Antioxidant and antibacterial activities of Hibiscus Rosa-sinensis Linn flower extracts.

Antioxidant and antibacterial potential of different solvent extracts of locally grown Hibiscus rosa-sinensis Linn was evaluated. The antioxidant activity was assessed by estimation of total flavonoids contents, total phenolic contents, DPPH free radical scavenging activity and percentage inhibition of linoleic acid oxidation capacity. Agar disc diffusion method was used to assess antibacterial potential of crude extract of H. rosa-sinensis. The yield of the crude extracts (23.21 ± 3.67 and 18.36 ± 2.98% in 80% methanol and ethanol solvents was calculated, respectively. Methanol and ethanol extract of H. rosa-sinensis showed total phenolics 61.45 ± 3.23 and 59.31 ± 4.31 mg/100g as gallic acid equivalent, total flavonoids 53.28 ± 1.93 and 32.25±1.21 mg/100g as catechine equivalent, DPPH free radical scavenging activity 75.46±4.67 and 64.98 ± 2.11% and inhibition of linoleic acid oxidation potential 75.8 ±3.22 and 61.6 ± 2.01% respectively, was measured. Antibacterial study against three human pathogens such as staphlococus sp. Bacillus sp. and Escherichia coli showed growth inhibitory effect in the range of 12.75 ± 1.17 to 16.75 ± 2.10 mm. These results showed H. rosa-sinensis indigenous to Kallar Kahar and its allied areas bear promising medicinal values and could be used for developing herbal medicines to target oxidative stress and infectious diseases.

Studies on molecular interactions of some sweeteners in water by volumetric and ultrasonic velocity measurements at T=(20.0-45.0°C).

Densities and ultrasonic velocity values for aqueous solutions of two sweeteners viz., maltose monohydrate and acesulfame-K have been measured as a function of concentration at 20.0-45.0°C and atmospheric pressure. Solutions of acesulfame-K were treated as electrolyte, while maltose was considered as non-electrolyte. The apparent molar and specific volumes, their isentropic apparent molar and specific compressibilities, as well as their compressibility hydration numbers have been calculated and reported. Negative deviations from Debye-Huckel limiting law of apparent molar volume for acesulfame-K was obtained at given temperatures and can be used as a direct measure of the ion-ion and ion-solvent interactions. Furthermore, apparent specific volumes of the solutes were calculated and it was found that these values of the investigated solutes lie on the borderline between the values reported for sweet substances. The partial molar expansibility, its second derivative values, (∂(2)V(0)/∂T(2)) and thermal expansion coefficient have been estimated.

Efficient synthesis of 2-amino-6-arylbenzothiazoles via Pd(0) Suzuki cross coupling reactions: potent urease enzyme inhibition and nitric oxide scavenging activities of the products.

In general, benzothiazole derivatives have attracted great interest due to thier pharmaceutical and biological importance. New 2-amino-6-arylbenzothiazoles were synthesized in moderate to excellent yields via Suzuki cross coupling reactions using various aryl boronic acids and aryl boronic acid pinacol esters and the antiurease and nitric oxide (NO) scavenging activity of the products were also examined. The most active compound concerning urease enzyme inhibition was 6-phenylbenzo[d]thiazole-2-amine 3e, with an IC50 value of 26.35 µg/mL. Compound 3c, 6-(4-methoxyphenyl) benzo[d]thiazole-2-amine, exhibited the highest nitric oxide percentage scavenging at 100 µg/mL.

6-Bromo-1-methyl-4-[2-(1-phenyl-ethyl-idene)hydrazinyl-idene]-3,4-dihydro-1H-2λ(6),1-benzothia-zine-2,2-dione.

In the title compound, C(17)H(16)BrN(3)O(2)S, the dihedral angle between the aromatic rings is 1.24 (15)° and the C=N-N=C torsion angle is 167.7 (3)°. The conformation of the thia-zine ring is an envelope, with the S atom displaced by 0.805 (3) Šfrom the mean plane of the other five atoms (r.m.s. deviation = 0.027 Å). In the crystal, C-H⋯O inter-actions link the mol-ecules into C(10) [010] chains. A weak C-H⋯π inter-action is also observed.

In vitro antimicrobial, antioxidant, cytotoxicity and GC-MS analysis of Mazus goodenifolius.

The antimicrobial, antioxidant and cytotoxic properties of Mazus goodenifolius (Hornem.) Pennell essential oil, methanol extract and some solvent-extracted subfractions of the latter were appraised. A qualitative, quantitative analysis of the classes of phytochemicals in the various fractions and GC-MS analysis of the essential oil was carried out. The activity of the plant extract and various subfractions against selected bacterial (Pasturella multocida, Escherichia coli, Bacillus subtilis and Staphylococcus aureus) and fungal strains (Aspergillus niger, Aspergillus flavus, Alternaria alternata and Rhizopus solani) was evaluated. The antioxidant activity was assayed using the DPPH radical scavenging and % inhibition of linoleic acid peroxidation tests. In the DPPH radical scavenging test the IC50 values ranged from 7.21 to 91.79 µg/mL, and in the latter the range of % peroxidation inhibition was 35.42-93.48%. Protective effects of the absolute methanol extract, which had the highest content of phenolics and flavonoids, against H2O2 induced oxidative damage in plasmid pBR322 DNA was also evaluated, and it was found to offer some protection at the highest tested dose (1,000 µg/mL). Finally the cytotoxicity of the plant extract, fractions and essential oil was analyzed by examining haemolytic activity against human blood erythrocytes (RBCs), whereby the % lysis of RBCs was found to be in the range of 1.65 to 4.01%.

