Bulbophyllanthrin, a novel phenanthrene derivative from the orchid Bulbophyllum leopardium, was shown to have the structure 1a mainly on the basis of spectral evidence including 13C and 2D NMR spectra. © 1985.

P L MAJUMDER

A KAR

J N SHOOLERY

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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Bulbophyllanthrin, a phenanthrene of the orchid Bulbophyllum leopardium

Phytochemistry

Reptanthrin and isoreptanthrin, two new dimeric phenanthrenes, were isolated from the orchid Bulbophyllum reptans which also afforded nine known stilbenoids, viz. gymnopusin (1a) [2,7-dihydroxy-3,4,9- trimethoxyphenanthrene], confusarin (1c) [2,7-dihydroxy-3,4,8- trimethoxyphenanthrene], 2,7-dihydroxy-3,4,6-trimethoxyphenanthrene (1d) and its 9,10-dihydro derivative, flavanthrinin (1e) [2,7-dihydroxy-4- methoxyphenanthrene] and its 9,10-dihydro derivative (coelonin), 3,3'- dihydroxy-5-methoxybibenzyl (batatasin-III), cirrhopetalanthrin (2a) [2,2',7,7'-tetrahydroxy-4,4'-dimethoxy-1,1'-biphenanthryl] and its 9,9',10,10'-tetrahydro derivative (flavanthrin). The structures of reptanthrin and isoreptanthrin were established as 2,2',7,7'-tetrahydroxy- 3,3',4,4',9,9'-hexamethoxy-1,1'-biphenanthryl (2c) and 2,2',7,7'- tetrahydroxy-3,3',4,4',9,9'-hexamethoxy-1,8'-biphenanthryl (3a), respectively, from spectral and chemical evidence including their biomimetic synthesis from the congener 1a with phosphomolybdic acid (PMA) on silica gel.

Dimeric phenanthrenes from the orchid Bulbophyllum reptans

Rotundatin, a new 9,10-dihydrophenanthrene derivative was isolated from the orchid, Dendrobium rotundatum, which also afforded the known stilbenoids 2,7-dihydroxy-3,4,6-trimethoxyphenanthrene, 2,7-dihydroxy-3,4,6-trimethoxy-9,10-dihydrophenanthrene, nudol, moscatin and batatasin-III. Rotundatin was shown to be 2,5,9-trihydroxy-4-methoxy-9,10-dihydrophenanthrene from spectral and chemical evidence. © 1992.

Rotundatin, a new 9,10-didydrophenanthrene derivative from Dendrobium rotundatum

Isoflaccidinin and isooxoflaccidin, new phenanthropyrone derivatives, isolated from the orchid Coelogyne flaccida were shown to be 2,7-dihydroxy-6-methoxy-5H-phenanthro [4,5-bcd] pyran-5-one and 2,7-dihydroxy-6-methoxy-9,10-dihydro-5H-phenanthro [4,5-bcd] pyron-5-one, respectively, from spectral and chemical evidence. © 1992.

Isoflaccidinin and isooxoflaccidin, stilbenoids from Coelogyne flaccida

From the orchid Cymbidium pendulum were isolated, besides the previously reported 3,7-dihydroxy-2,4,8-trimethoxyphenanthrene, a new phenanthrene derivative, pendulin. While the structure of the former was further confirmed by its 13C NMR spectral data, that of the latter was established as 3-hydroxy-2,4,6,7,8-pentamethoxyphenanthrene from spectroscopical chemical evidence. © 1991.

Pendulin, a polyoxygenated phenanthrene derivative from the orchid Cymbidium pendulum

A new phenanthraquinone, bulbophyllanthrone was isolated together with the known flavonoids chrysin and pinobanksin from the orchid Bulbophyllum odoratissimum. The structure was established mainly from spectroscopic evidence. © 1991.

Bulbophyllanthrone, a phenanthraquinone from Bulbophyllum odoratissimum

Cyclootochilone and otochilone, two novel steroidal ketones of the orchids Otochilus porecta were shown to have the structures 1a and 2, respectively, from spectral and chemical evidence, 1a alone has also been obtained from the taxonomically related orchid Otochilus fusca. The significance of these compounds in the biogenetic transformation of lanosterol to steroids and the biogenetic sequence of the origin of 9,19- cyclopropane ring present in some terpenoids and steroids, as well as the mechanism of incorporation of two methyl groups at C-24 of some of these compounds were discussed. © 1985.

Tetrahedron

Structures of cyclootochilone and otochilone, two novel steroidal ketones of the orchids otochilus porecta and otochilus fusca

An amorphous phenanthrene, named nudol has been isolated from Eulophia nuda, Eria carinata and E. stricta. It was identified as 2,7-dihydroxy-3,4-dimethoxyphenanthrene. Synthesis of nudol and its dimethyl ether is described. © 1985.

Nudol, a phenanthrene of the orchids Eulophia nuda, Eria carinata and Eria stricta

Oxoflavidin, a new phenolic compound isolated from the Himalayan orchid Coelogyne elata was shown to be 2,7-dihydroxy-9,10-dihydro-5H-phenanthro[4,5-bcd]pyran-5-one (2d) by spectral and chemical evidence. © 1984.

Structure of oxoflavidin, a 9,10-dihydrophenanthropyrone from Coelogyne elata

Coelonin, A 9,10-dihydrophenanthrene from the orchids Coelogyne ochracea and Coelogyne elata

The structure of flavidin (1a), a modified 9,10-dihydrophenanthrene, isolated from the orchids Coelogyne flavida, Pholidota articulata and Otochilus fusca has been established on the basis of spectral data. © 1982, American Chemical Society. All rights reserved.

Journal	Phytochemistry
Publisher	-
ISSN	0031-9422