The recently reported growth-promoting ability of 3-methyl-eneoxindole was examined in order to test the hypothesis that indole-3-acetic acid acts as a growth promoter only after oxidative conversion to 3-methyleneoxindole. Methyleneoxindole was synthesized from indole-3-acetic acid and N-bromosuccinimide, and its identity was confirmed by ultraviolet absorption, infrared absorption, mass spect...

Three simple, accurate, and sensitive colorimetric methods for the determination of cimetidine (Cim) in pure form, in dosage forms, and in the presence of its oxidative degradates were developed. These methods are indirect, involve the addition of excess oxidant [N-bromosuccinimide (NBS) for method A; cerric sulfate [Ce(SO4)2] for methods B and C] of known concentration in acid medium to Cim, a...

Two simple and accurate methods are described for the determination of piroxicam and tenoxicam in their pharmaceutical preparations. The spectrophotometric method involves the oxidation of these drugs with potassium iodate in acid medium with the liberation of iodine and subsequent extraction with cyclohexane followed by measuring the absorbance at lambda=522 nm. Beer's law is obeyed in the con...

Bromination of aralkyl ketones using N-bromosuccinimide in presence of active Al2O3 provided either α -monobrominated products in methanol at reflux or mononuclear brominated products in acetonitrile at reflux temperature with excellent isolated yields depending on the nature of substrate employed. The α -bromination was an exclusive process when aralkyl ketones containing moderate activating/d...

Functional glycomics has been impeded by the lack of inexpensive enzymatic and mild chemical methods to acquire natural glycans in significant amounts. In this study, we have developed a new strategy we term "threshing and trimming" (TaT) to quickly obtain N-glycans from glycoproteins and animal tissues. TaT employs low-cost Pronase to degrade peptides and N-bromosuccinimide (NBS) to effect oxi...

HE PURPOSES OF THE PRESENT PAPER are to describe some new sensitive tests suitable for the detection of bile in biologic fluids which overcome the defects demonstrated in procedures described in most standard texts, and also to confirm the experiments of C. E. May et at. (1). The sensitivity of the proposed oxidation tests to detect bilirubin, viz. ferricyanide, molybdate, N-bromosuccinimide (2...

The phosphorylation of H1 histone subtypes was studied in 3 Chinese hamster cell lines (CHO, V79, and CHW). Chromatographic resolution of H1 subtypes showed that all 3 cell lines contained 1 homologous (coeluting) H1 subtype (CHO-1, V79-1, and CHW-1) while V79 and CHW cells contained 2 additional H1 subtypes not found in CHO cells (V79-2,3 and CHW-2,3). N-Bromosuccinimide cleavage of 32P-labele...

A novel and highly sensitive method for the determination of phenformin over the range of 6 x 10(-9) - 1 x 10(-5) g ml(-1) in pharmaceutical formulations with flow-injection chemiluminescence (CL) detection is proposed. The method is based on the CL produced during the oxidation of N-bromosuccinimide (NBS) in an alkaline medium in the presence of fluorescein as an effective energy transfer agen...

We have monitored the membrane-bound channel and nonchannel conformations of gramicidin utilizing red-edge excitation shift (REES), and related fluorescence parameters. In particular, we have used fluorescence lifetime, polarization, quenching, chemical modification, and membrane penetration depth analysis in addition to REES measurements to distinguish these two conformations. Our results show...

Simple and sensitive spectrophotometric methods for the determination of midazolam (MID) are proposed. The methods are based on the bromination of the drug using N-bromosuccinimide (NBS) and the excess oxidant is determined by either malachite green (MG) or safranin O (SO), the absorbances of which are measured at 617 or 522 nm for MID-MG and MID-SO, respectively. Under the optimized experiment...