K.L. Dhar

Revised structures of daturalactone and 12-oxowithanolide

Abstract Recently Dhar et al. reported the isolation of two new steroidal lactones from the leaves of Datura quercifolia HBK and formulated them as 5α,12α,17α-trihydroxy-1-oxo-6α, 7α-epoxy-22 S -witha-2,24-dienolide and 5α,17α-dihydroxy-1, 12-dioxo-6α,7α-epoxy-22 S -witha-2,24-dienolide on the basis of UV, IR, NMR and MS studies. Further detailed chemical and spectral studies have led to revised structures, namely 5α, 12α-dihydroxy-1-oxo-6α,7α: 24α, 25α-diepoxy-20 S , 22 R -with-2-enolide and 5α-hydroxy-1, 12-dioxo-6α, 7α: 24α, 25α-diepoxy-20 S , 22 R -with-2-enolide, respectively, for the above two compounds.

Two isoflavones from Iris kashmiriana

Abstract 3′-Hydroxy- and 4′-hydroxy-5,5′-dimethoxy-6,7-methylene-dioxyisoflavones were identified in the rhizomes of Iris kashmiriana .

28-Noroleana-16,21-diene triterpenes from Phlomis spectabilis

Abstract Two new nortriterpenes have been isolated from Phlomis spectabilis and characterised as 28-noroleana-16,21-diene-3α,19α,23,29-tetrol and 28-noroleana-16,21-diene-3α,19α,29-triol-23-al.

Triterpenoids from Swertia petiolata

Abstract From the petrol extract of Swertia petiolata a new natural triterpene, 3β-hydroxylup-13(18)-ene has been isolated in addition to 3β-hydroxylup-12en-28-oic acid and ursolic acid.

A cinnamoyl pyrrolidine amide from Piper peepuloides

Analysis of a petrol extract of the leaves of Piper peepuloides resulted in the isolation of a new cinnamoyl pyrrolidine amide characterized as Z-pyrrolidine-1-3-(6-methoxy-1,3-benzodioxol-5-yl)-1-oxo-2-propenyl along with peepuloidin, 2-methoxy-4,5-methylenedioxy-Z-cinnamoyl piperidide, β-sitosterol and β-sitosterol glucoside.

Isomeric 2,3-seco-hopene lactones from Swertia petiolata

Abstract Two novel isomeric hopene triterpenes, Swertialactone C and Swertialactone D have been isolated from Swertia petiolata. Their structures were established as 2,3-seco-2 → 3 lactone, 1β,3β-epoxy-hop-17(21)-ene and 2,3-seco-2 → 3 lactone, 1β,3β-epoxy-hop-16-ene, respectively.