Radical Scavenging, Proteases Activities, and Phenolics Composition of Bark Extracts from 21 Medicinal Plants

Stem barks derived from twenty-one medicinal plants were extracted in methanol (100%) and acetone-water (70 : 30 v/v) and at room as well as at reflux temperature conditions. Total phenolic contents, determined using FC (Folin Ciocalteu) reagent, ranged from 528 to 715 mg GAE/g of crude extract. 15 out of 21 plants showed DPPH activity more than 90% and the rest of plants exhibited the activity in the range of 87–89%. The methanolic extract of P. granatum obtained at room temperature showed the highest antiradical activity (96%). The extracts with similar % radical scavenging of DPPH∙ showed significant variation in EC50 value. Radical scavenging activity of E. rostrata, M. champaca, A. modesta, P. roxburghii, P. longifolia, E. suberosa, and F. infectoria was evaluated for the first time. A strong correlation between total phenols and antiradical activity was exhibited with R values ranging from 0.7580 to 0.8874 indicating a linear relationship The extracts phenolic composition was studied by HPLC. All extracts showed remarkable antioxidant activity (87 to 96%) while moderate activity was exhibited against protease (22 to 56%). Gallic acid, tannic acid, quercetin, rutin, catechin, hesperidin, and cinnamic acid were identified as the major phenolic acids in the extracts of selected medicinal plants

Crystal structure of catena-poly[[tri-methyltin(IV)]-μ-2-(2-nitrophenyl)-acetato-κ2O:O′]

The authors acknowledge the provision of funds for the purchase of a diffractometer and encouragement by Dr Muhammad Akram Chaudhary, Vice Chancellor, University of Sargodha, Pakistan.Peer reviewedPublisher PD

(5Z)-5-(2-Hydroxy­benzyl­idene)-3-phenyl-2-thioxo-1,3-thia­zolidin-4-one

In the title compound, C16H11NO2S2, the dihedral angles between the heterocyclic ring and the phenyl and anilinic benzene rings are 9.68 (13) and 79.26 (6)°, respectively, and an intra­molecular C—H⋯S inter­action occurs. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds occur, leading to R 2 2(10) loops, and C—H⋯O and weak C—H⋯π inter­actions further consolidate the packing

(5Z)-5-(2-Methyl­benzyl­idene)-3-phenyl-2-thioxo-1,3-thia­zolidin-4-one

In the title compound, C17H13NOS2, the heterocyclic ring is oriented at a dihedral angle of 74.43 (5)° with respect to the anilinic benzene ring and at a dihedral angle of 17.31 (9)° with respect to phenyl ring. An intra­molecular C—H⋯S inter­action occurs, resulting in an S(6) ring. In the crystal, the packing is consolidated by C—H⋯π inter­actions and possible very weak aromatic π–π stacking [centroid–centroid separation = 4.025 (1) Å]

(5E)-5-(4-Hydr­oxy-3-methoxy­benzyl­idene)-2-thioxo-1,3-thia­zolidin-4-one methanol monosolvate

In the title compound, C11H9NO3S2·CH4O, the dihedral angle between the aromatic rings is 3.57 (16)° and intra­molecular O—H⋯O and C—H⋯S inter­actions occur. In the crystal, the thia­zolidin-4-one mol­ecules are linked by N—H⋯O hydrogen bonds, forming chains. The hydrogen-bond motifs lead to S(5), S(6) and R 3 3(8) ring motifs. There exist C=O⋯π inter­actions between the heterocyclic rings and π–π inter­actions between the heterocyclic and benzene rings at distances of 3.455 (2) and 3.602 (2) Å, respectively. The methanol solvent mol­ecule is disordered over two sets of sites in a 0.542 (9):0.458 (9) ratio

(5Z)-5-(2-Hydroxy­benzyl­idene)-2-thioxo-1,3-thia­zolidin-4-one methanol hemisolvate

