A. S. R. Anjaneyulu

Novel hydroxy lignans from the heartwood of gmelina arborea

Abstract The structures of six new lignans isolated from the heartwood of Gmelina arborea have been determined. They are 6“ - bromo - isoarboreol, 4 - hydroxysesamin, 4,8 - dihydroxysesamin, 1,4 - dihydroxysesamin (gummadiol), 2 - piperonyl - 3 - hydroxymethyl - 4 - (α - hydroxy - 3,4 - methylenedioxybenzyl) - 4 - hydroxytetrahydrofuran, and the 4 - O - glucoside of 4 - epigummadiol. The 1 H and 13 C NMR and mass spectra of these compounds and their derivatives are discussed, and the structure previously assigned to a germination inhibitor from Aegilops ovata is questioned.

Pacharin: a new dibenzo(2,3-6,7)oxepin derivative from bauhinia racemosa lamk

Abstract The isolation of resveratrol and a new dibenzoxepin derivative, pacharin, from the heartwood of Bauhinia racemosa Lank is reported. The structure of pacharin has been established as l,7-dlhydroxy-3-methoxy-2-methyl-dibenzo(2,3-6,7) oxepin (Va) by a study of its chemical and spectroscopic properties, including X-ray analysis.

New lignans from the heartwood of cleistanthus collinus

Abstract The isolation and characterisation of five new compounds and nine known compounds from the heartwood of Cleistanthus collinus are reported. The new compounds are wodeshiol 16 ,3,4-dihydrotaiwanin C 20 , and three new glycosides 24 , 25 and 26 of diphyllin and taiwanin E The 1 H and 13 C NMR spectra of these compounds are also reported.

Two caulerpin analogues and a sesquiterpene from Caulerpa racemosa

Abstract The ethyl acetate extract of Caulerpa racemosa yielded two new red pigments which are caulerpin analogues. A new sesquiterpenoid present was identified as 10-keto-3,7,11-trimethyldodecanoic acid.

The structures of lignans from Gmelina arborea Linn

Five new lignans isolated from Gmelina arborea Linn have been characterised. The parent compound arboreol, is 2a,6e-dipiperonyl-1e,2e-dihydroxy-3,7-dioxabicyclo-[3,3,0]-octane. It is accompanied by its 2-O-methyl ether, the 2-O-ethyl ether and its 2-epimer, isoarboreol,. The fifth substance, gmelanone, is the first reported example of a lignan derived from 3,6-dioxabicyclo-[3,2,1]-octane.

Five diterpenoids (agallochins A-E) from the mangrove plant Excoecaria agallocha Linn.

Chemical examination of the hexane extract of the roots of Excoecaria agallocha Linn collected from the Godavari estuary resulted in the isolation of altogether eleven diterpenoids of which five (1-5) are new. The structures of the new diterpenoids have been elucidated by a study of their physical and spectral (UV, IR, 1H, 13C, DEPT, 1H-1H COSY, NOESY, HMQC, HMBC and MASS) data as 3-oxo-ent-13epi-8(13)-epoxy-15-chloro-14-hydroxylabdane (1), ent-15-chloro-13,14-dihydroxylabd-8(9)-en-3-one (2), ent-15-chloro-labd-8(9)ene-3alpha,13,14-triol (3), ent-11beta-hydroxy-8(14),15-isopimaradien-3-one (4), 8,13-epoxy-3-nor-2,3-seco-14-epilabden-2,4-olide (5). The six known diterpenoids have been characterised respectively as ent-3-oxo-13-epi-manoyl oxide (6), ent-3beta-hydroxy-13-epi-manoyl oxide (7), (13R,14S)-ent-8alpha,13;14,15-diepoxy-13-epi-labdan-3-one (8), ent-16-hydroxy-3-oxo-13-epimanoyl oxide (9), ent-15-hydroxylabda-8(17),13E-dien-3-one (10), labda-8(17),13E-diene-3beta,15-diol (11) by a comparative study of their spectral data with the literature values.

Terpenoid and steroid constituents of the Indian ocean soft coral Sinularia maxima

Abstract The Indian Ocean soft coral Sinularia maxima furnished nine terpenoids (A to D, G to I) and steroids (E and F) which include two new sesquiterpenes (B and C), two 5 α8α-epidioxysterols (E and F) and a novel tetracyclic diterpenoid, isomandapamate (D).

Crystalline constituents of euphorbiaceae—XII: Isolation and structural elucidation of three new lignans from the leaves of Phyllanthus niruri Linn.

Abstract Three more new lignans from the hexane extract of Phyllanthus niruri Linn. are now reported besides phyllanthin and hypophyllanthin. The structure of niranthin is now established as 3,3′,4′,9,9′-pentamethoxy-4,5-methylenedioxy-8,8′-butyrolignan ( 2 ). Nirtetralin and phyltetralin are shown to be 1-phenyl tetralins. On the basis of NMR and mass spectra, nirtetralin is assigned the structure ( 7 ) and phyltetralin ( 11 ).

Chemical examination of the roots of Terminalia arjuna—the structures of arjunoside III and arjunoside IV, two new triterpenoid glycosides☆

Abstract The non-phenolic fraction of the alcoholic extract of the root bark of Terminalia arjuna yielded two new triterpenoid glycosides, arjunoside III and arjunoside IV in addition to arjunglucoside I and arjunetin. The structure of arjunoside III was established as the 28-β- d (+)-glucuronopyranoside of arjunic acid by a study of its chemical and spectroscopic ( 1 H and 13 C NMR) data. Arjunoside IV was shown to be the 3- O -α- l (−)-rhamnoside of arjunic acid. Leucocyanidin, ellagic acid and gallic acid have been isolated from the phenolic part of the root extract.

Rare aromadendrane diterpenoids from a new soft coral species of Sinularia genus of the Indian Ocean

Abstract Chemical examination of a new soft coral species of Sinularia genus of the Indian Ocean resulted in the isolation of 4 new and rare aromadendrane type of diterpenoids, in addition to the known Δ 9(15) - africanene , batyl alcohol and three polyhydroxy steroids. The structures of new diterpenoids have been established by a study of their spectral data. The diterpenoids of this class have now been reported for the first time from a marine organism, while they were reported only once from a terrestrial source. The crude extract of the organism has showed moderate larvicidal activitiy.