Synthesis and Characterisation of Metal Hydrazine Nitrate, Azide and Perchlorate Complexes

Metal hydrazine nitrate complexes of the type M(N2H4)Nn (NO3)2 where M = Mg, n = 2; M = Mn, Fe, Co, Ni, Zn and Cd and n = 3; metal dihydrazine azide complexes of the type M(N2H4)2 (N3)2 where M = Mg, Co, Ni and Zn; and Mg(N2H4)2 (C1O4)2 have been prepared by dissolving the respective metal powders in the solution of corresponding ammonium salts (NO3, N3 and C1O4) in hydrazine hydrate. These hydrazine complexes were also prepared by the conventional method involving the addition of alcoholic hydrazine hydrate to the aqueous solution of metal salts. The hydrazine complexes have been characterised by chemical analysis, infrared spectra and differential thermal analysis (DTA). Impact sensitivities of hydrazine complexes were determined by the drop weight method. The reactivity of these hydrazine complexes does not change with the method of preparation.

Synthesis and Characterisation of Metal Hydrazine Nitrate, Azide and Perchlorate Complexes

Metal hydrazine nitrate complexes of the type M(N2H4)Nn (NO3)2 where M = Mg, n = 2; M = Mn, Fe, Co, Ni, Zn and Cd and n = 3; metal dihydrazine azide complexes of the type M(N2H4)2 (N3)2 where M = Mg, Co, Ni and Zn; and Mg(N2H4)2 (C1O4)2 have been prepared by dissolving the respective metal powders in the solution of corresponding ammonium salts (NO3, N3 and C1O4) in hydrazine hydrate. These hydrazine complexes were also prepared by the conventional method involving the addition of alcoholic hydrazine hydrate to the aqueous solution of metal salts. The hydrazine complexes have been characterised by chemical analysis, infrared spectra and differential thermal analysis (DTA). Impact sensitivities of hydrazine complexes were determined by the drop weight method. The reactivity of these hydrazine complexes does not change with the method of preparation.

Metabolism of a monoterpene alcohol, linalool, by a soil pseudomonad

A microorganism of the genus Pseudomonas has been isolated from the soil by enrichment culture techniques with linalool(I) as the sole source of carbon and energy. The organism is also capable of utilizing limonene, citronellol, and geraniol as substrates but fails to grow on citral, critranellal, and 1,8-cineole. Fermentation of linalool by this bacterium in a mineral salt medium results in the formation of 10-hydroxylinalool(II), oleuropeic acid (IX), 2-vinyl-2-methyl-5-hydroxyisopropyl-tetraphydrofuran)linalool oxide, V), 2-vinyl-2-methyl-tetrahydrofuran-5-one(unsaturated lactone, VI), and few unidentified minor metabolities. Probable pathways for the biodegradation of linalool are presented.

Adsorption-desorption and photocatalytic properties of inorganic-organic hybrid cadmium thiosulfate compounds

Three inorganic-organic hybrid framework cadmium thiosulfate phases have been investigated for adsorption and photodegradation of organic dye molecules. Different classes of organic dyes, viz., triaryl methane, azo, xanthene, anthraquinone, have been studied. The anionic dyes with sulfonate groups appear to readily adsorb on the cadmium thiosulfate compounds in an aqueous medium. The adsorption of the dye molecules, however, does not create any structural changes on the cadmium thiosulfate compounds, though weak electronic interactions have been observed. The adsorbed dyes have been desorbed partially in an alcoholic medium, suggesting possible applications in scavenging specific anionic dyes from the aqueous solutions. Langmuir adsorption/desorption isotherms have been used to model this behavior. UV-assisted (lambda(max) = 365 nm) photocatalytic decomposition studies on the cationic dyes indicate reasonable activity comparable with that of Degussa P-25 (TiO2) catalyst. Sunlight assisted photocatalyti studies have been carried out in detail employing hybrid framework compounds. The Langmuir-Hinshelwood kinetics model, employed to follow the degradation profile of the organic dyes, indicates that the photocatalytic degradation follows the order: triaryl methane > azo > xanthene.

