Synthesis, in vitro and computational studies of 1,4-disubstituted 1,2,3-triazoles as potential α-glucosidase inhibitors.

1,4-Disubstituted-1,2,3-triazoles were synthesized by Cu(I) catalyzed click reaction, where the azides, with electron donating and electron withdrawing groups acted as 1,3-dipoles and 1-ethynyl-1-cyclohexanol served as the terminal alkyne. These synthesized triazoles were subjected to enzymatic assay which showed promising activity against α-glucosidase; 1-(2-cyano-4-nitrophenyl)-4-(1-hydroxycyclohexyl)-1H-1,2,3-triazole 3m being the most active members of the library. Molecular docking studies of these triazoles with the homology-modeled α-glucosidase protein were also performed to delineate ligand-protein interactions at molecular level which suggested that Phe157, Arg312 and His279 are the major interacting residues in the biding site of the protein and may have a significant role in the inhibition of enzyme's function.

Parvisides A and B, new glucosides from Galinsoga parviflora.

Phytochemical investigations of the n-butanol soluble sub-fraction of the methanolic extract of Galinsoga parviflora Cav. has led to the isolation of two new glucosides named as parvisides A (1) and B (2). Their structures have been assigned on the basis of their spectral analysis including 1D and 2D NMR techniques.

Loasins A and B, new flavonoids from Eremostachys loasifolia.

Loasins A (1) and B (2), new flavonoids, have been isolated from the ethyl acetate soluble sub-fraction of the ethanolic extract of Eremostachys loasifolia along with apuleisin (3) and apuleidin (4), isolated for the first time from this species. Their structures were assigned on the basis of their spectral data including 1D and 2D NMR.

Two new biisoflavonoids from the roots of Daphne oleoides.

Phytochemical investigation of the ethyl acetate soluble fraction of the methanol soluble extract of the roots of Daphne oleoides resulted in isolation and identification of two new isomeric biisoflavonoids characterized as 8,8"-bi-6-hydroxyorobol (1) and 8,8"-bi-6, 2'-dihydroxygenistein (2). The structures of these compounds were established by analysis of their 1D and 2D NMR and HRMS data.

Ophiamides A-B, new potent urease inhibitory sphingolipids from Heliotropium ophioglossum.

Ophiamides A (1) and B (2), two new sphingolipids have been isolated from the n-hexane subfraction of the MeOH extract of the whole plant of Heliotropium ophioglossum along with glycerol monopalmitate (3) and β-sitosterol 3-O-β-D: -glucoside (4) reported for the first time from this species. Their structures were elucidated by spectroscopic techniques including MS and 2D-NMR spectroscopy. Both the compounds 1 and 2 showed potent inhibitory activity against the enzyme urease.

[4,4'-(Ethane-1,2-diyldinitrilo)-bis-(pent-2-en-2-olato)]copper(II) 0.25-hydrate.

In the title compound, [Cu(C(12)H(18)N(2)O(2))]·0.25H(2)O, the coordination of the O,N,N',O'-tetra-dentate ligand results in a cis-CuN(2)O(2) square-planar geometry for the metal ion and the presence of two six-membered and one five-membered chelate rings. The complete complex mol-ecule is close to planar (r.

{5-Chloro-2-[(4-chloro-benzyl-idene)-amino]-phen-yl}(phen-yl)methanone.

In the title compound, C(20)H(13)Cl(2)NO, the C=N bond adopts an E conformation. The chloro-substituted rings form a dihedral angle of 11.99 (9)° with each other and form dihedral angles of 74.

Bioactive phenolic amides from Celtis africana.

Nine compounds have been isolated for the first time from Celtis africana, namely trans-N-coumaroyltyramine (1), trans-N-feruloyltyramine (2), trans-N-caffeoyltyramine (3), lauric acid (4), oleic acid (5), palmitic acid (6), lupeol (7), β-sitosterol (8) and oleanolic acid (9), respectively. Their structures have been elucidated by different spectroscopic techniques. The isolated compounds were screened for their antioxidant, anti-inflammatory and acetylcholinestrease enzyme inhibitory activities.

