Vanillin analog--vanillyl mandelic acid, a novel specific inhibitor of snake venom 5'-nucleotidase

Proteomic Identification and Quantification of Snake Venom Biomarkers in Venom and Plasma Extracellular Vesicles

The global exploration of snakebites requires the use of quantitative omics approaches to characterize snake venom as it enters into the systemic circulation. These omics approaches give insights into the venom proteome, but a further exploration is warranted to analyze the venom-reactome for the identification of snake venom biomarkers. The recent discovery of extracellular vesicles (EVs), and their critical cellular functions, has presented them as intriguing sources for biomarker discovery and disease diagnosis. Herein, we purified EV’s from the snake venom (svEVs) of Crotalus atrox and C. oreganus helleri, and from plasma of BALB/c mice injected with venom from each snake using EVtrap in conjunction with quantitative mass spectrometry for the proteomic identification and quantification of svEVs and plasma biomarkers. Snake venom EVs from C. atrox and C. o. helleri were highly enriched in 5′ nucleosidase, L-amino acid oxidase, and metalloproteinases. In mouse plasma EVs, a bioinformatic analysis for revealed upregulated responses involved with cytochrome P450, lipid metabolism, acute phase inflammation immune, and heat shock responses, while downregulated proteins were associated with mitochondrial electron transport, NADH, TCA, cortical cytoskeleton, reticulum stress, and oxidative reduction. Altogether, this analysis will provide direct evidence for svEVs composition and observation of the physiological changes of an envenomated organism.

Effect and Mechanism of Aluminum(III) for Guaiacol-Glyoxylic Acid Condensation Reaction in Vanillin Production

3-methoxy-4-hydroxymandelic acid (VMA) was the critical intermediate for the synthesis of vanillin by the glyoxylic acid method. Meanwhile, a valuable byproduct (2-hydroxy-3-methoxy-mandelic acid, o-VMA) was obtained during the reaction. Al3+ was found to be a helpful catalyst in increasing the selectivity for VMA and o-VMA. In the presence of Al3+, the selectivity for VMA and o-VMA increased from 83 to 88% and from 3 to 8%, respectively, while that of the helpless byproduct 2-hydroxy-3-methoxy-1,5-mandelic acid (di-VMA) decreased from 14% to less than 4%. The kinetics based on the kinetic equation of the condensation reaction was studied by the initial concentration method. The results indicated that the involvement of Al3+ could reduce the activation energy of the reaction on the basis of the Arrhenius equation. Combined with thermogravimetric analysis, in situ Fourier transform-infrared spectroscopy, and 1H NMR research, Al3+ was found to interact with guaiacol through Al-O and Al···H, which further improved the selectivity of the VMA and o-VMA and reduced the selectivity of di-VMA by adding the electronegativity of the ortho- and para-positions of hydroxyl groups of guaiacol.

Identification of potential transmembrane protease serine 4 inhibitors as anti-cancer agents by integrated computational approach

Transmembrane protease serine 4 is a well known cell surface protease facilitating the extracellular matrix degradation and epithelial mesenchymal transition in hepatocellular carcinoma. Henceforth targeting transmembrane protease serine 4 is strongly believed to provide therapeutic intervention against hepatocellular carcinoma. Owing to lack of crystal structure for human transmembrane protease serine 4, we predicted its three dimensional structure for the first time in this study. Experimentally proven inhibitor-Tyroserleutide (TSL) against hepatocellular carcinoma via transmembrane protease serine 4 was used as a benchmark to identify structurally similar candidates from PubChem database to create the TSL library. Virtual screening of TSL library against modeled transmembrane protease serine 4 revealed the top four potential inhibitors. Further binding free energy (ΔGbind) analysis of the potential inhibitors revealed the best potential lead compound against transmembrane protease serine 4. Drug likeliness nature of the top four potential hits were additionally analyzed in comparison to TSL to confirm on the best potential lead compound with the highest % of human oral absorption. Consequently, e-pharmacophore mapping of the best potential lead compound yielded a six point feature. It was observed to contain four hydrogen bond donor sites (D), one positively ionizable site (P) and one aromatic ring (R). Such e-pharmacophore insight obtained from structural determinants by integrated computational analysis could serve as a framework for further advancement of drug discovery process of new anti-cancer agents with less toxicity and high specificity targeting transmembrane protease serine 4 and hepatocellular carcinoma.