Light‐Induced Retinal Degeneration Is Prevented by Zinc,a Component in the Age‐related Eye Disease Study Formulation†

Mineral supplements are often included in multivitamin preparations because of their beneficial effects on metabolism. In this study, we used an animal model of light‐induced retinal degeneration to test for photoreceptor cell protection by the essential trace element zinc. Rats were treated with various doses of zinc oxide and then exposed to intense visible light for as long as 8 h. Zinc treatment effectively prevented retinal light damage as determined by rhodopsin and retinal DNA recovery, histology and electrophoretic analysis of DNA damage and oxidized retinal proteins. Zinc oxide was particularly effective when given before light exposure and at doses two‐ to four‐fold higher than recommended by the age‐related eye disease study group. Treated rats exhibited higher serum and retinal pigment epithelial zinc levels and an altered retinal gene expression profile. Using an Ingenuity database, 512 genes with known functional annotations were found to be responsive to zinc supplementation, with 45% of these falling into a network related to cellular growth, proliferation, cell cycle and death. Although these data suggest an integrated and extensive regulatory response, zinc induced changes in gene expression also appear to enhance antioxidative capacity in retina and reduce oxidative damage arising from intense light exposure.     

l-Asparaginase as Potent Anti-leukemic Agent and Its Significance of Having Reduced Glutaminase Side Activity for Better treatment of Acute Lymphoblastic Leukaemia

Acute lymphoblastic leukaemia (ALL) is one of the leading types of malignant disorder seen in children. Viral infections, genetic factors and exposure to chemical carcinogens are some of the factors responsible for causing ALL. Treatment strategies followed for curing ALL include chemotherapy or radiation therapy, wherein, chemotherapy involves the use of the enzymatic drug l-Asparaginase. The enzyme can be produced from various plants, animals, bacterial and fungal sources but, among them, bacterial sources are widely used for production of this enzyme. The enzyme is non-human in origin having certain bottle necks with l-Asparaginase therapy in the form of side effects such as pancreatitis, thrombosis which are mainly due to glutaminase side activity. Hence, present-day research is mainly focussed on minimizing or completely eliminating the glutaminase activity of the enzyme l-Asparaginase. This review is focussed on the complications associated with glutaminase side activity and use of glutaminase free enzymatic drug l-Asparaginase in treating ALL and the other developments related to the modification of the drug for quality treatment.     

Polyoxyethylene cholesteryl ether-based aqueous wormlike micelles

Formation of wormlike micelles (WLMs) in an aqueous mixture of polyoxyethylene cholesteryl ether (ChEO_n; where n = 20 and 30) and polyoxyethylene dodecyl ether (C₁₂EO_m; where m = 3 and 4) has been reported; rheological and small angle X-ray scattering (SAXS) measurements have been performed in the micellar solutions of ChEO_n as a function of C₁₂EO_m for the structural elucidation. When lipophilic cosurfactant, C₁₂EO_m is added to the micellar solutions of ChEO_n, it favors the sphere-to-cylinder transition due to the penetration of C₁₂EO_m in the palisade layer of ChEO_n micelle accompanying an increase in viscosity. When the concentration of C₁₂EO_m is increased, entangled network of WLMs is formed. A strong shear thinning has been observed in highly viscous samples indicating the presence of transient networks. Such samples exhibited viscoelastic behavior and could be described by the Maxwell model with a single stress relaxation mode. A maximum is observed in zero-shear viscosity-C₁₂EO_m plot. With further addition of C₁₂EO_m, viscosity declines and ultimately a phase separation occurs with the formation of turbid solution of vesicular dispersion. This decline has been interpreted in terms of micellar branching induced by an increase in endcap energy, E _c (which is compensated by the formation of branch points, having a mean curvature opposite to that of endcaps). The C₁₂EO_m induced one-dimensional micellar growth has been confirmed by SAXS.     

Photocatalytic cleavage of hydroxytriazenes: a solid-state synthesis of azo-dyes under sunlight irradiation

Sunlight-induced decomposition of hydroxytriazenes, and green photochemical synthesis of azo-dyes is described. Three substituted hydroxytriazenes, viz: 3-hydroxy-3-(2-methylphenyl)-1-(3-chloro-4-fluorophenyl)triazene (o-CFHT), 3-hydroxy-3-(3-methylphenyl)-1-(3-chloro-4-fluorophenyl)triazene (m-CFHT), and 3-hydroxy-3-(4-methylphenyl)-1-(3-chloro-4-fluorophenyl)triazene (p-CFHT) were co-crystallized with ??-naphthol in equimolar ratio and exposed to sunlight for 9?C10?h. The reaction resulted in formation of azo-dyes which were identified by comparison with the products obtained by the conventional method (standard azo-dye), by use of HPLC. A probable mechanism has been suggested. This is first eco-friendly synthesis of azo-dyes using hydroxytriazenes.     

