Two new (1-2) and eight known (3-10) secondary metabolites were isolated from the rhizomes of Kni... more Two new (1-2) and eight known (3-10) secondary metabolites were isolated from the rhizomes of Kniphofia reflexa Hutchinson ex Codd. Among them, an indane derivative kniphofiarindane (1), and naphthalene derivative kniphofiarexine (2), were identified as new natural products. 1D-and 2D-NMR spectroscopic studies together with single-crystal X-ray diffraction techniques were employed in the structural elucidation of the new compounds, 1 and 2. These compounds were evaluated for their cytotoxic effect against kidney epithelial cell line (LLC-MK2). Compound 3 was found to be highly cytotoxic, while compounds 1, and 10 showed moderate cytotoxicity with CC 50 values of 4.44 ± 0.79, 16.35 ± 1.54, and 11.24 ± 1.22 μg/mL, respectively against the tested standard Gleevec (Imatinib), (CC 50 = 18.50 ± 1.21 μg/mL). Compounds 8, and 9 also showed moderate anti-inflammatory activity (CC 50 = 38.7 ± 4.90, and 20.00 ± 4.40 μg/mL, respectively) against ROS production .
We report new reaction conditions (less corrosive reagents) for the regio-specific synthesis , sp... more We report new reaction conditions (less corrosive reagents) for the regio-specific synthesis , spectroscopic properties, crystal structure, antimicrobial activities and MICs of 1-methyl-4-nitro-1H-imidazole (I). For structure confirmation, X-ray crystallography was performed using crystals obtained from chloroform and hexane (1:1). The structure of the compound (I) was further characterized by FTIR, 1 H NMR, 13 C NMR and EIMS. Important peaks appearing in the EIMS, at the m/z = 127, 111, 97, 81, and 54 arise due to the loss of single electron, loss of O, NO, NO 2 , and loss of NO 2 & HCN respectively. The high intensity peak in the EIMS at m/z = 42 arises due to the loss of NO, CO and HCN from the molecular ion. The correct 1 H NMR (400 MHz, CDCl 3) of (I) shows peaks at 7.76 (ArH, HC‚N), 7.42 (ArH, HC‚C), and 3.82 (N–CH 3) ppm. Further structural studies showed that the driving force for crystallization (self-assembly) and hydrogen bonding (C–H.. .O–NO, 2.57 A ˚) originates from the partial negative oxygen of the nitro (NO 2) group at one end and the partial positive hydrogen (N–CH 3) at another corner of the molecule. Biological assay.org/licenses/by-nc-nd/3.0/). against many (13) microorganisms and fungi showed that the title compound (I) is moderately active against Gram (+), Gram (À) bacteria and fungi.
We describe here the synthesis of dihydropyrimidines derivatives 3a-p, and evaluation of their α-... more We describe here the synthesis of dihydropyrimidines derivatives 3a-p, and evaluation of their α-glucosidase enzyme inhibition activities. Compounds 3b (IC50=62.4±1.5μM), 3c (IC50=25.3±1.26μM), 3d (IC50=12.4±0.15μM), 3e (IC50=22.9±0.25μM), 3g (IC50=23.8±0.17μM), 3h (IC50=163.3±5.1μM), 3i (IC50=30.6±0.6μM), 3m (IC50=26.4±0.34μM), and 3o (IC50=136.1±6.63μM) were found to be potent α-glucosidase inhibitors in comparison to the standard drug acarbose (IC50=840±1.73μM). The compounds were also evaluated for their in vitro cytotoxic activity against PC-3, HeLa, and MCF-3 cancer cell lines, and 3T3 mouse fibroblast cell line. All compounds were found to be non cytotoxic, except compounds 3f and 3m (IC50=17.79±0.66-20.44±0.30μM), which showed a weak cytotoxic activity against the HeLa, and 3T3 cell lines. In molecular docking simulation study, all the compounds were docked into the active site of the predicted homology model of α-glucosidase enzyme. From the docking result, it was observed that most of the synthesized compounds showed interaction through carbonyl oxygen atom and polar phenyl ring with active site residues of the enzyme.
