Synthesis, antibacterial activities and phospholipid membrane interactions of novel dialkyl 2,2’-disulfanediyldibenzoates

A series of dialkyl 2,2’-disulfanediyldibenzoates with alkyl chain length C8 to C12 were synthesized and characterized by spectral studies. The structure of compound 3 was also confirmed by X-ray crystallography. The compounds were found to possess good antibacterial activity, especially with respect to Gram positive bacteria, and the activity was found to increase with concomitant increase in chain length. Binding studies of compound 3 with the synthetic phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) showed that the compound interacts with biological membrane mainly via hydrophobic interactions

Quantification of Sugars in Soft Drinks and Fruit Juices by Density, Refractometry, Infrared Spectroscopy and Statistical Methods

The amount of sugar in soft drinks and fruit juices has been quantified by density, refractometric and infrared spectroscopic methods. Density and refractometric methods can be used to obtain only the total amount of sugar. However, infrared spectroscopy distinguishes itself as a fast and reliable method for quantitative analysis. Fourier-transformedspectroscopy in combination with a mathematical treatment of the spectra of samples allows the amount of different sugars such as glucose, fructose and sucrose to be determined. Keywords: Sugar, Density, Refractrometry, Mid-FTIR, Partial least squares South African Journal of Chemistry Vol.57 2004: 24-2

N,N′-(2,2′-Dithiodi-o-phenyl­ene)bis­(furan-2-carboxamide)

The reaction of 2,2′-dithio­bis(benzenamine) with furan-2-carbonyl chloride produced the bis-amide title compound, C22H16N2O4S2, which, in the crystal, formed a helix; the structure consists of two planar furanoylbenzenamines related by an improper rotation of 96.3° about the S—S bond. The N-furanoylbenzenamine units are planar (maximum deviations = 0.316 and 0.132 Å). Each electron-deficient acyl­furan stacks (centroid–centroid separations of the two pairs of π–π stacked aromatic rings are 3.918 and 3.953 Å) with the electron-rich benzenamine of the other N-furan­oyl­benzenamine unit, leading to a spiral structure. The conformation is stabilized by two bifurcated intramolecular N—H⋯(O,S) interactions

Morphology, biological and chemical profiling of three Polyscias species, endemic to Mauritius

The aim of the study is to screen the morphological, anatomical, biological, and chemical profiles of the leave extracts of endemic Polyscias species namely P. dichroostachya (PD), P. gracilis (PG), and P. mauritiana (PM) from Mauritius. The morphology and anatomy of the leaves were studied using a microscope. Phytochemical screening of extracts using LC-MS/MS was carried out by ionization in both positive and negative modes. The leaves are pinnately compound, hypostomatic, dorsiventral, with a prominent mid vein with secretion cavities, and they can be distinguished by their midrib shape and anatomy. From the molecular mass and fragmentation data, 31 terpenoid saponins, 19 flavonoids, 17 acids, 7 terpenes, and 10 miscellaneous compounds including pyrrolidines and acetylenes in different extracts (hexane, ethanol, and aqueous) were identified. Extracts from the three species using DPPH radical scavenging activity exhibited good to moderate antioxidant activities with IC50 values in the range of 2.1-70.8 mg/ml and the ethanolic extract of PD showing the highest activity. Aqueous extracts of PG and PM potently inhibited alpha-glucosidase with IC50 values of 0.50 and 2.62 mg/ml. The different leaf extracts exhibited moderate activity against a panel of gram-positive and gram-negative bacteria. This is probably the first report on the extensive chemical profiling and morphology of these endemic Polysias spp. from Mauritius and the results indicate that these leaf extracts have beneficial health properties and are thus worth exploiting further

Biological activity of synthesized 5-{1-[(4-chlorophenyl)sulfonyl]piperidin-4- yl}-2-mercapto-1,3,4-oxadiazole derivatives demonstrated by in silico and BSA binding studies

We synthesized a series of compounds bearing pharmacologically important 1,3,4-oxadiazole and piperidine moieties. Spectral data analysis by 1 H-NMR, 13C-NMR, IR and EI-MS was used to elucidate the structures of the synthesized molecules. Docking studies explained the different types of interaction of the compounds with amino acids, while bovine serum albumin (BSA) binding interactions showed their pharmacological effectiveness. Antibacterial screening of these compounds demonstrated moderate to strong activity against Salmonella typhi and Bacillus subtilis but only weak to moderate activity against the other three bacterial strains tested. Seven compounds were the most active members as acetyl cholinesterase inhibitors. All the compounds presented displayed strong inhibitory activity against urease. Compounds 7l, 7m, 7n, 7o, 7p, 7r, 7u, 7v, 7x and 7v were highly active, with respective IC50 values of 2.14±0.003, 0.63±0.001, 2.17±0.006, 1.13±0.003, 1.21±0.005, 6.28±0.003, 2.39±0.005, 2.15±0.002, 2.26±0.003 and 2.14±0.002 µM, compared to thiourea, used as the reference standard (IC50 = 21.25±0.15 µM). These new urease inhibitors could replace existing drugs after their evaluation in comprehensive in vivo studies

New Lobane and Cembrane Diterpenes from Two Comorian Soft Corals

Preliminary biological investigation of a collection of Comorian soft corals resulted in the selection of two specimens, one of Sarcophyton and the other of Lobophytum, on the basis of their toxicity on larvae of the brine shrimp (Artemia salina) and inhibition of acetylcholinesterase, respectively. Bioassay-guided fractionations provided a known antitumor promoter cembrane diterpenoid, (+)-sarcophytol-A (1), along with a new lobane diterpenoid, carbomethoxyfuscol (2), from Sarcophyton sp., and a new cembranoid, crassumolide E (3), from Lobophytum sp. The structures of compounds 1–3 were determined by spectroscopic analysis and by comparison of the spectral data with previously reported values. The cembranoid 3 was found to exhibit a moderate inhibitory effect on acetylcholinesterase

Antibacterial & Catalytic Activities of 2,2\'-Dithio (2-Hydroxyphenyl) Benzamide (Dnbh) and its Ruthenium Metal Complexes.