Resource recovery potential from secondary components of segregated municipal solid wastes

Fermentable components of municipal solid wastes (MSW) such as fruit and vegetable wastes (FVW), leaf litter, paddy straw, cane bagasse, cane trash and paper are generated in large quantities at various pockets of the city. These form potential feedstocks for decentralized biogas plants to be operated in the vicinity. We characterized the fermentation potential of six of the above MSW fractions for their suitability to be converted to biogas and anaerobic compost using the solid-state stratified bed (SSB) process in a laboratory study. FVW and leaf litter (papermulberry leaves) decomposed almost completely while paddy straw, sugarcane trash, sugarcane bagasse and photocopying paper decomposed to a lower extent. In the SSB process between 50-60% of the biological methane potential (BMP) could be realized. Observations revealed that the SSB process needs to be adapted differently for each of the feedstocks to obtain a higher gas recovery. Bagasse produced the largest fraction of anaerobic compost (fermentation residue) and has the potential for reuse in many ways.

Stereoselectivity in the addition of hydrogen chloride to cyclohex-1-enecarbonitrile: Possible role of chlorine lone pair-nitrile π-orbital pseudoallylic A1, 3 interaction

The (overall trans) addition of hydrogen chloride to cyclohex-1- enecarbonitrile in anhydrous alcoholic media proceeds to give cis-2-chlorocyclohexanecarboxylate (together with some cis-2- chlorocyclohexanecarboxamide): no corresponding products with the trans-configuration are detectable. In anhydrous ether the addition proceeds to give a single isomer, presumably cis-, of 2-chlorocyclohexanecarbonitrile, indicating that the configuration of the products may not be equilibrium-controlled in alcoholic media. An examination of the steric factors indicates that the transition state for protonation of the presumed intermediate, 2-chlorocyclohexylidenemethylideneimine, leading to cis-product is favoured if interaction between the lateral π-orbital of the C-N double bond and the lone-pairs on the chlorine atom at the 2-position is large. Consideration of interactions in the transition states meets Zimmerman's criticism that invoking A1, 3 interaction existing in ground states to explain product configuration takes insufficient account of the Curtin-Hammett principle.

Jodimetric estimation of water-soluble dithiocarbamates

Iodimetric estimation of dialkyl dithiocarbamate in alcoholic solution is not accurate. The method has not met with success for the water-soluble dithiocarbamates before. A simple and accurate iodimetric method has been developed for the estimation of water-soluble dithiocarbamates. The success of the method is due to the removal of the oxidation product which interferes during the titration with iodine.

Determination of carbon disulphide by chloramine-T

Carbon disulphide, on treatment with alcoholic potash, can readily be oxidised quantitatively by chloramine-T, converting all the sulphur to sulphuric acid. Fourteen equivalents of the oxidant are consumed for every mole of carbon disulphide. Since excess of chloramine-T may be determined iodimetrically, this reaction may be used for the determination of carbon disulphide. It may also be applied to the determination of xanthates.

Purification and properties of β-glucosidase from a thermophilic fungus Humicola lanuginosa (Griffon and Maublanc) Bunce

An extracellular β-glucosidase (EC 3.2.1.21) has been purified to homogeneity from the culture filtrate of a thermophilic fungus, Humicola lanuginosa (Griffon and Maublanc) Bunce, using duplicating paper as the carbon source. The enzyme was purified 82-fold with a 43% yield by ion-exchange chromatography and gel filtration. The molecular weight of the protein was estimated to be 135,000 by gel filtration and 110,000 by electrophoresis. The sedimentation coefficient was 10.5 S. It was an acidic protein containing high amounts of acidic amino acid residues. It was poor in sulphur-containing amino acids. It also contained 9% carbohydrate. The enzyme activity was optimum at pH 4.5 and at 60°C. The enzyme was stable in the pH range 6–9 for 24 h at 25°C. The enzyme had similar affinities towards cellobiose and p-nitrophenyl-β-d-glucoside with Km values of 0.44 mM and 0.50 mM, respectively. The enzyme was capable of hydrolysing larchwood xylan, xylobiose and p-nitrophenyl-β-d-xyloside, though to a lesser extent. The enzyme was specific for the β-configuration and glucose moiety in the substrate.