A dimethylsulfonium methylide mediated highly regioselective olefination of conjugated polyolefin 1,1-dioates to conjugated polyene-2-yl-malonates and their applications in Diels-Alder reactions

The reactions between dimethylsulfonium methylide and 1,3-diene- or 1,3,5-triene-1,1-dioates under specific conditions enable the highly regioselective tandem ylide addition-eliminative olefination to provide 1,3-butadien-2-yl- or 1,3,5-hexatriene-2-yl-malonates. Alkylation at malonate methine carbon of 1,3-butadien-2-ylmalonates with a suitable alkyl halide having in-built functionalities for a dienophile generation led to quick assembly of precursors for type 2 intramolecular Diels-Alder reaction. Syntheses of functionalized bicyclo[n.3.1] alkenes (n=5 or 6) with the double bond at the bridgehead position have been achieved via the IMDA. An asymmetric version of this reaction has been developed using a MacMillan's imidazolidinone catalyst, which provided a bicyclo[5.3.1] alkene with very high enantioselectivity. In situ methylation at malonate methine carbon of 1,3,5-hexatriene-2-yl-malonates followed by intermolecular Diels-Alder reaction with N-methylmaleimide provided the cycloadduct with complete regiocontrol and high diastereoselectivity.     

Mammary gland tumor promotion in F1 generation offspring from male and female rats exposed to soy isoflavones for a lifetime

The effect of dietary isoflavones in the form of NOVASOY (NS) was investigated on methylnitrosourea-initiated mammary gland cancer in F1 generation female Sprague Dawley rats from parents who had undergone lifetime exposure to variable levels of dietary NS. In comparison to NS-free dietary groups, lifetime exposure of F1 rats to 40 and 1000 mg/kg diets of NS reduced tumor latency, but did not significantly affect tumor incidence, tumor size, or tumor multiplicity. A significantly lower tumor multiplicity was, however, observed in rats fed the soy-based, NS-free diet compared to the casein-based, NS-free diet. An evaluation of a dose-response relationship pointed towards a biphasic effect, with a trend showing lower tumor incidence, lower tumor multiplicity, and lower tumor size in rats fed 1000 mg/kg diet NS compared to 40 mg/kg diet NS; however, the data failed to achieve statistical significance. Histologically, tumor type significantly differed according to the administered basal diet variety and NS dose. Our data and that of others provide conflicting evidence for chemopreventive effects of soy isoflavones on mammary gland tumor induction. We suggest standardization of interlaboratory experimental approaches for establishing low dose-response relationships for soy and its isoflavones to aid in risk assessment.     

An improved pollen collection and cryopreservation method for highly recalcitrant tropical fruit species of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.)

An improved method for pollen collection from freshly dehiscing anthers of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.) using the organic solvent cyclohexane has been devised. Using this method pollen quantity sufficient for large scale pollinations could be collected and stored for future use. Transport of pollen in viable conditions over long distances, from site of collection (field genebank) to cryolab was successfully devised for both these fruit species. Cryopreservation was successfully applied to achieve long-term pollen storage over periods of up to four years. Pollen viability was tested using in vitro germination, the fluorochromatic reaction (FCR) method and by fruit set following field pollination. On retesting, four year cryostored pollen of different mango and litchi varieties showed high percentage viability as good as fresh control pollens. Pollens of more than 180 cultivars of mango and 19 cultivars of litchi have been stored in the cryogenebank using the technology developed, thus facilitating breeding programmes over the long-term.     

Scaling factors for the prediction of vibrational spectra. II. The aniline molecule and several derivatives

The structure of aniline was studied by semiempirical, ab initio, and density functional methods. Complete geometry optimization of the minimum energy structure and of the transition states for internal rotation and inversion of the amino group was carried out using several levels. The performance of the different methods in calculating and describing the vibrational frequencies of aniline was determined. The normal modes were characterized by the magnitudes and direction of the displacement vectors. Three procedures were used to obtain the scaled frequencies, two of them new, using specific scale factors and scaling equations from the benzene molecule. The errors obtained were compared with those calculated through other standard procedures. A reassignment of several bands was made. A comparison of the cost‐effective method and procedure of scaling was carried out. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005