Hydrogen bonding interactions between arsenious acid and dithiothreitol/dithioerythritol at different pH values: A computational study under explicit solvent model

Sulfhydryl compounds are regarded as potential functional monomers for arsenious acid imprinted polymers due to their high affinity to arsenious acid in aqueous solution. However, the recognition and binding mechanism...

Short Communication: Optimization of extraction of sulfhydryl compounds from several legumes seeds in Indonesia with various ethanol concentrations

Wardatun S, Harahap Y, Mun’im A. 2020. Short Communication: Optimization of extraction of sulfhydryl compounds from several legumes seeds in Indonesia with various ethanol concentrations. Biodiversitas 21: 1060-1064. Leucaena leucocephala (Lam.) de Wit (petai Cina), Parkia speciosa Hassk. (petai), and Archidendron jiringa (Jack) I.C. Nielsen (jengkol) seeds extracts contain sulfhydryl compounds and have various therapeutic properties. The main objective of this research was to compare the effect of various ethanol concentration on the yield of extract and levels of sulfhydryl compounds from leguminous seeds. Dried seeds were macerated at room temperature (25°C) with a ratio of solids and solvents was 1:10. The solvent concentrations used were 30%, 50%, 70% and 96% ethanol. The yield of extract was expressed as the ratio of the weight of extract to the weight of dried seeds, the level of sulfhydryl compound was expressed as reduced L-glutathione (GSH) equivalent. The level of sulfhydryl compounds was determined by Ellman reagent and further analyzed using a spectrophotometer at 411 nm wavelength. Stink bean produced the highest yield of extract, while the highest level of sulfhydryl compounds was obtained from petai cina seed extract. The concentration of ethanol gave a significant difference to the yield of extract and the level of sulfhydryl compounds. The results showed that ethanol concentration affected the efficiency of the extraction of total sulfhydryl compounds and the yield of the extract on leguminous seeds.

Glutathione promoted Fenton degradation: a cocatalyst based on the –HS/–S–S– cycle with hydroxyl radicals

Sulfhydryl compounds effectively promote Fenton degradation through the establishment of the –HS/–S–S cycle with hydroxyl radicals.

Synthesis of Silane-Based Poly(thioether) via Successive Click Reaction and Their Applications in Ion Detection and Cell Imaging

A series of poly(thioether)s containing silicon atom with unconventional fluorescence were synthesized via successive thiol click reaction at room temperature. Although rigid π-conjugated structure did not exist in the polymer chain, the poly(thioether)s exhibited excellent fluorescent properties in solutions and showed visible blue fluorescence in living cells. The strong blue fluorescence can be attributed to the aggregation of lone pair electron of heteroatom and coordination between heteroatom and Si atom. In addition, the responsiveness of poly(thioether) to metal ions suggested that the selectivity of poly(thioether) to Fe3+ ion could be enhanced by end-modifying with different sulfhydryl compounds. This study further explored their application in cell imaging and studied their responsiveness to Fe3+ in living cells. It is expected that the described synthetic route could be extended to synthesize novel poly(thioether)s with superior optical properties. Their application in cell imaging and ion detection will broaden the range of application of poly(thioether)s.

Gastroprotective Effects of Paeonia Extract Mixture HT074 against Experimental Gastric Ulcers in Rats

Background. Paeonia extract mixture HT074 is a standardized multiherbal mixture comprising extracts from Inula britannica flowers and Paeonia lactiflora roots, which are used to treat digestive disorders in traditional Korean medicine. This study was focused on elucidating the underlying mechanisms of the gastroprotective effects of HT074 in different gastric ulcer models. Methods. Gastric lesions were induced in rats by an HCl/EtOH solution, water immersion-restraint stress (WIRS), and indomethacin. Gastric secretions were studied in pylorus-ligated rats, while mucus secretions were assessed by measuring alcian blue-binding capacity of mucus in the rat model of HCl/EtOH-induced gastric ulcer. Additionally, the involvement of nitric oxide (NO) and sulfhydryl compounds in HT074-mediated mucosal protection was elucidated using their inhibitors, i.e., NG-nitro- L-arginine methyl ester hydrochloride (L-NAME) and N-ethylmaleimide (NEM), respectively. Furthermore, the effects on indomethacin-induced cell death and prostaglandin E2 (PGE2) levels were assessed in AGS cells. Results. Oral administration of HT074 significantly decreased gastric lesions induced by HCl/EtOH, WIRS, and indomethacin. Furthermore, it significantly decreased the volume, acidity, and total acidity of gastric juice in pylorus-ligated rats and increased the alcian blue-stained gastric mucus in HCl/EtOH-induced gastric ulcer in rats. Pretreatment with NEM abolished the gastroprotective effects of HT074, while L-NAME did not. In AGS cells, HT074 significantly reduced indomethacin-induced cell death and increased the PGE2 levels. Conclusions. These findings suggest that HT074 has gastroprotective effects against various ulcerogens, including HCl/EtOH, immersion stress, and NSAIDs. These effects are attributed to the inhibition of gastric secretions and preservation of the gastric mucosal barrier by increased mucus production, which is partially mediated through endogenous sulfhydryl compounds and PGE2. Based on these findings, we propose that HT074 may be a promising therapeutic agent for gastritis and gastric ulcer.

Gastroprotection of Calein D against Ethanol-Induced Gastric Lesions in Mice: Role of Prostaglandins, Nitric Oxide and Sulfhydryls

Peptic ulcers are currently treated with various drugs, all having serious side effects. The aim of this study was to evaluate the gastroprotective activity of calein D (from Calea urticifolia), a sesquiterpene lactone with a germacrane skeleton. Gastric lesions were induced in mice by administering ethanol (0.2 mL) after oral treatment with calein D at 3, 10 and 30 mg/kg, resulting in 13.15 ± 3.44%, 77.65 ± 7.38% and 95.76 ± 2.18% gastroprotection, respectively, to be compared with that of the control group. The effect found for 30 mg/kg of calein D was not reversed by pretreatment with NG-nitro-l-arginine methyl ester (l-NAME, 70 mg/kg, ip), indomethacin (10 mg/kg, sc) or N-ethylmaleimide (NEM, 10 mg/kg, sc). Hence, the mechanism of action of calein D does not involve NO, prostaglandins or sulfhydryl compounds. Calein D was more potent than carbenoxolone, the reference drug. The findings for the latter are in agreement with previous reports.