Purification and characterization of endo-1,4-β-xylanase from Paecilomyces varioti Bainier

An endo-xylanase (1,4-β-d-xylanxylanohydrolase EC 3.2.1.8) was isolated from the culture filtrate of Paecilomyces varioti Bainier. The enzyme was purified 3.2 fold with a 60% yield by gel filtration and ion exchange chromatography. The purified enzyme had a molecular weight of 25,000 with a sedimentation coefficient of 2.2 S. The isoelectric point of the enzyme was 3.9. The enzyme was obtained in crystalline form. The optimum pH range was 5.5–7.0 and the temperature, 65°C. The Michaelis constant was 2.5 mg larchwood xylan/ml. The enzyme was found to degrade xylan by an endo mechanism producing arabinose, xylobiose, xylo- and arabinosylxylo-oligosaccharides, during the initial stages of hydrolysis. On prolonged incubation, xylotriose, arabinosylxylotriose and xylobiose were the major products with traces of xylotetraose, xylose and arabinose.

Spectroscopic, microscopic and first rheological investigations in charge-transfer interaction induced organogels

This article describes two-component charge-transfer interaction mediated organogels (CT-gels) derived from anthracene carboxamides obtained from 2-amino 2-hydroxymethyl-1,3-propanediol (TRIS), and 2,3-dialkoxyanthracenes as donors, with 2,4,7-trinitrofluorenone (TNF) as the common acceptor. We demonstrate the versatility of TNF as an electron acceptor in the formation of these gels. The effect of subtle changes in the donor structure on the gelation ability has been investigated by varying the alkyl chain length in the dialkoxyanthracene donors, and by varying the position of the TRIS substituent in the anthracene carboxamide donors. Distinct differences have been observed in the nature of the CT-gels based on these two kinds of anthracene donors. It has been reported in the literature that 2,3-dialkoxyanthracenes form gels on their own in various aliphatic hydrocarbons and alcohols for linear alkyl chains bearing at least 6mcarbon atoms (C-6). In the present study, it is shown that themCT-complex of these molecules with TNF is able to gel many alcoholic and a few hydrocarbon solvents. Also, in the presence of TNF, the 2,3-dialkoxyanthracenes (C-4-C-5) which were non-gelators on their own at ambient temperatures, form CT-gels in a number of alcohols. The other series of gelators discussed, the anthracene carboxamides, require the mandatory presence of TNF to form gels. This donor-acceptor complex forms gels in various aliphatic alcohols. Interestingly, the formation of these CT-gels requires rapid cooling in most of the cases. Thermal stability studies with both types of CT-gels indicate an optimum stoichiometry of 1 : 1 between the donor and the acceptor. Dynamic rheological experiments reveal these gels as viscoelastic soft materials, with the mechanical strength of these gels depending on the amount of TNF present. This provides a means to tune the strength of the gel by varying the doping concentration of the acceptor.

Studies in biogas technology. Part III. Thermal analysis of biogas plants

A thermal model for a conventional biogas plant has been developed in order to understand the heat transfer from the slurry and the gas holder to the surrounding earth and air respectively. The computations have been performed for two conditions : (i) when the slurry is at an ambient temperature of 20°C, and (ii) when it is at 35°C, the optimum temperature for anaerobic fermentation. Under both these conditions, the gas holder is the major “culprit” with regard to heat losses from the biogas plant. The calculations provide an estimate for the heat which has to be supplied by external means to compensate for the net heat losses which occur if the slurry is to be maintained at 35°C. Even if this external supply of heat is realised through (the calorific value of) biogas, there is a net increase in the biogas output, and therefore a net benefit, by operating the plant at 35°C. At this elevated temperature, the cooling effect of adding the influent at ambient temperature is not insignificant. In conclusion, the results of the thermal analysis are used to define a strategy for operating biogas plants at optimum temperatures, or at higher temperatures than the ambient.