Acta Crystallographica Section E Crystallographic Communications, 2015
In the pyrazole mol-ecule of the title solvate, C15H13BrN4O2·C2H6OS, the dihedral angle between t... more In the pyrazole mol-ecule of the title solvate, C15H13BrN4O2·C2H6OS, the dihedral angle between the benzene ring and the mean plane of the di-hydro-pyrano[2,3-c]pyrazole ring system [r.m.s deviation = 0.031 (2) Å] is 86.71 (14)°. In the crystal, the pyrazole mol-ecules are linked by N-H⋯N hydrogen bonds, forming a layer parallel to (10-1). The pyrazole and dimethyl sulfoxide mol-ecules are connected by an N-H⋯O hydrogen bond.
Acta crystallographica. Section E, Structure reports online, 2013
In the mol-ecule of the title compound, C7H9N3O3, the nitro and carbonyl groups are tilted with r... more In the mol-ecule of the title compound, C7H9N3O3, the nitro and carbonyl groups are tilted with respect to the imidazole ring by 9.16 (6) and 65.47 (7)°, respectively. Neighbouring chains are linked via C-H⋯N and C-H⋯O hydrogen bonds forming two-dimensional slab-like networks lying parallel to (01-1).
Phenylpropanoids are a group of natural products with a wide range of biological and pharmacologi... more Phenylpropanoids are a group of natural products with a wide range of biological and pharmacological importance. They have been isolated from a large number of plants by utilizing a diverse range of chromatographic techniques. We describe here the utilization of normal, reverse phase, and high pressure liquid column chromatographic techniques for the purification of phenylpropanoids from the crude plant extracts. Most important of them is the recycling reverse phase HPLC effectively utilized to purify the highly oxygenated phenylpropanoids glycosides from the butanolic and water extracts. The antioxidant activity of the different phenylpropanoids is also reported on the basis of DPPH, superoxide anion scavenging and Fe(2+)-chelating assays, along with electron spin resonance (ESR) method.
Tandem Knoevenagel-Michael reactions in aqueous diethylamine medium: A greener and efficient appr... more Tandem Knoevenagel-Michael reactions in aqueous diethylamine medium: A greener and efficient approach towards bis-dimedone derivatives, Arabian Journal of Chemistry (2014), doi: http://dx.
A series of 15 novel compounds incorporating the thieno[2,3-b]thiophene moiety were synthesized. ... more A series of 15 novel compounds incorporating the thieno[2,3-b]thiophene moiety were synthesized. The chemical structures of these compounds were deduced from elemental analyses, (1)H NMR, (13)C NMR, and ESI-mass spectral data. The enzyme inhibition potential of these compounds was evaluated, in vitro, against β-glucuronidase, xanthine oxidase, and α-chymotrypsin enzymes. The cytotoxicity was evaluated by a cell viability assay utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye. Among the compounds tested, compound 3 was the most potent β-glucuronidase inhibitor with an IC50 value of 0.9±0.0138μM; it was much more active than the standard, d-saccharic acid 1,4-lactone (IC50=45.75±2.16μM). Compound 12, on the other hand, was the most potent as a xanthine oxidase inhibitor with an IC50 of 14.4±1.2μM. With the characterization of their mechanism of action and with further testing, these compounds could be useful candidates as anticancer drugs. In additi...
Biotransformation of melengestrol acetate (MGA, 17a-acetoxy-6-methyl-16-methylenepregna-4, 6-dien... more Biotransformation of melengestrol acetate (MGA, 17a-acetoxy-6-methyl-16-methylenepregna-4, 6-diene-3,20-dione) (1) was investigated for the first time by using fungal cultures. Incubation of compound 1 with Cunninghamella blakesleeana yielded a new major metabolite, 17a-acetoxy-11bhydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (2). The metabolite 2 was purified by using HPLC, followed by characterization through 1 H-and 13 C-NMR and other spectroscopic techniques. Single crystal X-ray diffraction analysis was used to deduce the three dimensional structures of melengestrol acetate (1) and metabolite 2 for the first time. T-cell proliferation assay was employed to evaluate the immunosuppressant effect of compounds 1 and 2 with IC 50 = 0.5 ± 0.07 and 0.6 ± 0.08 lg/mL, respectively. The results indicated that these compounds possess sixfold potent T-cell proliferation inhibitory activity as compared to the standard prednisolone (IC 50 < 3.1 lg/mL). Both compounds were found to be non-toxic in a 3T3 (mouse fibroblast) cell-based cytotoxicity assay. This discovery of potent anti-inflammatory activity of compounds 1 and 2 can lead the way to develop new immunosuppressant compounds for clinical application.
