Waqar Ahmed

Longifoamide-A and B: Two new ceramides from Mentha longifolia (Lamiaceae)

Two new N-acylsphingosines (ceramides) named longifoamide A {6′-tetracosenamide, (6′-Z)-N-[2,3-dihydroxy-1-(hydroxymethyl)octadecyl]} and B {6′-tetracosenamide, (6′-Z)-N-[2,3,4-trihydroxy-1-(hydroxymethyl)octadecyl]} were isolated from a methanol extract of Mentha longifolia. Both ceramides were characterized with the aid of 1D and 2DNMR spectroscopic techniques and high resolution mass spectrometry.

Longifoside-A and -B: Two new cerebrosides from Mentha longifolia (Lamiaceae)

Two new N-acyl-glycosphingosines (cerebrosides) named longifoside-A {6′-tetracosenamide, N-[3,4-dihydroxy-1-(hydroxymethyl)-2-(β-D-glucopyranosyl) heptadecyl]-(6′E)} and B {6′-tetracosenamide, N-[3-hydroxy-1-(hydroxymethyl)-2-(β-D-glucopyranosyl)-4Z-heptadecenyl]-(6′E)} have been obtained from the methanolic extract of Mentha longifolia belonging to the family Lamiaceae. Both the cerebrosides were purified as their acetate-derivatives: 6′-tetracosenamide, N-[3,4-diacetoxy-1-(acetoxymethyl)-2-(tetraacetoxy-β-D-glucopyranosyl) heptadecyl]-(6′E) and 6′-tetracosenamide, N-[3-acetoxy-1-(acetoxymethyl)-2-(tetraacetoxy-β-D-glucopyranosyl)-4Z-heptadecenyl]-(6′E). They were characterized with the aid of 1D and sophisticated 2D-NMR spectroscopic techniques.

Guaianolide and seco-Guaianolide from Salvia nubicola (Lamiaceae)

A sesquiterpene-lactone of the guaianolide class (nubenone) and a seco-guaianolide (nubenoic acid) have been isolated from Salvia nubicola collected in Quetta, Pakistan. Structures of both sesquiterpenes were elucidated with the aid of spectroscopic techniques including two dimensional NMR spectroscopy.