Common Plant Constituents Research Articles

A cyperane and trixanes from Jungia polita

Aerial parts of Jungia polita afforded 8α-hydroxycyperotundone, a nortrixane, a trixane and a known guaiane as well as salvigenin, pectotinarigenin, pinoresinol and other common plant constituents.

A cadinanolide and other sesquiterpene lactones from Mikania haenkeana

Extraction of the aerial parts of Mikania haenkeana afforded four heliangolides, one of them known, one known germacradienolide, a new guaianolide and a new cadinanolide related to arteannuin B, as well as known ent-kauranes and other common plant constituents. Structures of two of the compounds described in the literature are revised.

Glaucolides and related sesquiterpene lactones from Vernonia nudiflora and Chrysolaena propinqua

Aerial parts of Vernonia nudiflora furnished glaucolides A and B, one known and one new glaucolide derivative, one known and three new hirsutinolide derivatives and two new cadinanolides as well as several flavonoids and other common plant constituents. Aerial parts of Chrysolaena propinqua gave glaucolide B, one known and one new hirsutinolide and common plant constituents.

Sesquiterpene lactones and other constituents of Mikania rimachii and Mikania microptera

Extraction of the aerial parts of Mikania rimachii afforded a new dihydrooxepine type elemadienolide, a rare triterpene, 3′,4-dihydroxy-3-methoxypropiophenone, and various common plant constituents. The aerial parts of Mikania microptera furnished four new dihydrooxepine type elemadienolides, seven new melampolides, a new nerolidol derivative as well as nerolidol itself, 5-hydroxymethyl-2-furfuraldehyde and various common plant constituents. Structures of the new substances were investigated by high field NMR techniques and chemical transformations. In the case of one of the melampolides, the structure was confirmed by an X-ray analysis. The stereochemistry of the biological divinyloxirane-dihydrooxepine rearrangement is discussed.

Monoterpenes and Lignans from Mikania saltensis

l-he aerial parts of Mzkania saltensis yielded, in addition to common plant constituents, two menthane derivatives 1 and 2 new as natural products, pinoresinol, and a new lignan, (1R',2S+,5R*,bS1)-2-~4-hydroxyphenyl)-6-~3-methoxy-4-hydroxyphenyl)-3,7-dioxabi- cyclo(3.3.O)octane 151.

Isoflavones, a sesquiterpene lactone-monoterpene adduct and other constituents of Gaillardia species

Aerial parts of Gaillardia suavis gave orobol 7,3′-dimethyl ether and the new isoflavones 7,3′-dimethoxy-5,6,4′-trihydroxyisoflavone and 7-methoxy-5,6,4′-trihydroxyisoflavone. Gaillardia aestivalis from central Texas gave the 2′-acetylglucopyranosides of 12-hydroxynerolidol and 10,11-dihydro-12-hydroxynerolidol and the 2′,6′-diacetylglucopyranoside of 2-phenethyl alcohol as well as some common plant constituents, while the main constituent of several other G. aestivalis collections was a Diels—Alder adduct of multigilin and 8-hydroxy-α-phellandrene.

Glaucolides and related sesquiterpene lactones from Vernonia incana

Chemical investigation of Vernonia incana resulted in isolation of glaucolide A, two ester analogues and two new glaucolide precursors as well as common plant constituents.

Guaianolides and other constituents from Vernonia nitidula

Chemical investigation of Vernonia nitidula resulted in isolation of 11 guaianolides, eight of them new, as well as other common plant constituents.

Sesquiterpene lactones and other constituents of Arnica acaulis

Chemical investigation of the aerial parts of Arnica acaulis resulted in isolation of 12 known helenanolides, one new melampolide baileyin acetate and the transfused guaianolides florilenalin acetate and 11 α H, 13dihydroflorilenalin acetate as well as other relatively common plant constituents. The implications for the biogenesis of helenanolides and the chemotaxonomic situation in Arnica are discussed.

Trixane derivatives from Trixis praestans

Chemical Investigation of Trixis praestans resulted in isolation of several new sesquiterpene diesters of the trixane type as well as common plant constituents.

Glaucolides and related sesquiterpene lactones from Vernonia chamaedrys

Chemical investigation of the aerial parts of Vernonia chamaedrys resulted in the isolation of 15 glaucolides and related sesquiterpene lactones, six of them new, as well as a number of common plant constituents. The C-8 stereochemistry of the piptocarphins is corrected.