ABSTRACT Two new compounds, (+)-3,5,7-trihydroxy-3-[3′-hydroxy-2′,4′-dimethoxy-5-(3-methyl-2-bute... more ABSTRACT Two new compounds, (+)-3,5,7-trihydroxy-3-[3′-hydroxy-2′,4′-dimethoxy-5-(3-methyl-2-butenyl)]-phenyl-(3R)-4H-1-benzopyran-4-one (1) and (−)-3-hydroxy-8,9-methylenedioxy-(6aR,11aS)-pterocarpan (2), were isolated from the methanolic extract of Sophora mollis subsp. griffithii. Two known compounds, β-sitosterol (3) and 19βH-lupeol-methyl-ether (4), were also obtained for the first time from this plant. The structures of 1–4 were identified through their spectroscopic data. CD Spectroscopy was also utilized for the structure elucidation of compounds 1 and 2. Compounds 1, 3 and 4 were studied for their effects on immune cells and only 1 was found to be substantially active.
Acta Crystallographica Section E Structure Reports Online, 2012
In the title compound, C(13)H(12)FN(3)O(4), the dihedral angle between the benzene and imidazole ... more In the title compound, C(13)H(12)FN(3)O(4), the dihedral angle between the benzene and imidazole rings is 32.77 (12)°. In the crystal, mol-ecules are linked into a three-dimensional network by C-H⋯O hydrogen bonds.
Two new (1-2) and eight known (3-10) secondary metabolites were isolated from the rhizomes of Kni... more Two new (1-2) and eight known (3-10) secondary metabolites were isolated from the rhizomes of Kniphofia reflexa Hutchinson ex Codd. Among them, an indane derivative kniphofiarindane (1), and naphthalene derivative kniphofiarexine (2), were identified as new natural products. 1D-and 2D-NMR spectroscopic studies together with single-crystal X-ray diffraction techniques were employed in the structural elucidation of the new compounds, 1 and 2. These compounds were evaluated for their cytotoxic effect against kidney epithelial cell line (LLC-MK2). Compound 3 was found to be highly cytotoxic, while compounds 1, and 10 showed moderate cytotoxicity with CC 50 values of 4.44 ± 0.79, 16.35 ± 1.54, and 11.24 ± 1.22 μg/mL, respectively against the tested standard Gleevec (Imatinib), (CC 50 = 18.50 ± 1.21 μg/mL). Compounds 8, and 9 also showed moderate anti-inflammatory activity (CC 50 = 38.7 ± 4.90, and 20.00 ± 4.40 μg/mL, respectively) against ROS production .
We report new reaction conditions (less corrosive reagents) for the regio-specific synthesis , sp... more We report new reaction conditions (less corrosive reagents) for the regio-specific synthesis , spectroscopic properties, crystal structure, antimicrobial activities and MICs of 1-methyl-4-nitro-1H-imidazole (I). For structure confirmation, X-ray crystallography was performed using crystals obtained from chloroform and hexane (1:1). The structure of the compound (I) was further characterized by FTIR, 1 H NMR, 13 C NMR and EIMS. Important peaks appearing in the EIMS, at the m/z = 127, 111, 97, 81, and 54 arise due to the loss of single electron, loss of O, NO, NO 2 , and loss of NO 2 & HCN respectively. The high intensity peak in the EIMS at m/z = 42 arises due to the loss of NO, CO and HCN from the molecular ion. The correct 1 H NMR (400 MHz, CDCl 3) of (I) shows peaks at 7.76 (ArH, HC‚N), 7.42 (ArH, HC‚C), and 3.82 (N–CH 3) ppm. Further structural studies showed that the driving force for crystallization (self-assembly) and hydrogen bonding (C–H.. .O–NO, 2.57 A ˚) originates from the partial negative oxygen of the nitro (NO 2) group at one end and the partial positive hydrogen (N–CH 3) at another corner of the molecule. Biological assay.org/licenses/by-nc-nd/3.0/). against many (13) microorganisms and fungi showed that the title compound (I) is moderately active against Gram (+), Gram (À) bacteria and fungi.
