A.K. Barua

Flavonoid constituents of Eupatorium odoratum

Abstract Isosakuranetin and a new chalcone, odoratin, have been isolated from the leaves of Eupatorium odoratum . The structure of odoratin has been shown to be 2′-hydroxy-4,4′,5′,6′-tetramethoxy chalcone.

Phaseoloidin, a homogentisic acid glucoside from Entada phaseoloides

Abstract The structure of phascoloidin isolated from the seeds of Entada phaseoloides has been determined as homogentisic acid 2- O -β- d -glucopyranoside by chemical and spectral means.

Clausenalene, a carbazole alkaloid from Clausena heptaphylla

Abstract A new carbazole alkaloid designated as clausenalene was isolated from the stem bark of Clausena heptaphylla and its structure established as 3-methyl-6,7-methylenedioxy carbazole from physical, chemical evidence and synthesis. This is the first report of a methylenedioxy carbazole alkaloid from a plant source.

The structure and stereochemistry of a triterpene acid from lantana camara

Abstract The structure of lantoic acid, a new triterpene isolated from the leaves of Lantana camera, has been determined as 3,25-epoxy-3α,22β-dihydroxy-ursa-12-ene-28-oic acid by chemical and spectroscopic means.

The structure and stereochemistry of phlogantholide-A, a diterpene from Phlogacanthus thyrsiflorus

Abstract The structure and stereochemistry of phlogantholide-A, a new diterpene lactone isolated from the leaves of Phlogacanthus thyrsiflorus has been determined as 2β,15,18-trihydroxy- ent -labd-8(17),13-dien-16-oic lactone by chemical and spectroscopic means.

The structure and stereochemistry of lantanilic acid, the β,β-dimethylacryloyl ester of lantaninilic acid, isolated from Lantana camara

Abstract The structure of lantanilic acid, a new triterpene isolated from the leaves of Lantana camara , has been determined as the β,β-dimethylacryloyl ester of lantaninilic acid.

Phloganthoside—a diterpene lactone glucoside from Phlogacanthus thyrsiflorus

Abstract A new diterpene glucoside, phloganthoside, has been isolated from Phlogacanthus thyrsiflorus and its structure has been established as phlogantholide-A-19- O -β- d -glucopyranoside.

Spergulacin-A: a triterpenoid saponin from Mollugo spergula

Abstract From Mollugo spergula a new triterpenoid saponin, spergulacin-A, has been isolated and its structure established as spergulagenin-A-3- O -[α- L -rhamnopyranosyl-(1 → 2)]-β- D -xylopyranoside.

The structure and stereochemistry of barrigenic acid, a new triterpene acid sapogenin from Barringtonia acutangula

Abstract A new triterpene acid, barrigenic acid, was isolated from the fruits of Barringtonia acutangula . Its structure was established as 2α,3β,19β-trihydroxyolean-12-en-23,28-dioic acid.

Cymbinodin-A, a phenanthraquinone from Cymbidium aloifolium

Abstract Cymbinodin-A has been isolated from the orchid Cymbidium aloifolium and its structure has been established as 5-hydroxy-3-methoxy-1,4-phenanthraquinone. Friedelin and sitosterol have also been found in the plant.