The lectin nature of α-galactosidases from Vicia faba seeds

α-Galactosidase from Vicia faba seeds has been resolved into three molecular forms, I, II¹ and II², respectively. Enzyme I is a tetramer (M_r 160 000) consisting of identical sub-units (M_r 44000 ± 2000). All three forms display lectin activity with glucose/mannose specificity. Enzyme I has been further studied with respect to its lectin specificity and various factors affecting this property. The results indicate that the catalytic and the lectin sites reside in the same protein molecule. The results presented are unique in that the enzyme activity is specific for galactose and its lectin activity is specific for glucose/mannose.     

Biosynthesis of 1α,2α,3β-trihydroxy-p-menthane by Fusicoccum amygdali

Measurement of isotope ratios in 1α,2α,3β-trihydroxy-p-menthane, which has been biosynthesized in Fusicoccum amygdali from ³H- and ¹⁴C-labelled mevalonate and in its degradation product diosphenol indicates that: (a) four tritium atoms arising from [5-³H₂, 2-¹⁴C]MVA are retained, one more than suggested from the hydroxylation pattern, (b) menth-2-ene-1-ol is generated from an α-terpinyl cation through a 1,3-hydride shift and (c) trans-cleavage of an α-epoxide by hydrolysis gives 1α,2α,3β-trihydroxy-p-menthane.     

The sterol composition of mushrooms

Sterols were isolated from ten mushrooms, Hygrocybe punicea, Lampteromyces japonicus, Leucopaxillus giganteus, Lentinus edodes, Flammulina velutipes, Amanita caesarea, Coprinus atramentarius, Russula foetens, R. nigricans and R. senecis. The compositions of the sterol fractions were determined by GLC, combined GC/MS, and ¹H NMR. Ergosterol was present in all the mushrooms. Other sterols found were 5α-cholest-7-en-3β-ol and ergosta-5,7-dien-3β-ol. Ergosta-5,8,22-trien-3β-ol was isolated from F. velutipes.     

A comparison of lipid components of the fresh and dead leaves and pneumatophores of the mangrove Avicennia marina

The component hydrocarbons, sterols, alcohols, monobasic, α,ω-dibasic and ω-hydroxy acids of the fresh hand decayed leaves and the pneumatophores of the mangrove Avicennia marina are reported in detail. From the quantitative comparisons which can be drawn, relative changes in the lipid classes occurring during leaf decay can be highlighted. These base-line data are important to our understanding of inputs to marine intertidal sediments. During leaf decay the only significant changes were a reduction in the total absolute concentrations of monobasic acids due largely to a decrease in concentration of the C₁₈ polyunsaturated fatty acids, and an enhancement of the concentrations of the long-chain monobasic acids, ω-hydroxy acids and α,ω-dibasic acids. This resistance to degradation shown by the cutin derived acids (α,ω-dibasic, ω-hydroxy and long-chain monobasic acids) relative to the cellular and wax derived lipids may allow these cutin components to be used as quantitative markers of A. marina in mangrove associated sediments.     

24β-Ethyl-31-norlanosta-8,25(27)-dien-3β-ol and 24β-ethyl-25(27)-dehydrolophenol in seeds of three cucurbitaceae species

The structures of two 4α-methylsterols is isolated from Cucumis sativus(Cucurbitaceae) seeds were determined based mainly on their ¹³CNMR spectra as 24β-ethyl-31-norlanosta-8,25(27)-dien-3β-ol and 24β-ethyl-25(27)- dehydrolophenol, respectively, of which the former is a new sterol from natural sources. These two 4α-methylsterols were identified in the seeds of two other Cucurbitaceae species, Lagenaria leucantha var. Gourda and Citrullus battich. The probable biogenetic significance of the two 4α-methylsterols is discussed. Other 4α-methylsterols identified in the seeds of the three Cucurbitaceae species were obtusifoliol, cycloeucalenol and gramisterol.     

Stabilization of rat liver lysosomes by new anti-inflammatory steroids in vitro

Steroid acid esters, synthesized by modifying the 17-ketol side chain of prednisolone, were tested for their in vitro ability to stabilize heavy mitochondrial lysosomes prepared from rat liver. Membrane stabilization was determined by assessing capability of steroids to decrease extrusion of the marker enzymes (acid phosphatase, beta-glucuronidase and aryl sulfatase) from lysosomes incubated in hypo-osmotic sucrose-Tris acetate buffer. Results indicated that prednisolone (1) significantly inhibited the lysosomal release of acid phosphatase as did the new anti-inflammatory steroid, methyl 20-dihydroprednisolonate. Methyl prednisolonate exhibited weak membrane stabilization capacities and 20-dihydroprednisolonic acid, a metabolic product of methyl 20-dihydroprednisolonate, showed virtually no membrane stabilization.     

Androgen metabolism in male and female breast tissue

Incubation studies have been carried out using normal breast tissue and breast tissue from patients with gynecomastia, mammary dysplasia and breast carcinoma to determine the pattern of androstenedione metabolism. All tissues formed estrone (E₁) and testosterone (T) in all incubations. Estradiol (E₂) was isolated in incubations of tissue from 1 to 6 patients with mammary dysplasia, 5 of 6 patients with gynecomastia and in all incubations with normal and carcinoma tissue. Estrone formation was lowest in mammary dysplasia and gynecomastia, and higher in apparently normal breast tissue. The greatest E₁ formation was found in incubations with breast carcinoma tissue, although there was considerable variation within this tissue group. Estradiol formation was low in all tissues, with the highest conversion rates in carcinoma tissue. Testosterone formation in carcinoma tissue was greater than in mammary dysplasia or gynecomastia, but similar to apparently normal tissue. These results indicate that breast tissue from different pathological states varies in its capacity to aromatize androstenedione (A) to estrogenic products and to convert it to other androgens. They have also shown that the pattern of metabolism is distinctive for the nature of the pathological abnormality.     

Terpenes from pittosporaceae

The monoterpenes of the fruits of Pittosporum resiniferum and P. undulatum have been identified. The essential oil of P. resiniferum contai     

Sesquiterpene lactones of Podanthus mitiqui

Ovatifolin and two new sesquiterpene lactones, deacetylovatifolin and arturin (1β-hydroxy-8β-angeloyloxy-eudesmane-4(15),11(13)-diene-6α,12-olide, have been isolated from stems and leaves of Podanthus mitiqui. Two of these compounds showed cytotoxic activity.