@article { ISI:000316636600004, title = {Biodegradation of phenol by the yeast candida tropicalis: an investigation by NMR spectroscopy}, journal = {Applied Biochemistry and Biotechnology}, volume = {169}, number = {7}, year = {2013}, month = {APR}, pages = {2029-2037}, publisher = {HUMANA PRESS INC}, address = {999 RIVERVIEW DRIVE SUITE 208, TOTOWA, NJ 07512 USA}, abstract = {

The process of phenol biodegradation by the yeast Candida tropicalis NCIM 3556 in aqueous medium was studied by H-1, C-13, and DOSY NMR techniques. Samples at regular intervals were centrifuged to separate the cells, and H-1 spectral data were collected at 400 MHz. Though a gradual decrease in the concentration of phenol was observed, after an incubation period of similar to 8 h, formation of any intermediate products could not be detected. Experiments carried out with uniformly C-13-labeled phenol also failed to detect formation of any carboxylic acid intermediates during degradation. The studies indicated that the phenol was completely degraded to carbon dioxide and water in approximately 20 h. Self-diffusion coefficient measurements showed that the lifetime of phenol in the bound form is too small to impart any change in its diffusion behavior and the intermediates formed are converted to carbon dioxide and water at a very fast rate.

}, keywords = {biocatalysis, Carboxylic acid, Diffusion, Enzyme, NMR spectroscopy, phenol}, issn = {0273-2289}, doi = {10.1007/s12010-013-0119-0}, author = {Phalgune, U. D. and Rajamohanan, P. R. and Gaikwad, B. G. and Varma, R. J. and George, S.} } @article {46610, title = {P2O5-mediated Friedel-Crafts acylation of activated arenes with carboxylic acid as acylating agent}, journal = {Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry}, volume = {59}, year = {2020}, month = {DEC}, pages = {1861-1867}, type = {Article}, abstract = {

P2O5 has been found to be a highly efficient and environmental friendly catalyst for the liquid-phase acylation of activated aromatic substrates giving aromatic ketones (45-93\%) in a regioselective manner. Both aromatic and aliphatic carboxylic acids can be employed as acylating source. The process is particularly demonstrated at 100 g scale in the case of anisole and acetic acid to produce 4-methoxyacetophenone.

}, keywords = {4-methoxyacetophenone, Carboxylic acid, Friedel-Crafts acylations, phosphorus pentoxide}, issn = {0376-4699}, author = {Kalshetti, Rupali G. and Mandle, Ram D. and Kamble, Sanjay P. and Sudalai, Arumugam} } @article {49222, title = {Direct oxidation of alcohols to carboxylic acids using simple and economical Pd@Glu-HTC catalyst: practical and scalable approach towards biomass based value added chemicals}, journal = {Biomass \& Bioenergy}, volume = {187}, year = {2024}, month = {AUG}, pages = {107290}, type = {Article}, abstract = {

Sustainable catalytic transformation of bio-based alcohols to high value-added fine chemicals is an important topic of research. This work described preparation of simple and economical Pd@Glu-HTC catalyst from biomass derived low cost D-glucose. Hydrothermal carbonization of glucose was carried out in first step to synthesize GluHTC support in a simpler, greener, economical and efficient manner followed by incorporation of palladium metal on surface of the catalyst in second step. The catalyst was characterized using techniques such as Fourier Transform Infrared Spectroscopy (FT-IR), Solid-state Cross-Polarization Magic Angle Spinning Carbon-13 (13C CPMAS), Energy-dispersive X-ray spectroscopy (EDAX), Powder X-ray diffraction (P-XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetric/Differential Thermal Analyzer (TG-DTA), Field emission scanning electron microscopy (FE-SEM) and High-resolution transmission electron microscopy (HR-TEM). The catalyst was evaluated for direct oxidation of alcohols to yield carboxylic acids and exhibited very good catalytic activity for wider substrate scope. Oxidation of alcohols was carried out using milder base, molecular oxygen and water as a solvent to achieve 92-99 \% excellent yields. The practical utility of current strategy was also studied for gram scale synthesis of bio-based value added industrially important chemicals such as furoic acid (flavouring agent and preservative in industry), 2, 5-furan-dicarboxylic acid (monomer to 100 \% fossil-free, recyclable polymer polyethylene furanoate (PEF), tetrahydro-2-furoic acid (production of many drugs) and vanillin (important product of flavor and fragrance industry). Pd@Glu-HTC catalyst was found to be reusable for four recycles and the catalytic performance was retained without any loss in its activity after four cycles.

}, keywords = {Bio-based chemicals, Carbonaceous catalyst, Carboxylic acid, Oxidation}, issn = {0961-9534}, doi = {10.1016/j.biombioe.2024.107290}, author = {Kirdant, Swapnali P. and Bankar, Shubham R. and Jadhav, Vrushali H.} }