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- Author or Editor: A. Suresh x
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For the first time a simple, sensitive, rapid, precise and accurate HPTLC method has been established for quantification of belleric acid in Terminalia bellerica (TB) fruit pericarp and its formulations. Silica gel plates were used with toluene-ethyl acetate-methanol-formic acid 3:3:1.4:0.2 (v/v) as mobile phase, and densitometric evaluation was performed at 205 nm. The method was validated for precision, repeatability, and accuracy. Average recovery of belleric acid at three levels (98.67, 100.2, and 100.90%) showed the reproducibility of the method was excellent. The calibration plot was linear in the range 250–1250 ng per band. The method could be easily adapted for high-throughput screening and for quality control of TB and its formulations.
Abstract
The extraction of nitric acid by tri-n-butyl phosphate (TBP), tri-sec-butyl phosphate (TsBP) and tri-iso-amyl phosphate (TiAP) solutions in n-dodecane are reported. The results indicate that increase in carbon chain length of the alkyl group of the phosphate as well as introduction of branching near the phosphoryl (P=O) group of the phosphate do not affect significantly the extraction of nitric acid.
A wide variety of pigments, like chlorophyll, carotenoids and phycobiliproteins, which exhibit colours ranging from green, yellow, brown to red are present in algae. Increasing awareness of harmful effects of synthetic dyes and inclination of society towards the usage of natural products, such as plant / microbial based colours in food and cosmetics, has led to the exploitation of microalgae as a source of natural colours. Algal pigments have great commercial value as natural colorants in nutraceutical, cosmetics and pharmaceutical industry, besides their health benefits. Spirulina, Dunaliella capsules are now commonly prescribed health foods for improving vitality and longevity of human beings. This review describes the distribution, structure of these pigments in algae, with emphasis on specific techniques for extraction and purification, along with different methods of biomass production and commercially feasible techniques documented in literature. An overview of the industrial applications of these natural colouring agents in diagnostics, food and cosmetics industry is also provided.
Superior grain quality is the main goal of rice breeders because of its high commercial value. Progress in selection for grain quality with yield in harsh environments is markedly affected by environmental variation. The genotype by environmental (G × E) interaction influence on grain quality was analyzed in this study, comprised of 17 rice hybrids grown in six location- year environments. The objective of this study was to examine the influence of G × E interaction for grain quality in hybrid rice by using AMMI model. Results of the trial revealed that grain quality was highly influenced by environmental factors and brings out the suitability of specific genotype to specific location/season through the biplot. On the other hand, external environmental variables can be regressed on the environmental scores to lead to a useful biological interpretation of the interaction effects, which is not possible in additive effect models. The implications of these results for rice hybrids on grain quality in varied environmental location are discussed.
Summary
An isocratic RP-HPLC method has been developed and validated for simultaneous analysis of ambroxol hydrochloride (AMB) with cetirizine hydrochloride (CTZ) and of ambroxol hydrochloride (AMB) with levo-cetirizine dihydrochloride (LCTZ) in combined solid dosage forms. Formulations containing AMB with CTZ (tablets) and AMB with LCTZ (capsules) are used as antihistaminic H1 blockers. Chromatography was performed on a 250 mm × 4.6 mm, 5-μm particle size, C18 (ODS) column with a 45:30:30 (v/v) mixture of 30 mM aqueous ammonium sulphate (pH 5.5), acetonitrile, and methanol as mobile phase at a flow rate of 1 mL min−1. The detection wavelength was 230 nm and analysis was performed at room temperature. Hydrochlorothiazide was used as internal standard for both formulations. Plots of drug-to-internal standard peakarea ratios (response factor) against respective concentrations were linear in the range 3 to 20 μg mL−1 for AMB and in the range 1 to 11 μg mL−1 for CTZ and LCTZ. The method was precise (RSD < 2) and accurate for analysis of both drugs in pharmaceutical dosage forms. Statistical data and results from recovery studies were reported for both formulations.
Abstract
In this paper, advanced DC-Link (DCL) based reversing voltage type Multilevel Inverter (MLI) topologies by compensating the difficulties in the conventional MLIs are reviewed. These topologies consist of less switching components and driver circuits when compared with conventional MLIs predominantly in higher levels. Consequently, installation area, total cost and hardware difficulties are reduced by increasing the voltage levels. The unipolar based Pulse Width Modulation Schemes (PWMS) will improve DCL inverters performance. This paper presents unipolar Multi-Reference (MR) based sine and space vector PWMS with single triangular carrier wave for generating required levels in output voltage. Comparison between UMR sine and space vector PWMS for DCL inverter topologies is presented in terms of Fundamental Output Voltage (FOV) and Total Harmonic Distortion (THD). The research tries to establish the survey analysis for single-phase 7-level DCL based reversing voltage type MLI topologies with UMR based sine and space vector PWMs. Finally, to confirm the feasibility of proposed DCL-MLIs in terms of FOV and THD the simulation results are incorporated. Further, the prototype model is developed for single-phase 7-level DCL inverter with Field Programmable Gate Array (FPGA) based UMR sine and space vector PWMS to authenticate simulation results. The efficiency of the proposed cascaded MLI achieves the value of 99.003%.
