Homogeneous phase synthesis of cellulose carbamate silica hybrid materials using 1-n-butyl-3-methylimidazolium chloride ionic liquid medium

Cellulose carbamate silica hybrid materials can be prepared in 78–84% yield using the homogeneous phase reaction of 3-(triethoxysilyl)propyl isocyanate with cellulose dissolved in 1-n-butyl-3-methylimidazolium chloride ionic liquid and then using NH₄OH catalyzed hydrolysis of triethoxysilyl groups and the sol–gel process. New cellulose carbamate silica hybrid materials produced were characterized by elemental analysis, FT-IR, and TG-DTA. The hydrophilic affinity of these materials is shown to decrease with the degree of substitution of the cellulose hydroxyl groups with carbamate groups.     

Superoxide radical production and performance index of Photosystem II in leaves from magnetoprimed soybean seeds

Priming of soybean seeds with static magnetic field exposure of 200 mT (1 h) and 150 mT (1 h) resulted in plants with enhanced performance index (PI). The three components of PI i.e the density of reaction centers in the chlorophyll bed (RC/ABS), exciton trapped per photon absorbed (φpo) and efficiency with which a trapped exciton can move in electron transport chain (Ψo) were found to be 17%, 27%  and 16% higher, respectively in leaves from 200 mT (1h) treated compared to untreated seeds.  EPR spectrum of  O₂^{. –} - PBN  adduct revealed that the O₂^{. –} radical level was lower by 16% in the leaves of plants that emerged from magnetic field treatment. Our study revealed that magnetoprimed seeds have a long lasting stimulatory effect on plants as reduced superoxide production and higher performance index contributed to higher efficiency of light harvesting that consequently increased biomass in plants from treated plants.     

The embryology ofEpipogium roseum (Orchidaceae)

Development of pollen and female gametophyte inEpipogium roseum (D. Don)Lindl. has been investigated. The embryo sac conforms to the Apinagia type. The taxonomic position ofEpipogium within the family is discussed.     

Synthesis of pentafluorophenyl, 2,4,5-trichlorophenyl and pentachlorophenyl esters of Fmoc-amino acids using Fmoc-amino acid chlorides as intermediates

The synthesis of pentafluorophenyl,2,4,5-trichlorophenyl and pentachlorophenyl esters ofFmoc-amino acids has been accomplished via Fmoc-amino acidchlorides as intermediates. A two phase system with a mildin-organic base (3% NaHCO₃) in the aqueous layer was used. The esterification reaction was clean and complete in about2–3 hr. All the esters prepared have been obtained in goodyield and are fully characterised.     

Convenient and efficient synthesis of Boc-/Z-/Fmoc-beta-amino acids employing N-protected alpha-amino acid fluorides.

A new and efficient method for the synthesis of N(alpha)-Fmoc-/Boc-/Z-beta-amino acids using the two-step Arndt-Eistert approach is described. Fmoc-/Boc-/Z-alpha-Amino acid fluorides were used for the acylation of diazomethane synthesizing Fmoc-/Boc-/Z-alpha-aminodiazoketones as crystalline solids with good yield and purity. They were then converted to the corresponding beta-amino acids using PhCOOAg/dioxane/H2O.     

Zinc and immunity

Nutritional deficiency of zinc is widespread throughout the developing countries and a conditioned deficiency of zinc is known to occur in many diseased states. Zinc is known to play an important role in the immune system and zinc deficient subjects may experience increased susceptibility to a variety of pathogens. We have studied the effects of a mild deficiency of zinc on T cells in an experimental model of human zinc deficiency. We showed that T cell functions were affected adversely even when the deficiency of zinc was mild in humans. Characteristically during zinc deficiency, the serum thymulin activity (a thymic hormone) was decreased which was restored following zinc supplementation. Our studies also showed that zinc deficiency caused an imbalance between TH1 and TH2 functions. The production of IFN-g, IL-2, TNF-a (products of TH1 cells) were decreased, whereas the production of IL-4, IL-6 and IL-10 (products of TH2) were not affected during zinc deficiency. T cell subpopulation studies revealed that the CD4+ CD45RA+ to CD4+ CD45RO+ ratio was decreased as a result of zinc deficiency, suggesting that zinc may be required for the regeneration of new CD4+ T cells. We further documented that zinc deficiency decreased NK cell lytic activity and caused a decrease in the percentage of CD8+ CD73+ T cells which are known to be predominantly precursors of cytotoxic T cells. In a suitable cell culture model our studies revealed that the gene expression of a DNA synthesizing enzyme TK was affected adversely which resulted in delayed cell cycle and decreased cell growth. The above immunological consequences of zinc deficiency may be responsible for decreased cell mediated immune functions in zinc deficient subjects.     

Betacyanin biosynthesis in the isolated hypocotyls bei Acetabularia mediterranea

Summary Isolated hypocotyls synthesize betacyanin after light exposure in Amaranthus caudatus L. Pigment synthesizing capacity is reduced in the hypocotyls with increased incubation of seedlings in dark after 24h. External feeding of precursors of betacyanin L-tyrosine and DOPA enhances pigment synthesis in the isolated hypocotyls to equal that of intact hypocotyls. Cotyledons are probably the source of precursors while both cotyledons and hypocotyls are the sites of betacyanin synthesis. Betacyanin synthesizing capacity is progressively lost from the base of the hypocotyl and precursors could not induce pigment synthesis in these regions.     

Engineering of bacterial strains and their products for cancer therapy

The use of live bacteria in cancer therapies offers exciting possibilities. Nowadays, an increasing number of genetically engineered bacteria are emerging in the field, with applications both in therapy and diagnosis. In parallel, purified bacterial products are also gaining relevance as new classes of bioactive products to treat and prevent cancer growth and metastasis. In the first part of the article, we review the latest findings regarding the use of live bacteria and products as anti-cancer agents, paying special attention to immunotoxins, proteins, and peptides. In particular, we focus on the recent results of using azurin or its derived peptide as anticancer therapeutic agents. In the second part, we discuss the challenges of using metagenomic techniques as a distinctive approach for discovering new anti-cancer agents from bacterial origin.