In the title compound, C10H7NO2S2·0.5CH3OH, the dihedral angle between the aromatic rings is 11.43 (11)° and a short intra­molecular C—H⋯S contact occurs. The methanol solvent mol­ecule is equally disordered over two sets of sites. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds occur. The methanol solvent mol­ecule connects the dimers through O—H⋯S and O—H⋯O inter­molecular hydrogen bonds. Further stability is afforded by C—H⋯π and π–π inter­actions [centroid–centroid separation = 3.5948 (13) Å]

3-Benzyl-5-benzyl­idene-2-sulfanylidene-1,3-thia­zolidin-4-one

In the title mol­ecule, C17H13NOS2, the essentially planar thia­zole ring (r.m.s deviation 0.005 Å) forms dihedral angles of 16.85 (8)° and 75.02 (8)° with the phenyl rings. The dihedral angle between the two phenyl rings is 61.95 (9)°

Enzyme inhibition, antioxidant and antibacterial potential of vasicine isolated from Adhatoda vasica

Abstract: Vasicine (1) was isolated from the ethanolic extract of Adhatoda vasica Nees (Acanthaceae) and the structure was confirmed using spectroscopic techniques. Acetylcholine esterase, trypsin, DPPH inhibition potential and FRAP assay were carried out using in vitro models. The results showed 38.4 ± 1.2% and 37.4 ± 1.1% activity in acetylcholine and trypsin inhibition assays respectively. The compound (1) exhibited significant DPPH inhibition activity (70.4 ± 1.3%, IC 50 = 212.3 ± 1.9 µM). A dose dependant behavior of vasicine (1), was indicated in the FRAP assay. Antibacterial activity was checked according to agar well diffusion assay and results revealed that vasicine (1) showed moderate activity

Exhaust emission profiling of fatty acid methyl esters and NOx control studies using selective synthetic and natural additives

The present study was focused on the optimized biodiesel production using Moringa oleifera (M. oleifera) and rice bran oils, characterization, and comparative evaluation of the exhaust emission profile using artificial and natural additives resulting from synthesized biodiesel. Furthermore, various biodiesel blends (B10, B20, B50, and B100) of Moringa oleifera (M. oleifera) and rice bran oils were studied in a four-cylinder, direct injection engine at different engine speeds (1800–3000 rpm). The optimal yields (%) for both the M. oleifera and rice bran oil-based biodiesel were found to be 87 ± 2.0 and 93 ± 2.6%, respectively, using sodium methoxide as the catalyst. The optimized reaction parameters involved in the transesterification of the M. oleifera and rice bran oils were revealed to be catalyst concentration (1.25%), methanol-to-oil molar ratio (9:1), reaction temperature (60 °C), and reaction time (90 min). The fuel properties of the M. oleifera and rice bran oil-based biodiesel were found to be in compliance with ASTM D6751 and EN 14214. The exhaust emission levels of the synthesized biodiesel and its blends with conventional diesel showed a significant reduction in the particulate matter and carbon monoxide levels comparative to the fossil fuel-based diesel combustion, whereas an increasing trend was observed in case of the oxides of nitrogen (NOx) emission. The results of the engine performance test indicated that the brake power in all of the samples had approximately similar values for each load and the enriched blends showed a distinct improvement in brake-specific fuel consumption. The effect of antioxidants on the NOx emission levels resulting from the combustion of the biodiesel and its blends showed that the synthetic additives (butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT), t-butyl hydroquinone (TBHQ), and propyl gallate (PG)) were more effective than the natural methanolic antioxidant extracts (extract of P. pinnata (EPPL), extract of A. lebbeck (EPPL), extract of P. guajava (EPG), and extract of M. azedarcah (EMA) for reduction in the NOx emission level

3-Acetyl-1-(3-chloro­phen­yl)thio­urea

In the title compound, C9H9ClN2OS, the 3-chloro­phenyl and acetyl­thio­urea fragments are oriented at a dihedral angle of 62.68 (5)°. An intra­molecular N—H⋯O hydrogen bond generates an S(6) ring motif. Mol­ecules are linked into dimers via a cyclic R 2 2(8) motif of N—H⋯S hydrogen bonds. These dimers are further connected through C—H⋯S inter­actions, completing an R 2 2(12) motif, into chains along [010]