Microbial transformation of dehydroepiandrosterone

Transformation of dehydroepiandrosterone (DHEA) (1) was carried out by a plant pathogen Rhizopus stolonifer, which resulted in the production of seven metabolites. These metabolites were identified as 3beta,17beta-dihydroxyanandrost-5-ene (2), 3beta,17beta-dihydroxyandrost-4ene (3), 17beta-hydroxyandrost-4-ene-3-one (4), 3beta,11-dihydroxyandrost-4-ene-17-one (5), 3beta,7alpha-dihydroandrost-5-ene-17-one (6), 3A,7alpha,17beta-trihydroxyandrost-5-ene (7) and 11beta-hydroxyandrost-4,6-diene-3,17-dione (8). The structures of the transformed products were determined by the spectroscopic techniques.     

Study of ion–solvent interactions and activation energy of LiBr in DMSO,H<Subscript>2</Subscript>O and DMSO–H<Subscript>2</Subscript>O mixtures at various temperatures

The Jones–Dole B coefficients of the electrolyte Lithium bromide (LiBr), reference salts tetra butyl ammonium tetra phenyl borate (BU₄NBPh₄), tetra butyl ammonium bromide (BU₄NBr), and potassium chloride (KCl) in dimethylsulfoxide (DMSO), water, and DMSO–water mixtures were obtained at different temperatures range from 25 to 45 °C For this, the relative viscosities were measured for Lithium bromide (LiBr) and reference salts in DMSO, water, and DMSO–water mixtures at above-mentioned temperatures. The B coefficients of these electrolytes were behaved as structure makers in DMSO, while in H₂O and DMSO–H₂O mixtures, the B-coefficient values were less positive showing the weak structure-making effect. Ionic viscosity B coefficients allow us to assess the behavior of ions in the solvent mixtures. In this study it was observed that all the values of ionic B coefficient of (Li⁺) were positive and small showing the weak structure-making effects. It was also observed that Br⁻ ions maintain negative B coefficient values in all DMSO–H₂O mixtures, except in 60% DMSO mole fraction. From this it can be concluded that Br⁻ ion behaved as a structure breaker in water and in all DMSO–H₂O mixtures except in 60% DMSO mole fraction mixtures. The low B _± values of alkali metal ions and Br⁻ ions in water are due to the breakdown of the tetrahedral structural of water and the formation of strongly structured solvated ion. It is also observed that the values of the energy of activation of the flow for LiBr are greater in DMSO–water mixtures and in pure water than in DMSO. This may be due the presence of a network of hydrogen bonds which cause the hindrance in the flow of the solution of LiBr in DMSO–water mixtures and in pure water than in DMSO.     

Acoustic Prediction of Voice Type in Women with Functional Dysphonia

The categorization of voice into quality type (ie, normal, breathy, hoarse, rough) is often a traditional part of the voice diagnostic. The goal of this study was to assess the contributions of various time and spectral-based acoustic measures to the categorization of voice type for a diverse sample of voices collected from both functionally dysphonic (breathy, hoarse, and rough) (n=83) and normal women (n=51). Before acoustic analyses, 12 judges rated all voice samples for voice quality type. Discriminant analysis, using the modal rating of voice type as the dependent variable, produced a 5-variable model (comprising time and spectral-based measures) that correctly classified voice type with 79.9% accuracy (74.6% classification accuracy on cross-validation). Voice type classification was achieved based on two significant discriminant functions, interpreted as reflecting measures related to "Phonatory Instability" and "F(0) Characteristics." A cepstrum-based measure (CPP/EXP ratio) consistently emerged as a significant factor in predicting voice type; however, variables such as shimmer (RMS dB) and a measure of low- vs. high-frequency spectral energy (the Discrete Fourier Transformation ratio) also added substantially to the accurate profiling and prediction of voice type. The results are interpreted and discussed with respect to the key acoustic characteristics that contributed to the identification of specific voice types, and the value of identifying a subset of time and spectral-based acoustic measures that appear sensitive to a perceptually diverse set of dysphonic voices.     

Synthesis and photoswitching properties of azobenzene liquid crystals with a pentafluorobenzene terminal

The fluorine-substituted benzoate ester rod-shaped liquid crystals containing an azobenzene side chain linked with terminal double bonds were synthesized and characterized.The mesophase and photoswitching properties were determined by polarizing optical microscopy(POM),differential scanning calorimetry(DSC) and UV-visible spectrometry.The rod-shaped compound 4a having an odd number of carbon atoms in the alkyl chains exhibits nematic phase and SmA type phase whereas compound 4b having an even number of carbon atoms showed only nematic phase.Both fluorinecontaining compounds 4c and 4d showed only SmA type phases.The photoswitching properties of these compounds showed a rate of trans to cis isomerization ranging 19-20 s,whereas reverse process took around 230 min in solution.These materials may be ideal in the field of optically rewritable applications where both on and off rates should be crucial.     

Three Tyrosinase Inhibitors and Antioxidant Compounds from Salsola foetida

Phytochemical investigation on the whole plant of Salsola foetida resulted in the isolation of three new phenolic compounds 1, 2 , and 3 , which exhibit tyrosinase inhibition with moderate antioxidant activity. Compounds 1 – 3 inhibited tyrosinase with IC₅₀ 2.61, 1.85, and 0.40 μM , while exhibiting DPPH radical scavenging activity with IC₅₀ 383, 427 and 378 μM , respectively. The structures of 1, 2 , and 3 were determined by modern spectroscopic techniques.     

Influence of various series of additives on the clouding behavior of aqueous solutions of triblock copolymers

The cloud point (CP) studies on aqueous solutions of two ethylene oxide-propylene oxide triblock copolymers (EO)_2.5(PO)₃₁(EO)_2.5 and (EO)₁₃(PO)₃₀(EO)₁₃ with varying number of ethylene oxide (EO) units were carried out in the presence of series of additives, such as alkali, acids, ionic surfactants, alcohols, salts, and hydrotropes. The results of this study show that sodium hydroxide decreases the CP of the two copolymers. Acids increase the CP in the order hydrochloric acid > acetic acid > formic acid for both the triblock copolymers. Hydrotropes increase the CP, whereas salts decrease or increase the CP based on their salting-out/salting-in nature. Alcohols, which are polar organic additives, affect the CP of the two copolymers differently. The change in the CP of the triblock copolymers depends upon the structure and concentration of the additives and on the number of EO units of the two triblock copolymers.     

Chemical constituents of the aerial parts of Kalidium foliatum

Studies on the chemical constituents of the aerial parts of Kalidium foliatum have led to the isolation of three new and one known compounds. The structures of new constituents have been elucidated through spectral studies including 2D-NMR experiments (HMQC, HMBC, COSY, NOESY and J-resolved) and MS/MS fragmentation using Q-TOF mass spectrometer equipped with an ESI source as kalidiumoside C (=3beta-hydroxy-29-methylmalonoxy-olean-12-en-23,28-dioic acid-23-methyl-28-beta-D-glucopyranosyl ester; 1), kalidiunin (=3beta,23,29-trihydroxy-olean-12-en-28-methyl-oate; 2) and kalidiumoside D (=3beta,23,29-trihydroxyolean-12-en-28-oic acid-beta-D-glucopyranosyl ester; 3). The known compound was identified as 3beta,23,29-trihydroxy-olean-12-en-28-oic acid 4) through comparison of its spectral data with those reported in literature. Acid hydrolysis of both 2 and 3 yielded the known compound 4 providing a conclusive evidence of the proposed structures.