Inhibition of thermal induced protein denaturation of extract/fractions of <i>Withania somnifera</i> and isolated withanolides

<div><p>This study describes the <i>in vitro</i> inhibition of protein denaturation of extract/fractions of <i>Withania somnifera</i> and isolated withanolides including 20β hydroxy-1-oxo(22<i>R</i>)-witha-2,5,24 trienolide (<b>1</b>), (20<i>R</i>,22<i>R</i>-14α,20α)-dihydroxy-1-oxowitha-2,5,16,24 tetraenolide (<b>2</b>). The results showed that the extract/fractions of the plant evoked profound inhibitory effect on thermal-induced protein denaturation. The chloroform fraction caused the most dominant attenuation of 68% at 500 μg/mL. The bioactivity-guided isolation from chloroform fraction led to the isolation of compounds <b>1</b> and <b>2</b> that showed profound protein inhibition with 78.05% and 80.43% effect at 500 μg/mL and thus strongly complimented the activity of extract/fractions. In conclusion, extract/fractions of <i>W. somnifera</i> possessed strong inhibition of protein denaturation that can be attributed to these isolated withanolides.</p></div

Pistagremic acid, a novel β-secretase enzyme (BACE1) inhibitor from <i>Pistacia integerrima</i> Stewart

<div><p>A new triterpenic compound named pistagremic acid (PA) was once again isolated from <i>Pistacia</i><i>integerrima</i>. The β-secretase inhibition study was carried out. Compound PA was found significantly active against β-secretase enzyme (BACE1) with IC₅₀ value of 350 ± 2 nM in comparison to the standard inhibitors [Asn670, Sta671, Val672]-amyloid-β/A4 precursor protein 770 fragment 662–675 (IC₅₀ = 290.71 ± 1 nM). The selectivity of this compound was also evaluated against the acetylcholinesterase and butyrylcholinesterase enzymes. Interestingly compound PA was found to be inactive against them and showed selectivity towards β-secretase enzyme (BACE1).</p></div

Impact of Geometric Parameters, Charge, and Lipophilicity on Bioactivity of Armed Quinoxaline, Benzothiaole, and Benzothiazine: Pom Analyses of Antibacterial and Antifungal Activity

<div><p></p><p>A series of four different armed heterocyclic candidates; 1-(2-methyl-2,3-dihydro-1,3-benzothiazol-2-yl)acetone (<b>2</b>), 1-(3-methyl-4H-1,4-benzothiazin-2-yl)ethanone (<b>3</b>), 2-[(2-aminophenyl)dithio]aniline (<b>4</b>), and 3-hydroxy-3-methyl-4-(3-methyl-2-quinoxalinyl)-2-butanone (<b>5</b>) have been prepared and their microbial activities were evaluated. A correlation of the structure and activities relationships of these compounds with respect to molecular modeling, Lipinski Rule of Five, drug likeness, toxicity profiles, and other physico-chemical properties of drugs are described and verified experimentally.</p></div