New Iridoids from Gelsemium Species

New iridoids from Gelsemium species.

Four new iridoids structurally related to gelsemide (5) were isolated from two Loganiaceous plants, Gelsemium elegans and G. rankinii. Among them, GEIR-1 (1) has a novel tetracyclic caged structure.

Two new iridoids from Verbena officinalis L.

Two new iridoids, 3-(5-(methoxycarbonyl)-2-oxo-2H-pyran-3-yl)butanoic acid, named verbeofflin I (1), and 7-hydroxydehydrohastatoside (2), were isolated from the aerial part of Verbena officinalis L, along with three known iridoids, verbenalin (3), 3,4-dihydroverbenalin (4), hastatoside (5) by means of various column chromatography steps. The structures of these compounds were elucidated through...

Gelsemium alkaloids, immunosuppressive agents from Gelsemium elegans.

Bioassay-guided isolation of the stems of Gelsemium elegans has led to the isolation of two new Gelsemium alkaloids, 21-(2-oxopropyl)-koumine (1) and 11-methoxygelselegine (2), and two known alkaloids, koumine (3) and gelselegine (4). The structures of 1-2 were determined by spectroscopic (for both) and single-crystal X-ray diffraction (for 1) analysis. All compounds isolated were evaluated for...

Iridoids of guyanese species of stigmaphyllon.

Iridoids from Avicennia marina.

Three new iridoid glucosides, 10-O-[(E)-cinnamoyl]-geniposidic acid, 10-O-[(E)-p-coumaroyl]-geniposidic acid, 10-O-[(E)-caffeoyl]-geniposidic acid and the known iridoid glucoside, 2'-O-[(E)-cinnamoyl]-mussaenosidic acid have been isolated from Avicennia marina. The structures were determined primarily by NMR spectroscopy. The assignment of NMR signals was performed by means of 1H-1H COSY, HMQC ...