Okanin 4′-O-diglucoside from Coreopsis petrophiloides and comments on anthochlors and evolution in Coreopsis

A new chalcone glycoside, okanin 4′-O-diglucoside, is identified from the ray florets of Coreopsis petrophiloides. The known distribution of anthochlors in Coreopsis indicates that two of the most primitive sections produce in their floral parts complex glucosides of butein (and sulfuretin). The more advanced sections synthesize the monoglucosides of okanin (marein), butein (coreospin) and lanceoletin (lanceolin) and their corresponding aurones. The co-occurrence of marein and lanceolin is thus far restricted to members of sect. Coreopsis.     

Structure of indole-3-acetic acid myoinositol esters and pentamethyl-myoinositols

GC-MS properties of three isomeric esters of indole-3-acetic acid and myoinositol, three esters of indole-3-acectic acid and myoinositol arabinoside and three esters of indole-3-acetic acid and myoinositol galactoside are presented. MS fragmentation patterns for the four possible pentamethyl myoinositols are also shown. These data indicated that the arabinose, and galactose of the glycosides were in the pyranose form and that C-1 of the sugar was linked to the 5 hydroxyl of myoinositol. Homologies in fragmentation patterns for the esters and the glycoside esters, together with knowledge of the properties of 2-O-indole-3-acetyl-myoinositol, permitted identification of one of the arabinosides as 5-O-l-arabinopyranosyl-2-O-indole-3-acetyl-myoinositol and one of the galactosides as 5-O-d- galactopyranosyl-2-O-indole-3-acetyl-myoinositol. The remaining two GLC peaks observed for the arabinoside were then, most likely, the two mixtures of diastereoisomers 1 d- and 1 l-5-O-l-arabinopryranosyl-1-O-indole-3-acetyl myoinositol and 1 d- and 1 l-5-O-l-arabinopyranosyl-4-O-indole-3-acetyl-myoinositol. The remaining two GLC peaks observed for the galactoside would then be the 1 d and 1 l-5-O-d-galactopyranosyl-1-O-indole-3-acetyl-myoinositol and 1 d- and 1 l-5-O-d- galactopyranosyl-4-O-indoleacetyl-myoinositol.     

Hydrolysable tannins and proanthocyanidins from green tea

Two hydrolysable tannins were isolated from green tea, and their structures were characterized by chemical and spectral means as 1,4,6-tri-O -galloyl-β-d-glucose and 1-O-galloyl-4,6-(?)-hexahydroxydiphenoyl-β-d-glucose. In addition, a new proanthocyanidin gallate was isolated, together with the known procyanidins B-2, B-4 and C-1. The structure of the proanthocyanidin was established as epigallocatechin-(4β → 8)-3-O-galloylepicatechin.     

Flavonoide aus salix alba. Die struktur des Terniflorins und eines weiteren acylflavonoides

Eight flavonoids were isolated from the leaves of Salix alba. One, apigenin 7-O-(4-p-coumarylglucoside), is a new natural compound; another, terniflorin, the 6-isomer, is an artefact. The others are quercetin 3-O-glucoside, quercetin 3-O-rutinoside, isorhamnetin 3-O-glucoside, isorhamnetin 3-O-rutinoside and quercetin 7,′3-dimethylether 3-O-glucoside.     

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.     

Flavonoid glycosides from the leaves of Aphananthe aspera (Thunb.) Planch. (Cannabaceae) and their chemotaxonomic significance

From the leaves of Aphananthe aspera (Thunb.) Planch. (Family: Cannabaceae), six flavonol glycosides, such as quercetin 3-O-β-glucopyranoside (1), kaempferol 3-O-β-glucopyranoside (2), quercetin 3-O-rutinoside (3), kaempferol 3-O-rutinoside (4), quercetin 3-O-neohesperidoside (5) and kaempferol 3-O-neohesperidoside (6) were isolated and identified. Structure elucidation of these compounds was performed on the basis of NMR spectral data. All these compounds were isolated for the first time from the genus Aphananthe. Chemotaxonomic significance and distribution of these flavonoid derivatives among the genera of Cannabaceae are explained in detail.     

Aurones interfere with Leishmania major mitochondrial fumarate reductase

A series of aurones was analyzed for the ability to inhibit respiratory functions of mitochondria of Leishmania parasites. The aim of this study was to find a rational explanation for the activity of certain aurones and auronols as novel antiprotozoal compounds of plant origin. In a cell-free assay mitochondrial fumarate reductase from L. donovani was inhibited in a concentration-dependent manner. The most active compounds were 4',6-dihydroxyaurone and 6-methoxyaurone which inhibited parasite enzyme activity at 25 nM by over ninety percent.     

