Naveen K. Khare

Two pregnane ester glycosides from Pergularia pallida

Abstract Two new pregnane ester glycosides designated as pallidine and pallidinine have been isolated from the dried twigs of Pergularia pallida . Chemical and spectroscopic evidences are consistent with the structure 12,20-di- O -benzoyl sarcostin-3- O -β- d -oleandroside and 12,20-di- O -benzoyl-sarcostin-3- O -β- d -cymaropyranosyl(1 → 4)-β- d -oleandropyranoside for pallidine and pallidinine respectively.

Two oligosaccharides from Marsdenia roylei

Phytochemical analysis of dried twigs of Marsdenia roylei (family Asclepiadaceae) has resulted in the isolation of a trisaccharide, maryal, and a diglycoside, rolinose. Their structures were determined as O-beta-D-oleandropyranosyl-(1-->4)-O-beta-D-digitoxopyranosyl++ +-(1-->4)-D- cymaral and ethyl O-beta-D-oleandropyranosyl-(1-->4)-O-3-O-methyl-6-deoxy-beta-D- allopyranoside, respectively, by chemical degradation and spectroscopic methods.

Pregnanes and pregnane glycosides from Marsdenia roylei

Two pregnanes namely desacylkondurangogenin C (1) and deniagenin (3, new) and two new pregnane glycosides designated as denin (5) and marsin (12) have been isolated from chloroform soluble extract of dried stem of Marsdenia roylei. Chemical and spectroscopic evidences are consistent with the structures of deniagenin, denin and marsin as 3beta, 11alpha, l2beta, 14beta, 17beta, 20-hexahydroxy pregn-5-ene; desacylkondurangogenin C-3-O-alpha-D-glucopyranosyl-(1-->4)-O-alpha-L-fucopyranoside and ketocalogenin-3-O-alpha-L-fucopyranoside, respectively.

Trisaccharides from Marsdenia roylei

The structures of two novel trisaccharides viz. royleose and deniose isolated from Marsdenia roylei were elucidated with the help of modern physico-chemical techniques and chemical transformations. They were defined as O-beta-D-oleandropyranosyl-(1-->4)-O-beta- D-cymaropyranosyl-(1-->4)-beta-D-oleandropyranose and O-beta-D-oleandropyranosyl-(1-->4)-O-beta-D-digitoxopyranosyl++ +-(1-->4)- beta-D-oleandropyranose respectively. This is the first report on the isolation of trisaccharides of rare deoxy sugars in free state from nature.

A new pregnane glycoside from Marsdenia roylei as potential antioxidant and antidyslipidemic agents

A new pregnane glycoside roylenine (1) was isolated from the CHCl3–EtOH (4:1) extract of Marsdenia roylei. Its structure was established on the basis of spectroscopic studies. The glycoside (1) and its acetylated derivative (6) were evaluated for their antioxidant and antidyslipidemic activities.

Sarcogenin, a pregnane derivative from Pergularia pallida and Sarcostemma brevistigma

Abstract A new pregnane genin, designated as sarcogenin has been isolated from Pergularia pallida and Sarcostemma brevistigma and characterized as 3β,8β,11α,12β,14β,17β-hexahydroxypregn-5-en-20-one.

Structure of digoxose

Abstract A new trisaccharide, named digoxose, has been isolated from the dried twigs of Orthenthera viminea (Family: Asclepiadaceae). On the basis of chemical and spectroscopic evidence, the structure of this new trisaccharide has been established as O -β- d -digitoxopyranosyl-(1→4)- O -β- d -digitoxopyranosyl-(1→4)-α- d -digitoxopyranose.

Pregnane and pregnane tetraglycoside from Marsdenia roylei

Pregnane oligoglycoside, namely roylinine (1), and a pregnane derivative, namely marsgenin (11), have been isolated from chloroform-soluble extract of dried stem of Marsdenia roylei, and their structures were determined using 1H-NMR, 13C-NMR, 1H-1H COSY, HSQC, TOCSY and FABMS spectral techniques as well as chemical degradation and derivatisation.

Two pregnane oligoglycosides from Marsdenia roylei

The structure of pregnane oligoglycosides, namely rocinine (1) and marsdinine (11), which have been isolated from the chloroform soluble extract of the dried stem of Marsdenia roylei, were elucidated using MS, 1H NMR, 13C NMR, 1H–1H COSY, HSQC and TOCSY experiments as well as chemical degradation and derivatisation.

Two novel steroidal derivatives from chloroform-soluble extract of Hoya longifolia.

The structures of two novel steroidal derivatives (1 and 4) were elucidated. Steroidal derivatives namely fologenin (1) and hoyagenin (4) have been isolated from chloroform-soluble extract of the whole plant of Hoya longifolia (family: Asclepiadaceae), and their structures were determined by using 1H NMR, 13C NMR, 1H–1H COSY and FAB-MS techniques as well as chemical degradation and derivatisation.