Flavonols and coumarins from the fruit of Murraya omphalocarpa

Separation of the ethanolic extract of the fruit of Murraya omphalocarpa afforded a new flavonol, murrayanol, which was characterized as 5,4′-dihydroxy-3,6,7,3′,5′-pentamethoxyflavone, together with the known substances coumurrayin, mexoticin, 3,5,6,7,3′,4′,5′-heptamethoxyflavone, 5,7-dimethoxy-8-(3′-methyl-2′-oxobutyl) coumarin and sitosterol.     

Isopongaglabol and 6-methoxyisopongaglabol,two new hydroxyfuranoflavones from Pongamia glabra

Isopongaglabol and 6-methoxyisopongaglabol, two new hydroxyfuranoflavones, together with two furanoflavones 5-methoxyfurano(8,7-4″,5″)flavone and 5-methoxy-3′,4′-methylenedioxyfurano(8,7-4″,5″)flavone, two simple flavones, desmethoxykanugin and fisetin tetramethyl ether, a chromenoflavanone, ovalichromene B, two triterpenes, cycloart-23-ene-3β,25-diol and friedelin, and β-sitosterol-β-d-glucoside were isolated from the petrol and CHCl₃ extracts of the flowers of Pongamia glabra. The structures of isopongaglabol and 6-methoxyisopongaglabol have been established as 4′-hydroxyfurano(8,7-4″,5″)flavone and 4′-hydroxy-6-methoxyfurano(8,7-4″,5″)flavone, respectively, on the basis of the spectral evidence and they have been confirmed by synthesis.     

The structure and synthesis of neobavachalcone,a new component of Psoralea corylifolia.

Reinvestigation of the seeds of P. corylifolia has given, besides known compounds, a new formylated chalcone named neobavachalcone whose structure has been deduced as 5′-formyl-2′,4-dihydroxy-4′-methoxychalcone from spectral data and confirmed by synthesis. Its dimethyl ether has also been synthesised by an alternative procedure.     

Flavonoids from the exudate of Acacia neovernicosa

2′,4′-Dihydroxychalcone, 4′-hydroxy-2′-methoxychalcone and 2′,4′-dihydroxy-3′-methoxychalcone were isolated and characterized from the resinous exudate produced by Acacia neovernicosa. Smaller amounts of isoliquiritigenin, pinocembrin and chrysin were also found and identified by their chromatographic properties and UV spectra. The material of one collection contained galangin, 3-methylkaempferol and 3,3′ -dimethylquercetin.     

Microbiological oxidation of sterols by Coriolus hirstus

Fermentation of cholesterol with a culture of Coriolus hirstus yielded a mixture containing 7-oxo-cholesterol and hydroxylated-cholesterol derivatives. Preparation of a possible precursor of antheridiol, 7-oxofucosterol, by this fungus was also examined.     

Lactones,flavonoids and benzophenones from Garcinia conrauana and Garcinia mannii

Two novel lactones have been isolated from the stem barks of Garcinia conrauana and G. mannii. The major component of the bark of G. conrauana was identified as 3-(3$\text{,}\text{?}$ 3″-dimethylallyl)-conrauanalactone [4-hydroxy-3-(3″, 3″-dimethylallyl)-6-pentadecylpyran- 2-one] by comparison of spectral data of the isolated compound and two methylethers with that obtained for the previously isolated conrauanalactone. A minor component of the bark of G. mannii was tentatively identified as 3-α-hydroxy-5-(heptadec-8′-enyl)-tetrahydro- furan-2-one on the basis of spectral data from the isolated compound and its monoacetate. The distributions of biflavonoids and related compounds and benzophenones in the stem bark, heartwood, seeds and leaves of the two species are reported.     

Three highly oxygenated flavone glucuronides in leaves of Spinacia oleracea

Droplet counter-current chromatographic separation and subsequent TLC demonstrated the existence of at least 14 phenolics in the leaves of Spinacia oleracea. Three have now been isolated and identified, respectively, as the 4′-glucuronides of 5,7,4'-trihydroxy-3,6,3′-trimethoxyflavone (jaceidin), 5,3′,4′-trihydroxy-3-methoxy-6:7-methylene-dioxyflavone and 5,4′-dihydroxy-3,3′-dimethoxy-6:7-methylenedioxyflavone.     

