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A new stability indicating reverse phase HPLC method has been developed and validated as per International Conference on Harmonization guidelines for the determination of sacubitril‐valsartan premix stereoisomers, namely, (2R)‐valsartan, (2S,4S)‐sacubitril, (2R,4S)‐sacubitril, and (2R,4R)‐sacubitril. Primarily, stability indicating separation study was done on reverse phase LC conditions; it was described by peak homogeneity of sacubitril–valsartan and its stereoisomers. Cellulose tris(4‐methylbenzoate) packing column Chiralcel OJ‐RH(150 mm × 4.6 mm), 5 μm provided better resolution than those of amylose based stationary phase's. Resolution between two arbitrary adjacent analyte was found to be more than 2.0 with 0.1% trifluoroacetic acid in water as mobile phase‐A and mobile phase‐B consisting of acetonitrile, methanol, and trifluoroacetic acid (90:10:0.1, v/v/v). Gradient elution was performed at a flow rate of 1.0 ml/min, column temperature 20°C, injection volume 10 μl, UV detection at 254 nm and run time was 52 min. The detector response linearity of stereoisomers found to be linear (R2 ≥ 0.9998), limit of detection (0.290 μg/ml, 0.122 μg/ml, 0.123 μg/ml, and 0.124 μg/ml), and limit of quantification (0.878 μg/ml, 0.370 μg/ml, 0.373 μg/ml, and 0.375 μg/ml), respectively. Percentage recovery was found to be 98–105. Finally, the proposed method is user friendly and can be used in bulk drugs analysis. [ABSTRACT FROM AUTHOR]

Reports on a study in which gonadotropin (GTH) was purified from the pituitaries of the Pacific chinook salmon using a combination of stepwise ethanol precipitation and concanavalin-A affinity chromatography. Reverse-phase high-performance liquid chromatography; Screening of an enriched cDNA library for the β-GTH genes using two synthetic oligonucleotides; Effect of testosterone implantation on pituitary PTH and β-GTH mRNA; Corresponding increase in both the pituitary GTH and mRNA levels.

One antibacterial activity fraction from an immunized dipteran insect, Bactrocera dorsalis, was isolated and purified by prepurification, ion-exchange chromatography, gel filtration chromatography and reverse-phase high performance liquid chromatography (HPLC). The final purified fraction was checked on the Smart system HPLC and was judged as a pure fraction. The results of physical and biological analysis revealed that this fraction is heat stable and showed strong activities against Gram-positive bacterial growth. It possesses antibicrobial peptide properties and is worth further investigation. [ABSTRACT FROM AUTHOR]

The major peptide from the sinus gland of the terrestrial isopod Armadillidium vulgare (Crustacea) has been extracted and purified by reverse-phase HPLC. This neuropeptide exhibited a high hyperglycemic activity' and was therefore named A. vulgare crustacean hyperglycemic hormone (Arv-CHH). Its average molecular mass measured by mass spectrometry was 8729.3 Da. Its complete amino acid sequence was determined by a combination of Edman degradation and mass spectrometry. The N-terminal amino acid was found to be unblocked, the C-terminal residue was found amidated and none of the other 72 residues was affected by any post-translational modification. Disulfide bond assignment was made unambigously by mass spectrometry and Edman degradation was performed on peptides produced by enzymatic cleavage. Relationships with other, similar neuropeptides from decapod sinus glands are discussed. [ABSTRACT FROM AUTHOR]