hyperforin, exhibited a 6-hydroxy function. The latter was an inseparable mixture of 6α- and 6β-hydroxy epimers undergoing (according to phase sensitive NOESY) mutual interconversion.

The isolation of guaianolides rupicolin-A, rupicolin-B, their acetates and a new germacranolide 1β,10α-epoxy-3β,9β-diacetoxy-11α,13-dihydrocostunolide, identified by means of PS DQF COSY and PS NOESY, from Achillea crithmifolia is reported. A flavonoid jaceidin was also isolated from the same extract.

The isolation of 11(13)-dehydrocriolin [a germacranolide also known as 11(13)-dehydroivaxillin], 2α-hydroxyalantolactone, 4α,5α-epoxy-10α,14-H-inuviscolide (the major component) and carabrone from the aerial parts of Inula helenium is reported. The first two lactones were isolated for the first time from this plant. © 1989.