Photophysical Properties of Linear, Net-structured and Branched Polybenzimidazoles.

Polybenzimidazoles with three different network structures are synthesized by condensation polymerization between the conventional monomer 3,3'-Diaminobenzidine and three different acid monomers. The synthesised polymer networks are characterized using several characterization techniques such as FT-IR, powder XRD, HR-SEM and TG-DTA analyses. The polybenzimidazoles are amorphous in nature with excellent thermal stability up to 450 ºC. The photophysical properties of polybenzimidazoles are studied using UV-visible absorption and Emission spectral techniques. Further, the excited state photoluminescence decay time measurement shows a functional group dependant decay behaviour. All the three polymers display narrow optical band gap energy and could be applied as a material for solar energy conversion and semiconductors.

Effect of steaming, blanching, and high temperature/high pressure processing on the amino Acid contents of commonly consumed korean vegetables and pulses.

In the present report, the effects of blanching, steaming, and high temperature/high pressure processing (HTHP) on the amino acid contents of commonly consumed Korean root vegetables, leaf vegetables, and pulses were evaluated using an Automatic Amino Acid Analyzer. The total amino acid content of the samples tested was between 3.38 g/100 g dry weight (DW) and 21.32 g/100 g DW in raw vegetables and between 29.36 g/100 g DW and 30.55 g/100 g DW in raw pulses. With HTHP, we observed significant decreases in the lysine and arginine contents of vegetables and the lysine, arginine, and cysteine contents of pulses. Moreover, the amino acid contents of blanched vegetables and steamed pulses were more similar than the amino acid contents of the HTHP vegetables and HTHP pulses. Interestingly, lysine, arginine, and cysteine were more sensitive to HTHP than the other amino acids. Partial Least Squares-Discriminate Analyses were also performed to discriminate the clusters and patterns of amino acids.

An eco-friendly and water mediated product selective synthesis of 2-aminopyrimidines and their in vitro anti-bacterial evaluation.

A greener water mediated protocol for the efficient synthesis of a library of 2-amino-6-styryl pyrimidines (4) and their dihydro analogues (3) has been reported. Most of the saturated compounds (3) rather than their unsaturated analogues (4) showed better anti-bacterial (in vitro) activity against three human pathogens viz. Staphylococcus aureus, Klebsiella pneumonia and Escherichia coli. In particular, three of them (3 b, 3 i &3 k) exhibited high inhibition against the growth of all the three pathogens comparable with that of the reference drug, tetracycline.

Evaluation of sugar content and composition in commonly consumed Korean vegetables, fruits, cereals, seed plants, and leaves by HPLC-ELSD.

In the present investigation, evaluation of sugars viz. fructose, galactose, glucose, sucrose, lactose, maltose, and raffinose in commonly consumed raw Korean vegetables, fruits, cereals, seed plants, and leaves has been analyzed using high-performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD). Of the 58 samples analyzed, Onion showed the highest content of fructose (27.74g/100g) and glucose (31.80g/100g) and Chestnuts showed the highest content of sucrose (21.82g/100g). On the other hand, Glutinous sorghum (polished grain), Green tea leaves, and Paddy rice (well-polished rice) showed the lowest content of fructose (0.20g/100g), glucose (0.68g/100g) and sucrose (0.23g/100g), respectively. Glutinous barley (Hopimbori-whole grain) and Green tea leaves showed 0.17g/100g and 0.57g/100g of galactose and lactose respectively. Glutinous barley (Seodunchalbori-polished grain) and Black soybeans (Cheongjaho, dried) showed the highest content of maltose (0.51g/100g) and raffinose (1.82g/100g), respectively. In few samples, galactose, maltose, lactose, and raffinose were detected in trace quantities. A partial least squares discriminant analysis (PLS-DA) was also performed to discriminate the analyzed samples.

Evaluation of γ-oryzanol content and composition from the grains of pigmented rice-germplasms by LC-DAD-ESI/MS.

BACKGROUND: Rice is the staple food and one of the world's three major grain crops. Rice contains more than 100 bioactive substances including phytic acid, isovitexin, γ-oryzanol, phytosterols, octacosanol, squalene, γ-aminobutyric acid (GABA), tocopherol, tocotrienol derivatives, etc. Out of them, γ-oryzanol is known to have important biological profile such as anti-oxidants, inhibitor of cholesterol oxidation, reduce serum cholesterol levels in animals, effective in the treatment of inflammatory diseases, inhibit tumor growth, reduce blood pressure and promotes food storage stability when used as a food additive, etc. Hence in the present investigation, we aimed to evaluate the content and composition of γ-oryzanol from pigmented rice germplasms using a liquid chromatography with diode array detection and electrospray ionization-mass spectrometry (LC-DAD-ESI/MS). FINDINGS: In the present study, 33 exotic pigmented rice accessions (red, white and purple) have been evaluated. Among them, the contents of γ-oryzanol varied from 3.5 to 21.0 mg/100 g with a mean of 11.2 mg/100 g. A total of ten components of γ-oryzanol including Δ7-stigmastenyl ferulate were identified of which, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate, campesteryl ferulate and sitosteryl ferulate were identified as the major components. The mean proportions of steryl ferulates were in the descending order of 24-methylenecycloartanyl ferulate > cycloartenyl ferulate > campesteryl ferulate > sitosteryl ferulate > Δ7-campestenyl ferulate > campestanyl ferulate > sitostanyl ferulate > Δ7-stigmastenyl ferulate > stigamsteryl ferulate > Δ7-sitostenyl ferulate. Almost 11 accessions (33%) showed higher content than the control rice Chucheongbyeo and higher proportions ranged from 10 to 15 mg/100 g. Interestingly, the red rice accession Liberian Coll. B11/B-11 (21.0 mg/100 g) showed higher content γ-oryzanol than control rice Jeokjinjubyeo (19.1 mg/100 g) and the purple rice accession Padi Adong Dumarat, Mardi No.4376 (20.3 mg/100 g) showed a similar content with control rice Heugjinjubyeo (21.4 mg/100 g). CONCLUSIONS: Most of analyzed rice accessions were found to possess higher contents of γ-oryzanol than the control rice, Chucheongbyeo. In particular, the red accessions showed highest content than the white and purpleaccessions. The content and composition of γ-oryzanol in 33 exotic pigmented rice accessions have been evaluated and compared significantly by the present investigation.

