Search

From the fresh aerial parts of Senecio selloi (Asteraceae), two diastereomeric triterpenes with a hitherto unknown skeleton have been isolated. The structure has been elucidated mainly by advanced NMR experiments, including inverse techniques, HMQC, HMBC, ROESY.

Three new compounds, docosanoic cinnamate, 7-hydroperoxy-5,6-E-dehydro-6,7-dihydronerol and 2-(3-methylbut-3-enyl)-3-methyl-2,5-dihydrofuran were isolated from the leaves of Heterothalamus alienus and their structures determined by spectroscopical methods.

Two new alkaloids, named isohyperectine and leptocarpine, were isolated from the whole plants of Hypecoum leptocarpum, along with the eight known alkaloids, dihydrosanguinarine, 8-acetonyldihydrosanguinarine, 8-methoxydihydrosanguinarine, oxohydrastinine, allocryptopine, protopine, hyperectine and corydamine. All structures were determined by spectroscopic methods.

Phytochemical investigation of Dactylicapnos torulosa yielded two known compounds, ( − )- cis - N -methylstylopiumchloride and hydrastinine chloride; and five new alkaloids, dactyline, 8-hydroxydihydrosanguinarine and dactylidine, as well as dactylicapnosine and dactylicapnosinine with novel CNOC moieties. All structures were elucidated by spectroscopical methods. The structure of dactylicapnosine was also determined by single crystal X-ray diffraction analysis.

Three bisepoxylignan glycosides were isolated from Stauntonia hexaphylla . One is a new compound, (+)-1-hydroxysyringaresinol-1-β- d -glucoside named staunoside C, whilst the other two, (+)-fraxiresinol-1-β- d -glucoside and (+)-1-hydroxypinoresinol-1-β- d -glucoside, are reported in this genus for the first time. Structures were established on the basis of spectroscopic analysis and chemical evidence, and their 1 H NMR signals were assigned in detail by means of 2D-NMR techniques.

On the basis of spectroscopic and chemical methods, the structures of two new bisdesmosidic triterpenoid glycosides, named staunoside D and E, which were isolated from Stauntonia hexaphylla, were established as 3-O-(beta-D-glucopyranosyl(1-->2)-[beta-D- glucopyranosyl(1-->3)]-beta-D-glucopyranosyl)-hederagenin-28- O-[beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl] ester and 28-O-[alpha-L-rhamnopyranosyl (1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosyl]ester, respectively. Three known triterpenoid glycosides were also isolated. A new proglycoside was isolated from the cleavage of the ester-glycosidic linkage and its structure characterized.

Three new cucurbitacins were isolated from the roots of Wilbrandia ebracteata and their structures established as 16α, 23α-epoxy-2β,3β,20β-trihydroxy-10α,23β-cucurbit-5,24-dien-11-one, 16α,23α-epoxy-2β,3β,20β-trihydroxy- 10α,23α-cucurbit-5,24-dien-11-one and 2β,3β,16α,20,25-pentahydroxy-10α-cucurbit-5,23-dien-11-one, mainly by spectroscopy.

Pindrolactone, a new tetracyclic triterpenoid, has been isolated from the leaves of Abies pindrow and its structure advanced as 3α-hydroxylanosta-7,9(11),22E,24-tetraen-26,23-olide.

The structure ofjatamansic acid has been revised from 2D-NMR data, an INADEQUATE experiment and X-ray diffraction analysis. The stereochemistry was con

A sesquiterpene lactone manshurolide with an hitherto unknown carbon skeleton was isolated from Aristolochia manshuriensis. Its structure was elucidated by spectroscopic means and X-ray analysis.

Two new isoflavones, together with quercitrin have been isolated from whole plants of Eschscholtzia californica . The structures of the new isoflavones were determined as 2′-methoxyformononetin and 7-methoxy-2′,4′-dihydroxyisoflavone by spectroscopic methods.

The underground parts of Aristolochia debilis have afforded three new aristolane type sesquiterpenes: 1(1O)-aristolenal-(15), 1α-hydroperoxy-1(10)aristolenone-(2); and 9α-hydroxy-9-aristolenone-(8).

Four sesquiterpene lactones have been isolated from the underground parts of Aristolochia yunnanensis growing in the Yunnan province of China. Three were identified as the known germacranolides costunolide, dehydrocostuslactone and α-cyclocostunolide. The structure of the fourth compound, the non-oxidized melampolide, was elucidated by spectroscopic methods and X-ray analysis.

The previously unknown (+)-isobicyclogermacrenal was isolated from Aristolochia manshuriensis. Its structure was elucidated by spectroscopic means and X-ray analysis.