Habib Nasir

Insects are unable to synthesize sterols and require exogenous sterol sources for their normal development and reproduction. A few exceptions are insects associated with symbiotic yeasts or fungi. We analyzed sterols by GC-MS in two anobiid beetles (Lasioderma serricorne and Stegobium paniceum), their intracellular yeast-like symbiotes (YLS), and their diets in order to clarify the sterols synthesized by YLS and the metabolic pathways of the sterols in the beetles. Several C27, C28, and C29 saturated and unsaturated sterols were identified; the predominant sterols were cholesterol and 7-dehydrocholesterol in the anobiid beetles and ergosterol in the YLS. Most sterols detected in YLS were those known in the late pathway of the ergosterol biosynthesis in yeasts and most of the sterols in the beetles appear to be intermediate metabolites from YLS sterols to 7-dehydrocholesterol. The anobiid beetles appear to use ergosterol and 5-dihydroergosterol as sources for 7-dehydrocholesterol. Arch. Insect Biochem. Physiol. 52:175–182, 2003. © 2003 Wiley-Liss, Inc.

Desizing is one of the key processes for the pretreatment of cotton fabric wet processing. Prior to dyeing and printing, it is essential to remove the sizes coated on fabric. Cleaner production technologies, using which hazardous material is substituted with -amylase, an eco-friendly material, are applied for desizing of cotton fabric. The enzymatic desizing process is human-, machine-, and environmentally-friendly. Four different types of machines were used to investigate the aspects and results of enzymatic desizing. Unlike acid and oxidative desizing, biodegradation of sizes does not damage fabric and emit greenhouse gases (CO2), respectively. The highest quality of desizing was observed by using winch technology. The degree of desizing on TEGEWA scale was 8. The amount of desizing agent used was 0.5–4.0 kg/1000 liters. In winch (batch) desizing, the degree of whiteness was 76%, which is 1.5 times higher than grey fabric, but pad steam (continuous) desizing process showed 69% degree of whiteness, which is 1.35 times higher than grey fabric. The competitive results were achieved in continuous process with efficient time. This article reveals the benefits, processes and results of eco-friendly technology within the framework of textile wet process industry.

A new seco-triterpene, buxapapillosin (1) in which ring A has undergone cleavage, has been isolated from the roots of Buxus papillosa. The compound bears a cyclopropane ring found in many Buxus alkaloids and is therefore of biogenetic significance. The leaves of Buxus papillosa have also yielded three known alkaloids, buxamine A, cyclomicrobuxamine and cyclomicrobuxinine, isolated for the first time from

The fungus Cephalosporium aphidicola has been shown to hydroxylate testosterone, 19-nortestosterone, 1-dehydrotestosterone, 1α-methyltestosterone, androst-4-en-3-one, androst-4-en-3,17-dione and 17α-methyltestosterone predominantly at the C-6β position with a minor hydroxylation occurring at the C-14α position. 19-Nortestosterone was also hydroxylated at the C-10β position. In contrast to the hydroxylation of progesterone by this organism, hydroxylation at C-11α was a minor pathway.

Robinia pseudo-acacia L. (black locust) is a nonindigenous species currently invading the central part of Japanese grasslands. Several allelochemicals were identified and characterized from the leaf tissue. The growth of both radicle and hypocotyl in the tested species (barnyard grass, white clover, lettuce, and Chinese cabbage) was reduced when grown in soil mixed with the leaves of R. pseudo-acacia at various concentrations. Aqueous leaf extracts, when bioassayed, exhibited a significant suppression of radicle growth. Chromatographic separation of an ethanolic extract of R. pseudo-acacia leaves resulted in isolation of three compounds, identified as robinetin (1), myricetin (2), and quercetin (3) by nuclear magnetic resonance and mass spectroscopy. All inhibited root and shoot growth of lettuce. Robinetin, found in a large amount, caused 50% suppression of the root and shoot growth of lettuce at 100 ppm. The presence of these bioactive substances in leaf tissue suggests a potential role for flavonoids in R. pseudo-acacia invasion in introduced habitats.

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Buxus papillosa CK Schneider (Buxaceae) is a shrub widely distributed in the northern regions of Pakistan and locally known as Shamshad (1). Extracts of the shrub find extensive use in the indigenous system of medicine for the treatment ofvarious disorders, especially ...

Lycoris radiata Herb., a common medicinal plant of Far East Asia, was examined for its potential use in paddy weed control. The preliminary screening in greenhouse conditions indicated growth inhibitory activities. The emergence, root and shoot growth, and root dry weight of the bioassay species were reduced when grown in soil mixed with the leaves of L. radiata. Aqueous extracts of the fresh leaves at various concentrations inhibited the root and shoot growth of all tested plant species. To identify the active components, L. radiata ethanolic extract was subjected to bioassay-guided fractionation, purification, and spectroscopic analysis. This process led to the isolation of lycorine as a potential allelochemical. The concentration of lycorine in the dry leaves of L. radiata is estimated to be 0.08%. It is possible that lycorine is exuded from the roots or leaches from the living or decomposing leaves, along with other numerous inhibitors, and inhibits the growth of neighboring or successional plants. These results suggest that L. radiata has the potential to inhibit plant growth and lycorine acts as one of the most important plant growth inhibitors. This plant can be grown as a ground cover plant and its dead leaves could be applied as cover mulch.

... 2, pp. 683-685, 1990, Printed n Great Britain. ... 0031--9422/90 $3.00+0.00 1990 Pergamon Press plc ATTA-UR-RAHMAN,* ZAHIDA IQBAL, MUZAFFAR ALAM, M. IQBAL CHOUDHARY, HABIB NASIR and TALAT FATIMA HEJ Research Institute of Chemistry, University of Karachi ...