Detection Of Resorcinol Research Articles

Hydrothermally Grown MoS2 as an Efficient Electrode Material for the Fabrication of a Resorcinol Sensor.

Recently, the active surface modification of glassy carbon electrodes (GCE) has received much attention for the development of electrochemical sensors. Nanomaterials are widely explored as surface-modifying materials. Herein, we have reported the hydrothermal synthesis of molybdenum disulfide (MoS2) and its electro-catalytic properties for the fabrication of a resorcinol sensor. Structural properties such as surface morphology of the prepared MoS2 was investigated by scanning electron microscopy and phase purity was examined by employing the powder X-ray diffraction technique. The presence of Mo and S elements in the obtained MoS2 was confirmed by energy-dispersive X-ray spectroscopy. Finally, the active surface of the glassy carbon electrode was modified with MoS2. This MoS2-modified glassy carbon electrode (MGC) was explored as a potential candidate for the determination of resorcinol. The fabricated MGC showed a good sensitivity of 0.79 µA/µMcm2 and a detection limit of 1.13 µM for the determination of resorcinol. This fabricated MGC also demonstrated good selectivity, and stability towards the detection of resorcinol.

Metabolism in sheep of gallic acid, tannic acid and hydrolysable tannin from Terminalia oblongata

Hydrolysable tannin (HT) is present in a variety of tropical browse plants, some of which poison ruminants. In an attempt to clarify the toxic action, we investigated the major urinary metabolites resulting from dosing of sheep with the HT, tannic acid; its simplest and major phenolic component, gallic acid; and the HT-containing and toxic Terminalia oblongata. Phenolic metabolites were separated by HPLC and their structures investigated by proton and 13C NMR. Gallic acid was less toxic (w/w) than tannic acid. Comparison of urinary metabolites from rumen and abomasal administration indicated that decarboxylation and reductive dehydroxylation of phenolics occurred principally in the rumen and a significant proportion was totally degraded. Rumen metabolism appeared to prevent toxicity from gallic and tannic acid at dose rates of <0.4 g/kg liveweight per day. Resorcinol glucuronide and the glucuronide of 2-carboxy-2'4'4,6,-tetrahydroxy diphenyl 2, 2'-lactone were the major urinary metabolites derived from tamic acid and probably from yellow-wood HT while resorcinol glucuronide was the major product of gallic acid metabolism. Minor urinary metabolites included unconjugated pyrogallol, resorcinol and phloroglucinol. Toxicity appeared to correlate with the passage of the diphenyl lactone metabolite, presumably arising from the degradation of the hexahydroxydiphenic acid moiety in HT. The current studies indicate that yellow-wood toxicity probably occurs under circumstances when animals ingest leaf containing high levels of HT without prior conditioning. A diagnosis of yellow-wood toxicity could be confirmed by the detection of resorcinol and diphenyl lactone metabolites in urine of affected ruminants.

STUDIES ON BRAIN GANGLIOSIDES. II. ANALYSIS OF HUMAN BRAIN GANGLIOSIDE FRACTIONS OBTAINED BY PREPARATIVE THIN-LAYER CHROMATOGRAPHY.

Purified gangliosides prepared by the tetrahydrofuran procedure were chromatographed on thin layers of silica gel, using a solvent system of chloroform–methanol −7% ammonia, 55/40/10, v/v/v. A resorcinol detection spray revealed a complex reproducible pattern of five major and several minor components which was similar to that observed in crude lipid extracts of brain. The major components were isolated by a preparative thin-layer technique as a slow fraction containing three components, an intermediate, and a fast fraction. Analysis gave N-acetylneuraminic acid contents of 33.4%, 26.6%, and 15.8% for the slow, intermediate, and fast fractions and the following molar ratios of ceramide:glucose:galactose:hexosamine:N-acetylneuraminic acid: slow, 1.0:0.9:3.2:1.0:2.6; intermediate, 1.0:0.8:2.7:0.8:1.7; and fast, 1.0:0.8:2.2:0.7:0.8.