Brickellin,a novel flavone from brickellia veronicaefolia and b. chlorolepis

A new highly oxygenated flavone methyl ether has been isolated from Brickellia veronicaefolia and B. chlorolepis. It has been identified as 5,6′-dihydroxy-6,7,2′,3′,4′-pentamethoxyflavone and given the name brickellin.     

New glycoxanthones and flavanone glycosides of Hoppea dichotoma

The whole plant of Hoppea dichotoma has been shown to contain eleven xanthones, two flavanones and two flavones, as major chemical entities, five of which are new naturally occurring compounds. Additionally, four known triterpenes, gluanone, gluanol, friedelin and friedelin-3β-ol, have been isolated as minor entities. The taxonomic significance of the chemical characters of H. dichotoma, which are closely similar to those of Canscora decussata, is appraised.     

Stereospecific reduction of progesterone by Pisum sativum

[4 -¹⁴C]-Progesterone was applied to the leaves of growing pea plants, Pisum sativum. After 3 weeks, about 50% of the administered steroid was reduced, about 20% being reduced to 5α-pregnane-3α,20β-diol as the major metabolite. The radioactivities of 5α-pregnane-3α,20α-diol and 5α-pregnane-3α,20β-diol after 3 weeks were more than twice those after one week. The following radioactive metabolises were also isolated: 5α-pregnane-3,20-dione; 20α-hydroxy-4- pregnen-3-one; 20β-hydroxy-4-pregnen-3-one; 3α-hydroxy-5α-pregnan-20-one; 3α-hydroxy-5β-pregnan-20-one; 3β-hydroxy- 5α-pregnan-20-one; 20β-hydroxy-5α-pregnan-3-one; 5α-pregnane-3β,20β-diol; and 5β-pregnane-3α,20β-diol. The radioactivities of the 5α-pregnane derivatives were considerably higher than those of the corresponding 5β-pregnane derivatives.     

Novel 2′-substituted flavonols from the farinose exudate of Notholaena affinis

The farinose exudate produced on the undersurface of fronds of Notholaena affinis consists of a variety of lipophilic flavonol aglycones. Four of these have been identified as novel interrelated compounds. They all bear methoxyl groups in positions 3,6,7,8 and hydroxyl and/or methoxyl groups at 2′,4′.     

Alkaloids,coumarins, triterpenes and a flavanone from the root of Zanthoxylum dipetalum

The root bark of Zanthoxylum dipetalum contained the alkaloids canthin-6-one, chelerythrine, nitidine and tembetarine, the pyranocoumarins avicennol and xanthoxyletin, the triterpene lupeol and the flavanoid hesperidin. The MS fragmentation pattern for avicennol is discussed and a tentative structure is proposed for a third coumarin, designated ZD/1. The root wood of the type species and the stem bark of the γ variety contained most of the above compounds plus sitosterol and, in the root wood only, magnoflorine. The chemotaxonomic implications of these findings are briefly discussed.     

The influence of uncouplers on facilitated diffusion of sorbose in Saccharomyces cerevisiae

Sorbose uptake in Saccharomyces cerevisiae, strain Delft 1, proceeds via mediated passive transport. In the cell sorbose is distributed in at least two compartments. Efflux studies showed that sorbose uptake in one of these compartments is not readily reversible. Uncouplers of oxidative phosphorylation inhibit both transport velocity and steady-state uptake level. It could be shown that these two effects are caused by different modes of action of the uncouplers. None of these two effects could be ascribed to changes of the electrochemical H⁺ gradient or of the intracellular pH. It is suggested that the inhibition of uptake velocity is caused by binding of the uncoupler to the sorbose translocator, thus lowering the transport activity. The uncoupler binding site is probably located at the intracellular fragment of the carrier. The second effect, reduction of the steady-state uptake level, is probably due to blocking of sorbose influx into the compartment that exhibits poor reversibility.     

Two new neoflavonoids and C-glycosylflavones from Passiflora serratodigitata

The aerial parts of Passiflora serratodigitata yielded 5,7-dihydroxy-4-phenylcoumarin, its 7-β-glucoside and the known C-glycosylflavones 2″-xylosylvitexin, 2″-xylosylisovitexin, vitexin, isovitexin, a vicenin, and orientin. The known flavone chrysin was also isolated. This is the first report of neoflavonoids in the family Passifloraceae.