title: Polyoxypregnane glycosides from Caralluma retrospiciens.
abstract: Six related polyoxypregnane glycosides were isolated and characterised from Caralluma retrospiciens leaves. The compounds were identified as 12beta-benzoyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[3-O-methyl-6-deoxy-beta-D-allopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-]-beta-D-cymaropyranoside], 12beta-benzoyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-allopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-beta-D-cymaropyranoside], 12beta-benzoyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranoside], 12beta-benzoyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranoside], 12beta-benzoyloxy-11alpha-isovaleroyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranosyl-(1 --> 4)-3-O-methyl-6-deoxy-beta-D-galactopyranoside], and 12beta-benzoyloxy-11alpha-isovaleroyloxy-8beta,14beta-dihydroxypregn-20-one-3-O-[beta-D-glucopyranosyl (1 --> 4)-3-O-methyl-6-deoxy-beta-D-allopyranosyl-(1 --> 4)-beta-D-cymaropyranosyl-(1 --> 4)-beta-D-cymaropyranoside]. The structures were determined by detailed analysis of one- and two-dimensional NMR spectra as well as by chemical means. The compounds showed cytotoxic activities towards brine shrimp having IC50 values of 1.19 x 10(-4), 8.83 x 10(-5), 2.64 x 10(-4), 2.26 x 10(-4), 2.39 x 10(-4) and 1.70 x 10(-4) M, respectively. This is the first report of the isolation of these compounds from a natural source.
authors.affiliation: Department of Chemistry and Biochemistry, South Dakota State University, Box 2202 Brookings, SD 57007, USA. fathi_halaweish@sdstate.edu
authors.forename: Fathi T
authors.initials: FT
authors.lastname: Halaweish
authors.forename: Eric
authors.initials: E
authors.lastname: Huntimer
authors.forename: Ashaf T
authors.initials: AT
authors.lastname: Khalil
mesh_terms: D000818:Animals; D029062:Apocynaceae / Q000737:chemistry*; D001156:Artemia / Q000187:drug effects; D002240:Carbohydrate Sequence; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D020128:Inhibitory Concentration 50; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D009904:Optical Rotation; D018515:Plant Leaves / Q000737:chemistry; D011278:Pregnanes / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013055:Spectrophotometry, Infrared
chemical_list: D006027:Glycosides; D011278:Pregnanes