https://www.rsc.org/suppdata/np/c2/c2np20049j/c2np20049j.pdf

Natural stilbenoids: distribution in the plant kingdom and chemotaxonomic interest in Vitaceae

Natural phenanthrenes and their biological activity.

Biaryls in nature: a multi-facetted class of stereochemically, biosynthetically, and pharmacologically intriguing secondary metabolites.

Six newphenanthrene derivatives, including three monophenanthrenes (1-3), two biphenanthrenes (4 and 5), and a triphenanthrene (6), have been isolated from an ethanolic extract of the tubers of Cremastra appendiculata. Using spectroscopic methods, the structures of compounds 1-6 were determined as 1-hydroxy-4,7-dimethoxy-1-(2-oxopropyl)-1H-phenanthren-2-one (1), 1,7-dihydroxy-4-methoxy-1-(2-oxopropyl)-1H-phenanthren-2-one (2), 2-hydroxy-4,7-dimethoxyphenanthrene (3), 2,7,2'-trihydroxy-4,4',7'-trimethoxy-1,1'-biphenanthrene (4), 2,2'-dihydroxy-4,7,4',7'-tetramethoxy-1,1'-biphenanthrene (5), and 2,7,2',7',2' '-pentahydroxy-4,4',4' ',7' '-tetramethoxy-1,8,1',1' '-triphenanthrene (6), respectively. Compounds 1-6 and two known compounds, cirrhopetalanthin (7) and flavanthrinin (8), obtained previously from this plant, were evaluated against six human cancer cells and a normal cell line.

Mono-, Bi-, and triphenanthrenes from the tubers of Cremastra appendiculata.

Stilbenoids are formed by a particular branch of the flavonoid biosynthetic pathway. They are of special interest to natural product researchers for their roles in plant resistance to fungal pathogens and their biological effects. This review in the volume of Bioactive Natural Products provides a comprehensive account of the occurrence, chemistry, biological roles and activities of the stilbenoids. Nearly 800 stilbenoids, isolated from natural sources in the recent 12 years, are grouped into structural types and discussed in terms of their reported pharmacological activity. The major groups of stilbenoids which are discussed in detail include stilbenes, bibenzyls, bisbibenzyls, phenanthrenoids, stilbene oligomers etc. Detailed tables and figures list the occurrence of stilbenoids in major plant species, and methods used for extracting and analyzing stilbenoids are discussed. Biosynthetic pathways and chemical synthesis are reviewed and the biological activities of stilbenoids are also addressed. The coverage of the new structures is from 1994 to 2006.

Stilbenoids: Chemistry and bioactivities

Thunalbene, a stilbene derivative from the orchid Thunia alba

Bibenzyl derivatives from the orchid Bulbophyllum protractum

Thunalbene, a new stilbene derivative, was isolated from the orchid Thunia alba which also afforded six known stilbenoids: batatasin-III, lusianthridin, 3,7-dihydroxy-2,4-dimethoxyphenanthrene, 3,7-dihydroxy-2,4,8-trimethoxyphenanthrene, cirrhopetalanthrin and flavanthrin. The structure of thunalbene, the first stilbene derivative isolated so far from an Orchidaceae plant, was established as 3,3′-dihydroxy-5-methoxystilbene from spectral and chemical evidence.

S. Chakraborty

Papers

Thunalbene, a stilbene derivative from the orchid Thunia alba

Bibenzyl derivatives from the orchid Bulbophyllum protractum

Thunalbene, a Stilbene Derivative from the Orchid Thunia alba.