This paper describes the in vitro evaluation of antibacterial activity of DNBH and its ruthenium complexes. All the synthesized compounds exhibited antibacterial activity against the Gram-positive bacteria namely Staphylococcus aureus at a conc of 100-25 mg/ml and Gram-negative bacteria such as Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa at a conc of 1µg/ml. All the metal complexes display catalytic activities towards oxidation of primary alcohols in the presence of N-methylmorpholine-N-Oxide (NMO) as co-oxidant. (Af. J. of Science and Technology: 2002 3(2): 52-55

Spectroscopic and molecular docking investigation on the interaction of novel radical scavengers N-acyl monomeric and gemini 3, 4-dihydroxy-L-phenylalanine (L-DOPA) surfactants with bovine serum albumin

L-DOPA (3,4-dihydroxyphenyl-L-alanine) is a drug of choice for Parkinson’s disease (PD). However, its clinical application is often hindered by limitations such as poor solubility and bioavailability. Four single-chained N-acyl L-DOPA with varying chain lengths (C10-C16) and three dissymmetric gemini surfactants have been synthesized with a view of overcoming these associated problems. Selected physicochemical properties which included critical micelle concentration (CMC), surface tension, aggregation number, and biochemical properties such as radical scavenging and bovine serum albumin (BSA) binding, have been evaluated. The effect of the hydrophobic chain length as well as unsaturation on the physicochemical, radical scavenging abilities, and binding properties were explored. Contrarily to the monomeric compounds, the CMC of the gemini surfactants increased with the increasing number of carbon atoms, and the presence of unsaturation in the alkyl chain, which contributed to the steric hindrance, led to the perturbation of micelle formation. The aggregation number was found to increase with increasing chain length for the monomeric surfactants, while it decreased with an increase in chain length and unsaturation within the gemini series. The monomeric C12 displayed enhanced radical scavenging abilities, the optimum binding properties with BSA among all the N-acyl L-DOPA derivatives, and also showed better interfacial properties. The radical scavenging abilities and binding affinity of the gemini surfactants were lower compared to the monomeric analogues, while the presence of the double bond in the alkyl chain was found to promote the radical scavenging abilities and binding properties. BSA binding interaction studies showed that N-acyl L-DOPA surfactants quenched the BSA intrinsic fluorescence by a combined static and dynamic mechanism and tended to bind to sub-domains IIA (site I) and IIIA (site II) of BSA. The molecular docking showed similar results, whereby the monomeric surfactants had more affinity towards site I while the gemini surfactants preferred site II. The findings from UV–vis absorption, synchronous, and FT-IR studies corroborated and confirmed the structural conformation changes of BSA resulting from its binding with N-acyl L-DOPA derivatives. This study showed that steric hindrance and rigidity alter aggregation formation and reduce binding ability

Phytochemical screening and antioxidant properties of phyllanthus emblica from Mauritius

The phytochemical screening showed the presence of phenols, flavonoids, non-flavonoid, tannins, alkaloids, saponins, and phytosterols in the different extracts (diethyl ether, ethyl acetate, butanol, and aqueous extracts) of dried fruits of Phyllanthus emblica (Amla). Low-molecular-weight aliphatic acids, phenolic acids, methyl/ethyl gallate, phytosterols, and tannins were identified in the fruits using UPLC-MS/MS. The scavenging activity of Amla was assessed using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis-3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assays. The ethyl acetate extract showed the highest total phenolic and flavonoid contents, which was also found to have the highest antioxidant potential with SC50, 1.33 ± 0.77 and 4.13 ± 0.99 μg/mL for the DPPH and ABTS assays, respectively. The high phenolic, flavonoid, and the antioxidant activity of the extracts indicated that the local Amla could be exploited as an antioxidant supplement

Three anilides of 2,2′-thiodibenzoic acid

The structures ofN,N′-bis(2-methylphenyl)-2,2′-thiodibenzamide, C28H24N2O2S, (Ia),N,N′-bis(2-ethylphenyl)-2,2′-thiodibenzamide, C30H28N2O2S, (Ib), andN,N′-bis(2-bromophenyl)-2,2′-thiodibenzamide, C26H18Br2N2O2S, (Ic), are compared with each other. For the 19 atoms of the consistent thiodibenzamide core, the r.m.s. deviations of the molecules in pairs are 0.29, 0.90 and 0.80 Å for (Ia)/(Ib), (Ia)/(Ic) and (Ib)/(Ic), respectively. The conformations of the central parts of molecules (Ia) and (Ib) are similar due to an intramolecular N—H...O hydrogen-bonding interaction. The molecules of (Ia) are further linked into infinite chains along thecaxis by intermolecular N—H...O interactions, whereas the molecules of (Ib) are linked into chains alongbby an intermolecular N—H...π contact. The conformation of (Ic) is quite different from those of (Ia) and (Ib), since there is no intramolecular N—H...O hydrogen bond, but instead there is a possible intramolecular N—H...Br hydrogen bond. The molecules are linked into chains alongcby intermolecular N—H...O hydrogen bonds.</jats:p