New aromatic esters from Galinsoga parviflora.

Galinosoates A-C (1-3), new aromatic esters, have been isolated from the n-hexane soluble fraction of Galinsoga parviflora. Their structures were assigned from the spectral data including IR, HR-EI-MS, 1D and 2D NMR.

N'-[(Z)-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)methyl-idene]-2-hy-droxy-benzohydrazide.

In the title compound, C(19)H(18)N(4)O(3), the pyrazole ring is oriented at dihedral angles of 41.12 (7) and 12.25 (10)°, respectively, with respect to the planes of the phenyl and benzene rings.

Biologically active bergenin derivatives from Bergenia stracheyi.

New bergenin derivatives, bergecins A and B (1 and 2, resp.), have been isolated from the AcOEt-soluble fraction of Bergenia stracheyi, along with bergenin (3), and their structures were elucidated on the basis of (1) H- and (13) C-NMR spectra, and by COSY, HMQC, and HMBC experiments. Compound 2 showed potent inhibitory potential against the enzyme lipoxygenase, while 1 was moderately active.

Evaluation of antioxidant and urease inhibition activities of roots of Glycyrrhiza glabra.

The object of this study is to determine the antioxidant activity of extracts from Glycyrrhiza glabra roots. The parent extract is methanolic extract while its sub fractions were prepared in ethyl acetate, chloroform, and n-butanol. The method based on scavenging activity and reduction capability of 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH).

Sorbicins A and B, new urease and serine protease inhibitory triterpenes from Sorbus cashmiriana.

Two new lupene-type triterpenes, sorbicins A and B, have been isolated from the chloroform-soluble fraction of the MeOH extract from the whole plant of Sorbus cashmiriana, and their structures were elucidated by spectroscopic techniques including 2D NMR. Both compounds displayed urease and α-chymotrypsin inhibitory potential.

Pregnane derivatives from Potentilla evestita.

A new pregnane derivative, 2,6beta,7beta-trihydroxy-4-methyl-19-norpregna-1,3,5(10)-trien-17-one, has been isolated from the ethyl acetate soluble fraction of Potentilla evestita along with a pregnane derivative, 11alpha,17alpha,21-trihydroxypregna-4,16(22)-diene-3,20-dione, that is reported for the first time as a natural product. Their structures were elucidated with the aid of 1H and 13C NMR spectra and by COSY, HMQC, HMBC and NOESY experiments.

Antioxidant and urease inhibitory C-glycosylflavonoids from Celtis africana.

Two new C-glycosylflavonoids celtisides A (1) and B (2) have been isolated from n-butanol-soluble fraction of Celtis africana, along with five known C-glycosylflavonoids vitexin (3), orientin (4), isoswertiajaponin (5), isoswertisin (6), and 2″-O-rhamnosyl vitexin (7) reported for the first time from this species. Their structures were assigned from 1D and 2D NMR spectra. These compounds were investigated for biological activities and showed significant antioxidant and urease inhibitory activities.

Two new 3-C-carboxylated flavones from the rhizomes of Caragana conferta.

Confertins A (1) and B (2), new 3-C-carboxylated flavones, have been isolated from the ethyl acetate soluble fraction of the rhizomes of Caragana conferta. Their structures have been assigned on the basis of spectroscopic studies.

Xanthine oxidase/tyrosinase inhibiting, antioxidant, and antifungal oxindole alkaloids from Isatis costata.

Phytochemical investigations on the ethyl acetate soluble fraction of the whole plant of Isatis costata Linn. (Brassicaseae) led to the isolation of the oxindole alkaloids costinones A (1), B (2), isatinones A (3), B (4), indirubin (5), and trisindoline (6). Compounds 1-6 displayed significant to moderate inhibition against xanthine oxidase enzyme with IC50 values ranging from 90.

In vitro antituberculosis activities of the constituents isolated from Haloxylon salicornicum.

