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Barterin, a classical cyclopentenoid cyanohydrin glucoside, was shown to be (1S,4S)-1-(β-D-glucopyranosyloxy)-4-hydroxy-2-cyclopentene-1-carbonitrile, being thus identical with tetraphyllin B, contrary to previous statements in the literature.Cyanohydrin glycosides from Adenia dinklagei, A. epigea, A. firingalavensis, A. frutescens, A. hastata, A. letouzeyi, A. spinosa, Passiflora coriacea, P. subpeltata, P. warmingii and Smeathmannia pubescens were isolated and identified.A summary of the present knowledge of distribution of cyanohydrin glycosides in Passifloraceae shows clear differences between the two chief genera, Adenia and Passif lora.Thus, the former genus appears to be dominated by β-D-glucopyranosides of 2-cyclopenten-1-one and 4-hydroxy-2-cyclpenten-1-one cyanohydrin; the glycosides generally occur as pairs having enantiomeric aglycones and the cyclopentene ring is usually trans-1,4-dioxygenated.By contrast, the pattern of cyanohydrin glycosides of Passiflora appears to be highly diversified, comprising valine or isoleucine-derived glycosides as well as cyclopentenoid glycosides, including more elaborate forms than those found in Adenia.The origin of epilotaustralin, possibly arising from the (3R)-epimer of L-isoleucine, is briefly discussed.Key Word Index- Adenia sp.; Passiflora sp.; Smeathmannia sp.; Passifloraceae; barterin; cyclopentenoid cyanohydrin glycosides; linamarin; lotaustralin; epilotaustralin; alloisoleucine.

A novel cyanogenic glycoside, 2-((6-0-(β-D-apiofuranosyl)-β- D-glucopyranosyloxy)-2-methylbutanenitrile, I, three novel non- cyanogenic glycosides, (2S)-((6-0-(β-D-apiofuranosyI)-β-D-gluco- pyranosyloxy) butane, 2; 2-((6-0-(β-D-apiofuranosyl)-β-D-gluco- pyranosyloxy) propane, 3, ethyl p-D-glucopyranosidc, 4, two known cyanogenic glycosides, (R)-2-(β-D-Glucopyranosyloxy)-2- methyl butanenitrile (lotaustralin), 5, 2-(β-D-Glucopyranosyloxy)- 2-methylpropane nitrile (linamarin), 6 have been isolated from ethanolic extract of the fresh rootcortex of Manihot esculenta. Lotaustralin and linamarin and two flavonoid glycosides, kaempferol-3-O- rutinosidc, 7 and quercctin-3-O-rutinoside, 8 have been isolated from the methanol extract of the fresh leaves of the same plant.

Various types of primary amides were treated under an activated dimethyl sulfoxide (DMSO) species, (COCl)2-DMSO and Et3N, as a dehydrating agent to obtain nitriles in excellent yield. This dehydration system was extended to a one-pot preparation of perfluoroimidates via volatile perfluoronitriles from perfluoroamides. Fifteen benzyl-type perfluoroimidates can be prepared in 70-90% yield as more stable imidates than the trichloro analogue. MPM- and DMPM-perfluoroimidates can be used to protect alcohols in place of the trichloroacetimidate with excellent chemical properties and in comparable yields.

A facile synthetic route is described to cyanogenic glycosides (R)-prunasin, linamarin and (S)-heterodendrin from O-(2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl)trichloroacetimidate and the corresponding α-hydroxyamides by a 3-step reaction of glycosylation, cyanohydrin formation by dehydration of carboxamides, and deprotection.

In addition to lotaustralin and linamarin, a novel cyanogenic glycoside, 2-((6-O-(β-D-apiofuranosyl)-β-D-glucopyranosyl)oxy)-2-methylbutanenitrile, two novel non-cyanogenic glycosides, (2S)-((6-O-(β-D-apiofuranosyl)-β-D-glucopyranosyl)oxy)butane and 2-((6-O-(β-D-apiofuranosyl)-β-D-glucopyranosyl)oxy)propane, and a simple non-cyanogenic glycoside, ethyl β-D-glucopyranoside, were isolated from an ethanolic extract of the fresh root cortex of manihot esculenta.From a methanolic extract of the fresh leaves of this species lotaustralin and linamarin, and two flavonoid glycosides, kaempferol-3-O-rutinoside and quercetin-3-O-rutinoside were isolated. - Keywords: Manihot esculenta; Euphorbiaceae; cassava; roots; leaves; cyanogenic glycosides; non-cyanogenic glycosides; flavonoids.