2-{[2-(1-Methyl-2,2-dioxo-3,4-dihydro-1H-2λ(6),1-benzothia-zin-4-yl-idene)hydrazin-1-yl-idene]meth-yl}phenol.

In the title compound, C(16)H(15)N(3)O(3)S, the dihedral angle between the aromatic rings is 8.18 (11)° and the C=N-N=C torsion angle is 178.59 (14)°. The conformation of the thia-zine ring is an envelope, with the S atom displaced by 0.8157 (18) Šfrom the mean plane of the other five atoms (r.m.s. deviation = 0.045 Å). An intra-molecular O-H⋯N hydrogen bond closes an S(6) ring. In the crystal, weak C-H⋯O inter-actions link the mol-ecules, with all three O atoms acting as acceptors.

1-Ethyl-4-[1-(1-phenyl-ethyl-idene)hydrazin-2-yl-idene]-3,4-dihydro-1H-2λ(6),1-benzothia-zine-2,2-dione.

In the title compound, C(18)H(19)N(3)O(2)S, the thia-zine ring adopts an envelope conformation, with the S atom displaced by 0.732 (1) Šfrom the other atoms of the ring. The phenyl ring is oriented at a dihedral angle of 79.33 (7)° with respect to the fused benzene ring. The conformations about the two double bonds in the R(2)C=N-N=C(CH(3))Ar grouping are Z and E, respectively. In the crystal, inversion dimers linked by pairs of C-H⋯O inter-actions generate R(2) (2)(8) and R(2) (2)(12) loops, as parts of infinite chains along the a-axis direction.

3,4-Dimethyl-2-(2-oxo-2-phenyl-eth-yl)-2H,4H-pyrazolo-[4,3-c][1,2]benzothia-zine-5,5-dione.

In the title mol-ecule, C(19)H(17)N(3)O(3)S, the heterocyclic thia-zine ring adopts a half-chair conformation with the S and N atoms displaced by 0.530 (5) and 0.229 (6) Å, respectively, on opposite sides of the mean plane formed by the remaining ring atoms. The ethanone group lies at an angle of 3.8 (3)° with respect to the benzene ring, which lies almost perendicular to the pyrazole ring, with a dihedral between the two planes of 89.22 (11)°. Weak inter-molecular C-H⋯O hydrogen-bonding inter-actions are present.

Prediction of robustly large molecular second-order nonlinear optical properties of terpyridine-substituted hexamolybdates: structural modelling towards a rational entry to NLO materials.

We have explored an innovative, versatile, and novel molecular hybrid containing polyoxometalate (POM) cluster linked with terpyridine ligand via pi-bridged donor-acceptor (D-A) configuration. The dipole polarizabilities, density of states, and second-order nonlinear optical (NLO) properties of terpyridine-substituted hexamolybdates have been investigated by using time-dependent density functional response theory (TDDFT). This class of organic-inorganic hybrid compounds possesses a robustly large molecular second-order NLO response, especially [Mo(6)O(18)(N(4)C(25)H(16)I(2))](2-) (system 5) and [Mo(6)O(17)(N(4)C(25)H(16)(CN)(2))(N(4)C(25)H(16)(CN)(2))](2-) (system 10) with the static second-order polarizability (beta(vec)) computed to be 1209.25x10(-30)esu and 1622.67x10(-30)esu respectively. Thus, these systems have the possibility to be excellent second-order nonlinear optical materials. Analysis of the major contributions to the beta(vec) value suggests that the charge transfer (CT) from POM-cluster to terpyridine ligand (D-A) along the z-axis plays the key role in the NLO response, POM-cluster (hexamolybdates) acts as a donor (D) whereas terpyridine ligand acts as an acceptor (A) in all the studied systems. The computed beta(vec) values increase by the incorporation of electron acceptors (halogen=F, Cl, Br and I) at the terminus of terpyridine ligand. Furthermore, substitution of trifluoromethoxy (-OCF(3)), trifluoromethyl (-CF(3)), and cyanide (-CN) at the end of terpyridine ligand respectively enhances the optical nonlinearity. Orbital analysis shows that the degree of CT between POM and terpyridine segment was increased in 2D and organometallic/POM hybrid systems. The present investigation provides important and thought provoking insight into the robustly large NLO properties of terpyridine-substituted hexamolybdates.

2-(2-Oxo-2-phenyl-ethyl)-1,2-benziso-thia-zol-3(2H)-one 1,1-dioxide.

In the title compound, C(15)H(11)NO(4)S, the benzothia-zole unit is essentially planar [maximum deviation = 0.0644 (14) Šfor the N atom] and forms a dihedral angle 54.43 (6)° with the phenyl ring. In the crystal structure, weak bifurcated C-H⋯O hydrogen bonds involving the carbonyl O atoms as acceptors result in R(2) (2)(7) ring motifs.

2-[2-(3-Chloro-phen-yl)-2-oxoeth-yl]-1,2-benzisothia-zol-3(2H)-one 1,1-dioxide.

In the title compound, C(15)H(10)ClNO(4)S, the benzothia-zole ring system is essentially planar [maximum deviation = 0.0382 (13) Šfor the N atom] and forms a dihedral angle of 74.43 (6)° with the chloro-substituted benzene ring. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds form R(2) (2)(10) and R(2) (2)(16) ring motifs.