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81.
Background
Dihydrolinalool and terpineol are sources of fragrances that provide a unique volatile terpenoid alcohol of low toxicity and thus are widely used in the perfumery industry, in folk medicine, and in aromatherapy. They are important chemical constituents of the essential oil of many plants. Previous studies have concerned the biotransformation of limonene by Pseudomonas putida. The objective of this research was to study biotransformation of myrcene by Pseudomonas aeruginosa. The culture preparation was done using such variables as different microbial methods and incubation periods to obtain maximum cells of P. aeruginosa for myrcene biotransformation.Results
It was found that myrcene was converted to dihydrolinalool and 2,6-dimethyloctane in high percentages. The biotransformation products were identified by Fourier-transform infrared spectroscopy (FT-IR), ultraviolet (UV) analysis, gas chromatography (GC), and gas chromatography-mass spectroscopy (GC-MS). Comparison of the different incubation times showed that 3 days was more effective, the major products being 2,6-dimethyloctane (90.0%) and α-terpineol (7.7%) and comprising 97.7%. In contrast, the main compounds derived for an incubation time of 1.5 days were dihydrolinalool (79.5%) and 2,6-dimethyloctane (9.3%), with a total yield of 88.8%. 相似文献82.
Divya Sharma Alka Verma Yogendra Kumar Prajapati Vivek Singh Jai Prakash Saini 《Optical and Quantum Electronics》2013,45(2):105-114
In this study, an efficient method is discussed to analyze the multilayer planar waveguides with double negative guided (DNG) and double positive material as guiding film. Here, among various lossless multilayer planar waveguide structures, only three layer and five layer structures are discussed. For these structures, guided dispersion characteristic, along with electric field distribution of TM modes are numerically analyzed and compared. This analysis enables an effective comparison of guided modal properties of various modes and results in a better understanding of the multilayer planar waveguide with DNG as guiding film. 相似文献
83.
Varughese Philip V. Suni M. R. Prathapachandra Kurup 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o856-o858
The molecule of the title compound, C19H17N5S, adopts a Z configuration about the azomethine bond and exists as the thione tautomer. The overall structure of the molecule is distributed in four different planes. An intramolecular hydrogen bond involving the pyridyl N atom and the H atom attached to the hydrazine N atom leads to the formation of a six‐membered ring. 相似文献
84.
High pressure Raman spectroscopic investigations have been carried out on rare earth orthovanadate LuVO4 upto 26 GPa. Changes in the Raman spectrum around 8 GPa across the reported zircon to scheelite transition are investigated in detail and compared with those observed in other vanadates. Co-existence of the zircon and scheelite phases is observed over a pressure range of about 8-13 GPa. The zircon to scheelite transition is irreversible upon pressure release. Subtle changes are observed in the Raman spectrum above 16 GPa which could be related to scheelite ↔ fergusonite transition. Pressure dependencies of the Raman active modes in the zircon and the scheelite phases are reported. 相似文献
85.
Malachite green adsorption characteristics of magnetic beads have been investigated by batch and column methods. The maximum removal percentage of malachite green (93.9 %) was obtained at pH 7–8. The Langmuir and Freundlich isotherms were used to investigate the adsorption equilibrium. It was found that the Freundlich model provides the best correlation with the equilibrium. In the column method, the BDST model was used to obtain an empirical relationship for the design of the adsorption column. The characterization of the prepared magnetic beads has been accomplished by FTIR, SEM, and XRD measurements. 相似文献
86.
87.
B N Raja Sekhar S Padmanabhan Aparna Shastri P Meenakshi Raja Rao M B Kurup K G Prasad 《Pramana》1998,50(3):231-237
Beam-foil spectrum of fluorine was recorded in the wavelength region of 2000–4500 Å using F+ ion beams of energies ranging from 216 to 296 KeV. Some of the spectral lines of fluorine observed during the present investigation are hitherto unknown. Mean lifetimes of a few of the excited levels of F II and F III are reported for the first time. 相似文献
88.
