C.K. Atal

Lignans of Piper clusii

Abstract From the petrol extract of Piper clusii five lignans were isolated. One of the lignans (−)-clusin is assigned the structure (−)-2-furanol-4(1,3-benzodioxol-5-ylmethyl) tetrahydro-3(3,4,5-trimethoxyphenyl) methyl. This is the first report of this compound from a natural source. Asaronaldehyde and sitosterol were also present.

Flavonoids of andrographis paniculata

Abstract Chromatographic separation of the petrol extract of Andrographis paniculata roots resulted in the isolation and characterization of two new flavonoids, 5-hydroxy-7,8-dimethoxyflavanone and 5-hydroxy-3,7,8,2′-tetramethoxyflavone, as well as the known flavonoid 5-hydroxy-7,8-dimethoxyflavone.

Two unsymmetric tetracyclic triterpenoids from Cissus quadrangularis

Abstract Two new unsymmetric tetracyclic triterpenoids onocer-7-ene-3α,21β-diol and onocer-7-ene-3β,21α-diol together with sitosterol, δ-amyrin and δ-amyrone have been isolated from Cissus quadrangularis . The structures of the new compounds were elucidated on the basis of 1 H NMR, mass spectral and chemical evidence.

Vasicol, a new alkaloid from Adhatoda vasica

Abstract A novel alkaloid isolated from the roots of Adhatoda vasica has been characterized as 1,2,3,4,9,11 hexahydro pyrrolo (2,1-b) quinazolin-3,11 diol by chemical and spectroscopic methods. Vasicinone has also been isolated from the roots of this plant.

(−)-Epiafzelechin 5-O-βD-glucoside from crataeva religiosa

Abstract Epiafzelechin 5-glucoside was characterized from the bark of Crataeva religiosa together with other known compounds.

Isoflavones and stilbenes from Juniperus macropoda

Abstract An ethanolic extract of Juniperus macropoda , after chromatography, yielded three isoflavones, viz.irigenin, iridin and a new compound. In addition two stilbenes, resveratrol and piceid (resveratrol-3- O -β- D -glucoside), were isolated and characterized.

Two isoflavones from Juniperus Macropoda

Abstract Two new isoflavones, junipegenin-B and -C, have been isolated from ethanolic extracts of Juniperus macropoda and their structures assigned. One of them, junipegenin-C, has been synthesized from iridin.

Minor lignans of Piper clusii

Abstract Further investigations on the petrol extract of Piper clusii have afforded four more new lignans.These are 2 S ,3 R ,4 R ,2-ethoxy-3-(3,4,5-trimethoxyphenyl)methyl 4-(1,3-benzodioxol-5-yl) methyl tetrahydrofuranol; 3 R ,4 R , bis -3,4-(3,4,5-trimethoxyphenyl) methyl tetrahydrofuran-2-one; 2 R ,3 R ,2-(7-methoxy-1,3-benzodioxol-5-yl) methyl 3-(3,4,5-trimethoxyphenyl)methyl butan-1,4-diol and 2 R ,3 R ,2-(1,3-benzodioxol-5-yl)methyl 3-(3,4,5-trimethoxyphenyl) methyl butan-1,4-diol. This is the first report of these compounds from a natural source.

A C-formylated azulene from Lactarius deterrimus

Abstract 1-Formyl-4-methyl-7-isopropyl azulene (11,12-dihydro-lactaroviolin) was characterized from Lactarius deterrimus together with other known compounds.

Three isoflavone-glycosides from juniperus macropoda

Abstract Three new isoflavone glycosides have been characterized from the leave of Juniperus macropoda : 5,7-dihydroxy-6,3′,4′-trimethoxyisoflavone 7-glucoside; 5,7,4′-trihydroxy-6,3′,5′-trimethoxyisoflavone 7-glucoside and 5,7,3′-trihydroxy-6,4′-dimethoxyisoflavone 7-diglucoside.