A New Pathway for the Degradation of a Sesquiterpene Alcohol, Nerolidol by Alcaligenes eutrophus

An oxidative pathway hitherto unknown for tile degradation of a sesquiterpene alcohol, nerolidol (I) by Alcaligenes eutrophus is presented. Fermentation of nerolidol (I) by this organism in a mineral salts medium resulted in the formation of geranylacetone (II) and an optically active alcohol (S)-(+)-geranylacetol (III), as major metabolites. Nerolidol (I) induced cells readily transformed 1,2-epoxynerolidol (IV) and 1,2-dihydroxynerolidol (V) into geranylacetone (II). These cells also exhibited their ability to carry out stereospecific reduction of II into (S)-(+)-geranylacetol (III). Oxygen uptake studies clearly indicated that nerolidol induced cells oxidized compounds II, III, IV, V and ethyleneglycol. Based on these observations a new oxidative pathway for the degradation of I is suggested which envisages the epoxidation of the terminal double bond, opening of the epoxide and cleavage between C-2 and C-3 in a manner similar to the periodate oxidation of diol.

Nutritional evaluation of silage made from the toxic weed parthenium hysterophorus in animals

After ensilation, the toxic Compositae weed Parthenium hysterophorus was devoid of the toxic principle parthenin. Laboratory-scale ensilation indicated that no parthenin was detectable after 5 wk of anaerobic fermentation. For animal feeding studies, silage was made on a large scale from Parthenium mixed with maize or from Parthenium alone. Crossbred bull and buffalo bull calves were fed diets containing the silages, or control diet without silage, for 12 wk. The animals consumed both silages with relish, and body weight gains of silage-fed calves did not differ from those of the controls. The digestibilities of dry matter, fibre and nitrogen-free extract were greater with the control diet, but the biological value of proteins tended to be greater with the silage-containing diets. Haematological studies indicated no significant differences between experimental and control groups in selected parameters, except for a reduction in blood urea nitrogen in the animals fed silage. The possible causes for these biochemical alterations are discussed. Since the nutritive value of Parthenium silage compares favourably with the standard diet, and Parthenium seeds collected from the silage did not germinate, we suggest that ensilation can be used as an additional method in the containment and eradication of these plants, which grow wild in India.

Role of neutral metabolites in microbial conversion of 3beta-acetoxy-19-hydroxycholest-5-ene into estrone

Biotransformation of 3 beta-acetoxy-19-hydroxycholest-5-ene (19-HCA, 6 g) by Moraxella sp. was studied. Estrone (712 mg) was the major metabolite formed. Minor metabolites identified were 5 alpha-androst-1-en-19-ol-3,17-dione (33 mg), androst-4-en-19-ol-3,17-dione (58 mg), androst-4-en-9 alpha,19-diol-3,17-dione (12 mg), and androstan-19-ol-3,17-dione (1 mg). Acidic metabolites were not formed. Time course experiments on the fermentation of 19-HCA indicated that androst-4-en-19-ol-3,17-dione was the major metabolite formed during the early stages of incubation. However with continuing fermentation its level dropped, with a concomitant increase in estrone. Fermentation of 19-HCA in the presence of specific inhibitors or performing the fermentation for a shorter period (48 h) did not result in the formation of acidic metabolites. Resting-cell experiments carried out with 19-HCA (200 mg) in the presence of alpha,alpha'-bipyridyl led to the isolation of three additional metabolites, viz., cholestan-19-ol-3-one (2 mg), cholest-4-en-19-ol-3-one (10 mg), and cholest-5-en-3 beta,19-diol (12 mg). Similar results were also obtained when n-propanol was used instead of alpha,alpha'-bipyridyl. Resting cells grown on 19-HCA readily converted both 5 alpha-androst-1-en-19-ol-3,17-dione and androst-4-en-19-ol-3,17-dione into estrone. Partially purified 1,2-dehydrogenase from steroid-induced Moraxella cells transformed androst-4-en-19-ol-3,17-dione into estrone and formaldehyde in the presence of phenazine methosulfate, an artificial electron acceptor. These results suggest that the degradation of the hydrocarbon side chain of 19-HCA does not proceed via C-22 phenolic acid intermediates and complete removal of the C-17 side chain takes place prior to the aromatization of the A ring in estrone. The mode of degradation of the sterol side chain appears to be through the fission of the C-17-C-20 bond. On the basis of these observations, a new pathway for the formation of estrone from 19-HCA in Moraxella sp. has been proposed.