Heterocyclic base adducts of salicylaldehyde N(4)- cyclohexylthiosemicarbazone(H2L) copper(II) complexes have been synthesized
and characterized. I.r., electronic and e.s.r. spectra of the complexes, as well as i.r., electronic and 1H- and 13C-n.m.r.
spectra of the thiosemicarbazone have been obtained. Based on e.s.r. studies, all possible parameters have been calculated.
The g values, calculated for all the complexes in frozen solution, indicate the presence of the unpaired electron in the dx2−y2
orbital. The metal–ligand bonding parameters evaluated showed strong in-plane σ- and in-plane π-bonding. The magnetic and
spectroscopic data indicate a square-planar geometry for the four-coordinate and a distorted square-pyramidal structure for
the five-coordinate complexes. From cyclic voltammetric data quasireversible copper(II)/copper(I) couples are observed for
the complexes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
89.
Devendra Kumar Uday Razdan Alka D. Gupta 《Journal of polymer science. Part A, Polymer chemistry》1993,31(9):2319-2331
A proton-NMR study of the condensation reaction (step 1) of 4-(3′-aminophenoxy)phthalonitrile (4-3′APPN) ( I ) in an aprotic solvent with various aromatic dianhydrides demonstrated the formation of the corresponding bisamic acid within 5–10 min. There was no effect of the electron affinity of the used aromatic dianhydrides on the time of the condensation reaction and also no charge-transfer complex formation was indicated. Proton-NMR study of the synthesized bisaryloxy-bisimido-bisphthalonitriles at 250.1 MHz has revealed general findings for their NMR characterization. The coupling constant (J) value for the ortho-coupled protons of the phthalonitrile ring of the 4–3′-APPN portion is 8.8 ± 0.05 Hz and that for the ortho-coupled protons of the aminophenoxy ring of 4–3′-APPN is 8.1 ± 0.05 Hz. The coupling constant (J) values for ortho-coupled protons of the dianhydride portion range from 8.1 to 7.5 Hz. Various thermally polymerizable bisaryloxybisimido-bisphthalonitriles (BBBP) ( X, XI, XII , and XIII ) containing dimethylsilane, hexafluoroisopropylidene, ether, and keto groups, suitable for the development of thermooxidative stable, void-free composites, were synthesized by two methods. In method 1,4–3′-APPN ( I ) in N,N-dimethylacetamide (DMAC) was condensed (step 1) with bis(3,4-dicarboxyphenyl)dimethylsilane dianhydride (SIDA) ( II ), 4, 4′-hexafluoroisopropylidenediphthalic anhydride (6FDA) ( III ), bis(3,4-dicarboxyphenyl)ether dianhydride (ODPA) ( IV ), and 3,4,3′,4′-benzophenonetetracarboxylic dianhydride (BTDA) ( V ), respectively, to give the corresponding bisamic acids. Thermal cyclodehydration of the intermediate bisamic acid at 160°C gave the bisphthalonitriles. In method 2, the second step of thermal cyclodehydration was performed in situ in refluxing toluene. The characterization of the synthesized bisaryloxy-bisimido-bisphthalonitriles (BBBP) was performed using FT-IR, 1H-NMR, 13C-NMR, mass spectroscopy, and elemental analysis. A preliminary study indicated that thermal-polymerization of these bisphthalonitriles (BBBP) gave tough, thermosetting polymers, useful for high-temperature applications. © 1993 John Wiley & Sons, Inc. 相似文献
90.
Anwar Usman Ibrahim Abdul Razak Suchada Chantrapromma Hoong‐Kun Fun A. Sreekanth S. Sivakumar M. R. Prathapachandra Kurup 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):m461-m463
One half of the molecule of the title complex, [Mn(C14H13N4S)2], is related to the other half by a twofold axis passing through the Mn atom. This high‐spin Mn atom is six‐coordinated, in an octahedral geometry, by the azomethine N, the pyridyl N and the thiolate S atom of two planar 1‐(pyridin‐2‐yl)ethanone N(4)‐phenylthiosemicarbazone ligands. In the crystal, the molecules are interconnected by N—H?S and C—H?N interactions, forming a three‐dimensional network. 相似文献