H.A. Hassanean

Iridoid and megastigmane glycosides from Phlomis aurea

From the leaves of Phlomis aurea, two new iridoids of unique structures named 3-epiphlomurin (1) and phlomurin (2), a new megastigmane glucoside phlomuroside (3) and a new benzyl alcohol glycoside having the structure benzyl alcohol-O-beta-xylopyranosyl-(1-->2)-beta-glucopyranoside (4) have been isolated together with four known iridoids auroside, lamiide, 8-epiloganin and ipolamiide, two known phenolic glycosides acteoside (verbascoside) and syringin, one known phenylethanoid glycoside 2-phenylethyl-O-beta-xylopyranosyl-(1-->2)-beta-glucopyranoside, one known lignan liriodendrin and three known flavonoids chrysoeriol-7-O-beta-glucopyranoside, acacetin-7-O-beta-glucopyranoside and luteolin-7-O-beta-glucopyranoside. The structures of the isolated compounds were verified by means of mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectral analyses.

An acylated isorhamnetin glucoside from Zygophyllum simplex

Abstract From the aerial parts of Zygophyllum simplex a new glycoside was isolated and identified as 6″-(2- E -butenoyl) isorhamnetin-3- O -glucoside in addition to the known compounds: isorhamnetin, isorhamnetin 3- O -glucoside, kaempferol 3- O -rutinoside, sitosterol glucoside and quinovic acid 3-α- l -rhamnoside. The structures of the isolated compounds were elucidated by spectral analysis.

14-decarboxyquinovic and quinovic acid glycosides from Zygophyllum album

Further investigation of the leaves and stems of Zygophyllum album afforded four triterpene glycosides which were characterized as 14-decarboxyquinovic acid-3 beta-O-beta-D-quinovopyranosyl (1-->4)-quinovopyranoside, quinovic acid 28-O-beta-D-glucopyranosyl (2-->1)beta-D-glucopyranosyl ester, quinovic acid 27-O-beta-D-glucopyranosyl(2-->1)beta-D-glucopyranosyl ester and quinovic acid-3-beta-O-glucopyranosyl(2-->1)rhamnopyranoside. In addition, two flavonoid glycosides were isolated. The structures of the isolated compounds were established by GC, GC-MS, mass spectra, 1H and 13C NMR.

Peculiar side-chain fission of steroidal glycosides

The characteristic novel steroidal glycosides of the 23,26-oxygenated spirostanol-type and 16,22-dicarbonyl cholestanol-type obtained in our laboratory underwent the peculiar reactions of side-chain fission between C-22 and C-23 of the steroidal skeleton by acid or alkaline hydrolysis. These reactions would be applied to the structural determination of these sorts of glycosides and suggest the biogenetic pathway of the occurrence of C-22 lactone-type glycosides.

Saikosaponins from Taverniera aegyptiaca

Abstract By tracing the UV triplet of heteroannular dienes, three novel saikosaponins were isolated from the root bark of Taverniera aegyptiaca. They were identified as 22β-hydroxyolean-11,13(18)-dien-3β-yl-β- d -glucopyranoside, 1β,22β-dihydroxyolean-11,13(18)-dien-3β-yl-β- d -glucopyranoside and 1β,22β-dihydroxyolean-11,13(18)-dien-3β-yl-β- d -xylopyranosyl(1 → 2)β- d -glucopyranoside on the basis of chemical and spectral evidences.

A new oleanene triterpene from Gladiolus segetum Ker-Gawl

A new pentacyclic oleanene triterpene, 2β, 3β, 16α, 28-tetrahydroxy-olean-12-ene-23-oic acid (1), as well as the known pentacyclic triterpene medicagenic acid (2), have been isolated by different chromatographic techniques from the acid hydrolysate of the saponin fraction of Gladiolus segetum. The identification of these compounds was established by different methods of physical, chemical and spectral evidence.

Evaluation of Secondary Metabolites from the Red Sea Tunicate Polyclinum Constellatum

Abbreviations: 1H NMR, proton nuclear magnetic resonance; 13C NMR, carbon nuclear magnetic resonance; 2D, two dimension; δ, chemical shifts; s, singlet; d, doublet; dd, doublet of doublet; t, triplet; m, multiplet; J, coupling constant; Hz, hertz; HRESIMS, high resolution electrospray ionization mass spectrometry; GC/ MS, gas chromatographic mass spectrometry; m/z, mass to charge ratio; MeOH, methanol; EtOAc, ethyl acetate; CH2Cl2, methylene chloride; CHCl3, chloroform; HCl, hydrochloric acid; DFMO, α-difluoromethylornithine; Ac, acetyl; min, minute(s); h, hour(s) THP-1, human monocytic cell line derived from an acute monocytic leukemia patient; IC50, concentration that afford 50% inhibition; IC90, concentration that afford 90% inhibition