Protostrychnine,a new alkaloid from Strychnos nux-vomica

The tertiary bases from a sample of Strychnos nux-vomica contain, as well as the expected strychnine and brucine, an unusually high proportion of 4-hydroxy and 4-hydroxy-3-methoxy compounds. The biosynthetic implications of the isolation of a new alkaloid, 12β,13α-dihydro-12α-hydroxyisostrychnine, named protostrychnine, are discussed.     

Glycarpine,a new alkaloid from Glycosmis cyanocarpa

Glycarpine, a new furoquinolone alkaloid and evolitrine have been isolated from Glycosmis cyanocarpa.     

Megistolactone, a new alkaloid from Sarcomelicope megistophylla

A new quinolone alkaloid, megistolactone (1) was isolated from the bark of Sarcomelicope megistophylla. Its structure has been elucidated on the basis of MS and NMR data. From a biogenetic point of view, this compound should be considered as an oxidation product of 1,2,3,4-tetra-O-subsituted acridone alkaloids, which are also present in the bark.     

昆虫的体外化学防卫物质简介

本文介绍了昆虫体外防御物质的释放部位、来源、化学成分及影响其释放的因素等的研究进展。     

Parvine,a new angustine-type alkaloid from Nauclea parva

The bark of Nauclea parva contains several alkaloids, the most abundant of which, parvine, is of the corynanthé-type. The proof of structure of this alkaloid is given and its synthesis from harmalan and nicotinoyl chloride is described.     

Piplartine-dimer A,a new alkaloid from Piper tuberculatum

Piplartine-dimer A (1), a dimer of the known pyridone alkaloid piplartine, was isolated from root bark of Piper tuberculatum. It is accompanied by piplartine (3) and 3,4,5-trimethoxycinnamic acid.     

Steviamine,a new indolizidine alkaloid from Stevia rebaudiana

The novel iminosugar (1R,2S,3R,5R,8aR)-3-(hydroxymethyl)-5-methyloctahydroindolizine-1,2-diol (steviamine) was isolated from leaf material of Stevia rebaudiana and leaves and bulbs of Veltheimia capensis. This is the first report of an indolizidine iminosugar alkaloid from the Asteraceae and Hyacinthaceae. Steviamine may occur in some Stevia products and influence taste.     

Nupharopumiline,a new quinolizine alkaloid from Nuphar pumila

A new quinolizine alkaloid, (+)-nupharopumiline, has been isolated from the rhizomes of Nuphar pumila. It has been shown by spectroscopic and chemi     

Iso-erysopinophorine,a new quaternary alkaloid from the seeds of Erythrina arborescens

The ethanolic extract of the seeds of Erythrina arborescens yielded a new quaternary alkaloid provisionally named as iso-erysopinophorine besides the other alkaloids reported previously. The new alkaloid was characterised by chemical and spectral studies.     

Emiline,a new alkaloid from the aerial parts of Emilia sonchifolia

A new pyrrolidine alkaloid, Emiline (1), was isolated from the 90% EtOH extract of the aerial parts of Emilia sonchifolia. Its structure was established by various spectroscopic methods, including NMR, IR, HR-ESI-MS and X-ray crystallography. It was characterized by its skeleton derived from a bicyclo-[2.2.2]-oct-5-one ring and a pyrrolidine unit. The racemic mixture, (±)-Emiline, displayed good neuroprotective effect against the corticosterone-induced apoptosis in PC12 cells.