In vitro antituberculosis activities of fractions and pure compounds (1-20) including seven triterpenes, two alkaloids, two cycloheximide derivatives, two coumarins six sterol derivatives and a long chain alcohol, respectively, isolated from Haloxylon salicornicum were determined against Mycobacterium tuberculosis H37Rv. Actively growing cultures were tested by rapid colorimetric method while the stationary phase cultures were tested by drug exposure methods for bactericidal activity. The MIC values were found to be 50 microg/ml for compounds 15, 19 and 20 where as rest of the compounds invariably showed MIC value of 100 microg/ml against the logarithmic phase culture.

Nematicidal natural products from the aerial parts of Buddleja crispa.

Studies on the aerial parts of Buddleja crispa yielded 13 known compounds, nonyl benzoate, hexyl p-hydroxy-cinnamate, ginipin, gardiol, 1-heptacosanol, steroidal galactoside (22 R)-stigmasta-7,9 (11)-dien-22 beta-ol-3beta-O-beta-D-galactopyranoside, 3-methoxy benzoic acid, beta-sitosterol and ursolic acid. Besides this two iridoid galactosides buddlejosides A, buddlejosides B and a benzofuran-type sesquiterpene buddlejone have been isolated from the ETOAC fraction of B. crispa.

Asphorodin, a potent lipoxygenase inhibitory triterpene diglycoside from Asphodelus tenuifolius.

Asphorodin (1), a new diglycoside, has been isolated from the ethyl acetate-soluble fraction of Asphodelus tenuifolius. It showed significant inhibitory activity against the enzyme lipoxygenase in a concentration-dependent manner. The Lineweaver-Burk and Dixon plots indicated that the nature of inhibition was non-competitive.

N-[2-(3-Methyl-1-oxo-1,2-dihydro-pyrrolo-[1,2-a]pyrazin-2-yl)eth-yl]methane-sulfonamide.

In the title compound, C(11)H(15)N(3)O(3)S, the dihedral angle between the five- and six-membered rings is 1.13 (18)°. The ethyl-methane-sulfonamide group is in a (+)synclinal conformation.

2,2-Bis(hy-droxy-meth-yl)-2,3-dihydro-1H-pyrrolizin-1-one.

The title compound, C(9)H(11)NO(3), was prepared by an Aldol reaction of 2,3-dihydro-1H-pyrrolizin-1-one with formaldehyde. The asymmetric unit contains six mol-ecules. The pyrrolizine ring system in each mol-ecule is planar, the maximum atomic deviation being 0.

3-Phenyl-1H-pyrrolo[2,1-c][1,4]oxazin-1-one.

The mol-ecule of the title compound, C(13)H(9)NO(2), is slightly twisted with a dihedral angle of 4.85 (9)° between the nine-membered ring system and the phenyl ring. The nine non-H atoms of the 1H-pyrrolo[2,1-c][1,4]oxazin-1-one system are coplanar [r.

{2-[(Benzo-yloxy)meth-yl]-1-oxo-3H-pyrrolizin-2-yl}methyl benzoate.

The title compound, C(23)H(19)NO(5), was prepared by esterification of 2,2-bis-(hy-droxy-meth-yl)-2,3-dihydro-1H-pyrrolizin-1-one with benzoyl chloride in pyridine·The pyrrolizine ring system is approximately planar with a maximum deviation of 0.008 (2) Å from the least-squares plane; the two phenyl rings are oriented at dihedral angles of 64.26 (11) and 70.

Galinsosides A and B, bioactive flavanone glucosides from Galinsoga parviflora.

Galinsosides A (1) and B (2), new flavanone glucosides together with two known flavanones, 7,3',4'-trihydroxyflavanone (3) and 3,5,7,3',4'-pentahydroxyflavanone (4) have been isolated from an ethyl acetate- soluble fraction of Galinsoga parviflora. Their structures were assigned on the basis of spectral studies. Compound 1 showed significant antioxidant and urease inhibitory activity while compound 2 was moderately active.