Flavonoid variation in the liverwort Conocephalum conicum: Evidence for geographic races

The flavonoids of 2 samples of Conocephalum conicum gametophyte tissue have been studied, one from U.S.A. and the other from Germany. Common to both samples were vicenin-2, lucenin-2, the 7-O-glucuronides of apigenin, chrysoeriol and luteolin and the previously unknown 7-O-glucuronide 4′-O-rhamnosides of apigenin, chrysoeriol and luteolin. Additionally the German sample contained the 7,4′-di-O-glucuronides of apigenin and luteolin and a new compound, apigenin 7-O-diglucuronide 4′-O-glucuronide. The North American sample contained, additionally, luteolin 7,3′-di-O-glucuronide, luteolin 7-O-glucuronide 3′,4′-di-O-rhamnoside (a new triglycoside) and 2 further derivatives of luteolin 7-O-glucuronide. Evidence is presented for the existence of geographic faces of C. conicum and for the qualitative invariability of the flavonoid patterns with changing season or environment.     

Quercetin 3-glucosylgalactoside from pollen of Corylus avellana

The main flavonoid glycoside from the pollen of Corylus avellana has been characterized as quercetin 3-O-(2″-O-β-d-glucopyranosyl)-β-d-galactopyranoside on the basis of UV, ¹H NMR, ¹³C NMR and mass spectral data and GLC sugar analysis.     

Unique flavonoid glycosides from the new zealand white pine, Dacrycarpus dacrydioides

A number of new flavonoid glycosides have been isolated from foliage of the New Zealand white pine, Dacrycarpus dacrydioides. These include tricetin 3′,5′-di-O-β-glucopyranoside; the 3′-O-β-xylopyranoside, 7-O-α-rhamnopyranoside and 7-O-α-rhamnopyranoside-3′-O-β-xylopyranoside of 3-O-methylmyricetin; the 3′-O-β-xylopyranoside, 7-O-α-rhamnopyranoside and 7-O-α-rhamnopyranoside-3′-O-β-xylopyranoside of 3-O-methyl-quercetin, and the 3′-O-β-xylopyranoside and 7-O-α-rhamnopyranoside-3′-O-β-xylopyranoside of 3,4′-di-O-methylmyricetin. The accumulation of 3-methoxyflavones and B-ring trioxygenated flavonoids appears to distinguish D. dacrydioides from all other New Zealand members of the classical genus Podocarpus. Support for De Laubenfels' proposed separation of Dacrycarpus from this genus is seen in the present work.     

Two perenniporiol derivatives,lanostane-type triterpenoids,from the cultured mycelia of Perenniporia ochroleuca

Two new perenniporiol derivatives, lanostane-type triterpenoids, were isolated from the benzene extract of cultured mycelia of Perenniporia ochroleuca. The structures of the two new compounds were elucidated by spectral data to be 3-O-acetyl-7,11-dihydroperenniporiol and 12β-acetoxyperenniporiol.     

Phenolic glycerides from Lilium auratum

Phenolic glycerides have been isolated from fresh bulbs of Lilium auratum. By spectral and chemical means, they have been identified as the new components, 1,2-O-diferuloylglycerol, a mixture of 1-O-feruloyl-2-O-p-coumaroylglycerol and 1-O-p-coumaroyl-2-O-feruloylglycerol, 1-O-feruloylglycerol and the known compounds, 1,3-O-diferuloylglycerol, 1-O-feruloyl-3-O-p-coumaroylglycerol and 1-O-p-coumaroylglycerol.     

Synthesis and growth regulator activity of fatty acyl derivatives of d-glucose and d-galactose

In an attempt to gain information about one or more components of the brassin complex, fatty acid esters of d-glucose and d-galactose were prepared and tested for growth regulator activity in a bean hypocotyl bioassay. 4-O-Acyl-d-glucoses and, perhaps, 1-O-acyl- d-galactoses had a similar qualitative activity to that of the brassin complex. 3-O-Acyl- d-galactoses inhibited elongation of bean hypocotyls and stimulated rooting. 3- And 6-O- acyl-d-glucoses both stimulated and inhibited elongation, depending on the source of fatty acids; in both cases, stimulation was observed when safflower oil was used as the source of fatty acids and inhibition was observed when peanut oil was used as the source of fatty acids. Fatty alkyl β-d-galactopyranosides were inactive.     

