A new cyanogenic glycoside from Hordeum vulgare

From leaf extracts of 10-day-old seedlings of barley, a new cyanogenic glycoside has been isolated. This compound is 2-β-d-glucopyranosyl-oxy-3-methyl-(2R )-butyronitrile, the epimer of heterodendrin.     

Two cyanogenic glucosides,tetraphyllin B and epi-tetraphyllin B,from Adenia volkensii

Tetraphyllin B and its previously unknown epimer have been isolated from the Kenyan plant Adenia volkensii. The structures were established by their NMR spectra and by GLC.     

Passibiflorin,epipassibiflorin and passitrifasciatin: cyclopentenoid cyanogenic glycosides from Passiflora

An epimeric mixture of two novel cyclopentenoid cyanogenic glycosides, passibiflorin [1-(6-O-β-D-rhamnopyranosyl-β-D-glucopyranosyloxy)-4-hydroxycyclopent-2-en-1-nitrile] and its C-1 epimer, epipassibiflorin, has been isolated from Passiflora biflora and P. talamancensis. The structures were determined by means of ¹H NMR and ¹³C NMR. Another novel cyclopentenoid cyanogenic glycoside, passitrifasciatin [1-(4-O-β-D-rhamnopyranosyl-β-D-glucopyranosyloxy)-4-hydroxycyclopent-2-en-1-nitrile] is described from Passiflora trifasciata. The structure was determined by means of ¹H NMR. The identification of the sugar moieties was made by HPLC and TLC. The isolation of a β-1 → 4 and a β-1 → 6-rhamnoglucoside of cyclopentenoid cyanogens from three species of subgenus Plectostemma of Passiflora suggests that diglycosides of this type are taxonomically diagnostic for the section.     

Passicoccin: a sulphated cyanogenic glycoside from Passiflora coccinea

A novel cyclopentenoid cyanogenic glycoside (1-(6-O-β-D-rhamnopyranosyl-β-D-glucopyranosyloxy)-cyclopent-2-en-1-nitrile-4-sulphate) has been isolated from Passiflora coccinea. The structure was determined by means of the ¹H and ¹³C NMR spectrum of the sulphate and its corresponding acetate derivative. Identification of the sugar constituents was made by HPLC and TLC. Passicoccin is so far unique to subgenus Distephana and its presence here is evidence for a phylogenetic relationship between Distephana and subgenera Granadilla and Tacsonia.     

Cyanogenic Glycosides from Four Latin American Species of Acacia

The cyanogenic glucosides of four Latin American species of Acacia (Fabceae: Mimosoideae) have been isolated and characterized. Acacia atramentaria (Argentina) contains proacacipetalin, A.aroma (Argentina) linamarin and lotaustralin, A. tortuosa (Venezuela) proacacipetalin and a second presently uncharacterized glycoside, and A. globulifera (Guatemala) epiproacacipetalin which has not previously been reported as naturally occurring.     

Co-occurrence of Valine/Isoleucine-derived and cyclopentenoid cyanogens in a Passiflora species

The valine/isoleucine-derived cyanogenic glycosides linamarin and lotaustralin have been isolated together with the cyclopentenoid cyanogen passibiflorin from Passiflora lutea. This is only the second report of the production of cyanogenic glycosides from more than one biosynthetic pathway in individuals of a single species.     

Steroidal saponins of Asparagus curillus

Three spirostanol and two furostanol glycosides were isolated from a methanol extract of the roots of Asparagus curillus and characterized as 3-O-[α-l-arabinopyranosyl (1→4)- β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-[{α-l-rhamnopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-(25S)-5β-spirostan- 3β-ol, 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β- d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]- 22α-methoxy-(25S)-5β-furostan-3β, 26-diol and 3-O-[{β-d-glucopyranosyl (1→2)} {α-l-arabinopyranosyl (1→4)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]- (25S)-5β-furostan-3β, 22α, 26-triol respectively.     

Oligofurostanosides from Solanum nigrum

One spirostanol glycoside and two furostanol glycosides have been isolated from a methanol extract of the stems and roots of Solanum nigrum and ide     

Flavonoid glycosides of Tribulus pentandrus and T. Terrestris

Twenty-five flavonoid glycosides were detected in Tribulus pentandrus and T. terrestris. The glycosides belong to the common flavonols, kaempferol, quercetin and isorhamnetin, with the 3-gentiobiosides as the major glycosides. Traces of a flavone (tricin) glycoside was also present in T. pentandrus. The separation of Tribulaceae as a distinct family from Zygophyllaceae is discussed.     

Xanthones,flavones and secoiridoids of american Gentiana species

Isoorientin, isoorientin-4′-O-glucoside, gentiopicrin, xanthones with 1,3,5,8 or 1,3,7,8-oxidation pattern have been isolated from five North American Gentiana species (G. affinis, G. algida, G. calycosa, G. detonsa, G. strictiflora) and one South American species (G. cerastioides). Separations were achieved with droplet counter-current chromatography (DCCC) or centrifugally accelerated preparative TLC. The distribution of the isolated compounds within the genus is discussed.     

The flavonoids of phragmites australis flowers

The major flavonoid constituents of Phragmites australis flowers are the C-glycosylflavones swertiajaponin, isoswertiajaponin and two new O-glycosides, the 3′-O-gentiobioside and the 3′-O-glucoside of swertiajaponin. Two unusual flavonol glycosides, rhamnetin 3-O-rutinoside and rhamnetin 3-O-glucoside, were also characterized from the same tissue.     

Acacipetalin from six species of Acacia of Mexico and Texas

Acacipetalin is the principal cyanogenic glycoside in Acacia chiapensis, A. cochliacantha, A. hindsii, A. macracantha, A. schaffneri var. schaffneri (all from Mexico) and A. schaffneri var. bravoensis (Texas).     

Triglochinin in Araceen

Five species of four subfamilies of the Araceae contain triglochinin as the only cyanogenic glucoside. The compound was identified by TLC, PC, IR, NMR and hydrolysis with a triglochinin-specific β-glucosidase.     

Detection and identification of cyanogenic glucosides in six species of Acacia

The presence of prunasin in Acacia deanei ssp. paucijuga, sambunigrin in Acacia cunninghamii, and acacipetalin in Acacia giraffae has been established by both chromatographic and NMR spectral evidence. Mandelonitrile glucosides of unknown configuration in Acacia parramattensis and Acacia pulchella and (an) as yet unidentified glycoside(s) in Acacia farnesiana are also reported.     

Spirostanol glycosides from Asparagus plumosus

Three spirostanol glycosides were isolated from a methanol extract of the leaves of Asparagus plumosus and characterized.     

Cyanogenic glycosides of the Turneraceae

Eighty species of Turneraceae were tested and found to be cyanogenic. Analysis by HPLC and NMR and comparisons of R_t values from paper chromatograms showed all to possess tetraphyllin A and B and epitetraphyllin B and deidaclin as their cyanogens. These data confirm the close relationship of this family with other families which produce structurally related cyanogens: the Passifloraceae, Malesherbiaceae and Flacourtiaceae.     

Tetraphyllin B and epitetraphyillin B sulphates: Novel cyanogenic glucosides from Passiflora caerulea and P. alato-caerulea

An epimeric mixture of tetraphyllin B-4-sulphate and epitetraphyllin B-4-sulphate was isolated from Passiflora caerulea and P. alato-caerulea.     

Tetraphyllin B from Adenia digitata

Tetraphyllin B has been isolated in good yield from the South African plant Adenia digitata. Its structure was established by ¹H and ¹³C NMR.