A facile, rapid, one-pot regio/stereoselective synthesis of 2-iminothiazolidin-4-ones under solvent/scavenger-free conditions.

A rapid and efficient one pot solvent/scavenger-free protocol for the synthesis of 2-iminothiazolidin-4-ones has been developed. Interestingly, the regio/stereoselective synthesis affords the regioisomeric (Z)-3-alkyl/aryl-2-(2-phenylcyclohex-2-enylimino)thiazolidin-4-one as the sole product in good yield. The selectivities observed have been rationalized based on the relative magnitude of the allylic strains developed during the course of the reaction. This is the first report wherein the impact of allylic strains in directing the regiocyclization has been noted.

4-Benzyl-8-phenyl-1-thia-4-aza-spiro-[4.5]decan-3-one.

In the title compound, C(21)H(23)NOS, the thia-zolidine ring adopts a twist conformation about one of its C-S bonds, while the cyclo-hexane ring has a chair conformation. The S and N atoms attached to the spiro C atom are in axial and equatorial orientations, respectively. The thia-zolidine ring forms dihedral angles of 86.24 (14) and 31.82 (15)° with the directly attached and remote terminal benzene rings, respectively. The dihedral angle between the two terminal benzene rings is 86.74 (14)°. In the crystal, the only significant directional inter-action is a weak C-H⋯π bond, which generates [010] chains.

3-Benzyl-2-phenyl-1,3-thia-zolidin-4-one.

In the title compound, C(16)H(15)NOS, the thia-zolidine ring, which is essentially planar [maximum deviation = 0.071 (2) Å], makes dihedral angles of 88.01 (8) and 87.21 (8)° with the terminal phenyl rings. The dihedral angle between the phenyl rings is 49.45 (5)°. In the crystal, mol-ecules are linked by a weak inter-molecular C-H⋯O hydrogen bond, forming a supra-molecular chain along the b axis. Furthermore, the crystal packing is stabilized by a weak C-H⋯π inter-action.

3-Benzyl-2-(furan-2-yl)-1,3-thia-zolidin-4-one.

In the title compound, C(14)H(13)NO(2)S, the thia-zolidine ring is approximately planar with a maximum deviation of 0.112 (1) Å. The furan ring is disordered over two orientations, with an occupancy ratio of 0.901 (5):0.099 (5). The central thia-zolidine ring makes dihedral angles of 85.43 (8), 87.50 (11) and 87.9 (9)° with the phenyl ring and the major and minor components of the disordered furan ring, respectively. In the crystal, mol-ecules are connected by weak inter-molecular C-H⋯O hydrogen bonds, forming supra-molecular chains parallel to the b axis.

(E)-1-(1-Benzyl-5-methyl-1H-1,2,3-triazol-4-yl)-3-(4-fluoro-phen-yl)prop-2-en-1-one.

The asymmetric unit of the title compound, C(19)H(16)FN(3)O, contains two crystallographically independent mol-ecules. The triazole rings in both mol-ecules are essentially planar with maximum deviations of 0.002 (1) and 0.001 (1) Å. The dihedral angles between the benzene and fluorophenyl rings are 79.36 (9) and 89.40 (10)° in the two molecules. In the crystal, the two independent mol-ecules are linked by C-H⋯N hydrogen bonds, forming dimers. Furthermore, the crystal structure is stabilized by C-H⋯π inter-actions.

(E)-1-(1-Benzyl-5-methyl-1H-1,2,3-triazol-4-yl)-3-phenyl-prop-2-en-1-one.

The asymmetric unit of the title compound, C(19)H(17)N(3)O, contains two independent mol-ecules. In one mol-ecule, the essentially planar triazole ring [maximum deviation = 0.003 (2) Å] forms dihedral angles of 5.57 (12) and 87.51 (12)° with the two phenyl rings, while in the other mol-ecule [maximum deviation in triazole ring = 0.001 (2) Å] these angles are 1.55 (10) and 82.73 (11)°. The dihedral angles between the two phenyl rings in the two mol-ecules are 87.77 (13) and 81.22 (11)°. In the crystal, the independent mol-ecules are connected via a weak C-H⋯N hydrogen bond, forming dimers. Further stabilization is provided by weak C-H⋯π inter-actions.

Efficient synthesis and in vitro antitubercular activity of 1,2,3-triazoles as inhibitors of Mycobacterium tuberculosis.

Efficient and rapid synthesis of 1,2,3-triazole derivatives has been achieved via Huisgen's 1,3-dipolar cycloaddition between alkyl/arylazides and diethyl/dimethyl acetylenedicarboxylate in excellent yields under solvent-free conditions. The environmentally friendly solvent-free protocol overcomes the limitations associated with the prevailing time-consuming solution phase protocols and affords the triazoles just in 1-3 min. In vitro antitubercular activity of these triazoles was screened against Mycobacterium tuberculosis H(37)Rv strain. Four of the compounds showed MIC in the range of 1.56-3.13 µg/mL proving their potential activity.