Flavonoids of the flowers of tamarix nilotica

The ethyl ester of kaempferol 3-O-β-D-glucuronide, the methyl and ethyl esters of quercetin 3-O-β-D-glucuronide have been isolated from an aqueous acetone extract of the flowers of Tamarix nilotica. In addition kaempferol 3-O-sulphate-7,4′-dimethyl ether and the free aglycones were isolated. The structures were established by routine methods, by FAB-MS and by ¹³C NMR spectral measurements.     

Fragmentation pattern of permethyl 6-C-glycosylflavones in electron impact mass spectrometry

A mass spectral fragmentation pattern of permethyl 6-C-glycosylflavones is proposed from the MS data of permethyl derivatives mono-O-deuteriomethylated in the 2″-, 3″-, 4″- or 6″-positions. The synthesis of these compounds via O″-glycosyl-6-C-glucosylflavones is described.     

Five glycosides from the chinese drug ‘tong-guang-san’: The stems of marsdenia tenacissima

Five new glycosides were isolated from the Chinese crude drug ‘Tong-guang-san’: the stems of Marsdenia tenacissima (Roth.) Wight et Arn. (Asclepiadaceae). The structures of tenacissosides A-E were deduced on the basis of chemical and spectral evidence as tenacigenin B-I 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D- allopyranosyl-(1→4)-β-D-oleandropyranoside, tenacigenin B-II 3-O-β-D-glucopyranosyl-(1 →4)-3-O-methyl-6-deoxy- β-Dallopyranosyl-(1 →4)-β-D-oleandropyranoside, tenacigenin B-III 3-O-β-Dglucopyranosyl-(1→4)-3-O-methyl-6- deoxy-β-D-allopyranosyl-(1 → 4)-β-D-oleandropyranoside, tenacigenin B-IV 3-O-β-D-glucopyranosyl-(1 →4)-3-O- methyl-6-deoxy-β-D-allopyranosyl-(1 → 4)-β-D-oleandropyranoside and tenacigenin B-V 3-O-β-D-glucopyranosyl- (1 → 4)-3-O-methyl-6-deoxy-allopyranosyl-(1 → 4)-β-D-oleandropyranoside, respectively.     

Flavonol glycosides from Epimedium sagittatum

Two new flavonol glycosides were isolated from Epimedium sagittatum besides the known flavonol glycosides, icariin and icarisid I. On the basis of spectral analyses, the structures of the compounds were determined to be anhydroicaritin-3-O-α-rhamnoside and icaritin-3-O-α-rhamnoside.     

Two acylated flavanone glycosides from Nierembergia hippomanica

Two new acylated flavanone glycosides have been isolated from Nierembergia hippomanica and identified by spectral data as pinocembrin 7-O-β-(3?-O-acetyl)neohesperidoside and pinocembrin 7-O-β-(6″-O-acetyl)neohesperidoside.     

Synthèse de trithioorthocarbonates de pyranosides par thermolyse de bis(dithiocarbonates)

The thermal decomposition of methyl 4,6-O-benzylidene-2,3-di-O-[(methylthio)-thiocarbonyl]-α-d-glucopyranoside afforded methyl 4,6-O-benzylidene-2-thio-α-d-mannopyranoside 3-O,2-S-(S,S-dimethyl trithioorthocarbonate) and methyl 4,6-O-benzylidene-3-thio-α-d-allopyranoside 2-O,3-S-(S,S-dimethyl trithioorthocarbonate) in good yield. This decomposition can be generalized to 1,3-diols derived from sugars. Thus methyl 2,3-di-O-methyl-4,6-di-O-[(methylthio)thiocarbonyl]-α-d-glucopyranoside afforded in the same way the corresponding trithioorthocarbonates, following a regioselective process. The structures of these trithioorthocarbonates are confirmed by spectral and chemical proofs.     

Flavonoid glycosides from the aerial parts of Curcuma comosa

Four new flavonoid glycosides, curcucomosides A–D (1–4), three known flavonoid glycosides, 5–7, and four known diarylheptanoids, 8–11, were isolated from the ethanol extract of the aerial parts of Curcuma comosa. The structures of the new compounds were established as rhamnazin 3-O-α-l-arabinopyranoside (1), rhamnocitrin 3-O-α-l-arabinopyranoside (2), rhamnazin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (3), and rhamnocitrin 3-O-α-l-rhamnopyranosyl-(1→2)-O-α-l-arabinopyranoside (4) by spectroscopic analysis and chemical reactions whereas those of the known compounds were identified by spectral comparison with those of the reported values.