We describe here the synthesis of dihydropyrimidines derivatives 3a-p, and evaluation of their α-... more We describe here the synthesis of dihydropyrimidines derivatives 3a-p, and evaluation of their α-glucosidase enzyme inhibition activities. Compounds 3b (IC50=62.4±1.5μM), 3c (IC50=25.3±1.26μM), 3d (IC50=12.4±0.15μM), 3e (IC50=22.9±0.25μM), 3g (IC50=23.8±0.17μM), 3h (IC50=163.3±5.1μM), 3i (IC50=30.6±0.6μM), 3m (IC50=26.4±0.34μM), and 3o (IC50=136.1±6.63μM) were found to be potent α-glucosidase inhibitors in comparison to the standard drug acarbose (IC50=840±1.73μM). The compounds were also evaluated for their in vitro cytotoxic activity against PC-3, HeLa, and MCF-3 cancer cell lines, and 3T3 mouse fibroblast cell line. All compounds were found to be non cytotoxic, except compounds 3f and 3m (IC50=17.79±0.66-20.44±0.30μM), which showed a weak cytotoxic activity against the HeLa, and 3T3 cell lines. In molecular docking simulation study, all the compounds were docked into the active site of the predicted homology model of α-glucosidase enzyme. From the docking result, it was observed that most of the synthesized compounds showed interaction through carbonyl oxygen atom and polar phenyl ring with active site residues of the enzyme.
Acta Crystallographica Section E Crystallographic Communications, 2015
In the pyrazole mol-ecule of the title solvate, C15H13BrN4O2·C2H6OS, the dihedral angle between t... more In the pyrazole mol-ecule of the title solvate, C15H13BrN4O2·C2H6OS, the dihedral angle between the benzene ring and the mean plane of the di-hydro-pyrano[2,3-c]pyrazole ring system [r.m.s deviation = 0.031 (2) Å] is 86.71 (14)°. In the crystal, the pyrazole mol-ecules are linked by N-H⋯N hydrogen bonds, forming a layer parallel to (10-1). The pyrazole and dimethyl sulfoxide mol-ecules are connected by an N-H⋯O hydrogen bond.
Acta crystallographica. Section E, Structure reports online, 2013
In the mol-ecule of the title compound, C7H9N3O3, the nitro and carbonyl groups are tilted with r... more In the mol-ecule of the title compound, C7H9N3O3, the nitro and carbonyl groups are tilted with respect to the imidazole ring by 9.16 (6) and 65.47 (7)°, respectively. Neighbouring chains are linked via C-H⋯N and C-H⋯O hydrogen bonds forming two-dimensional slab-like networks lying parallel to (01-1).
Phenylpropanoids are a group of natural products with a wide range of biological and pharmacologi... more Phenylpropanoids are a group of natural products with a wide range of biological and pharmacological importance. They have been isolated from a large number of plants by utilizing a diverse range of chromatographic techniques. We describe here the utilization of normal, reverse phase, and high pressure liquid column chromatographic techniques for the purification of phenylpropanoids from the crude plant extracts. Most important of them is the recycling reverse phase HPLC effectively utilized to purify the highly oxygenated phenylpropanoids glycosides from the butanolic and water extracts. The antioxidant activity of the different phenylpropanoids is also reported on the basis of DPPH, superoxide anion scavenging and Fe(2+)-chelating assays, along with electron spin resonance (ESR) method.
Tandem Knoevenagel-Michael reactions in aqueous diethylamine medium: A greener and efficient appr... more Tandem Knoevenagel-Michael reactions in aqueous diethylamine medium: A greener and efficient approach towards bis-dimedone derivatives, Arabian Journal of Chemistry (2014), doi: http://dx.
A series of 15 novel compounds incorporating the thieno[2,3-b]thiophene moiety were synthesized. ... more A series of 15 novel compounds incorporating the thieno[2,3-b]thiophene moiety were synthesized. The chemical structures of these compounds were deduced from elemental analyses, (1)H NMR, (13)C NMR, and ESI-mass spectral data. The enzyme inhibition potential of these compounds was evaluated, in vitro, against β-glucuronidase, xanthine oxidase, and α-chymotrypsin enzymes. The cytotoxicity was evaluated by a cell viability assay utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye. Among the compounds tested, compound 3 was the most potent β-glucuronidase inhibitor with an IC50 value of 0.9±0.0138μM; it was much more active than the standard, d-saccharic acid 1,4-lactone (IC50=45.75±2.16μM). Compound 12, on the other hand, was the most potent as a xanthine oxidase inhibitor with an IC50 of 14.4±1.2μM. With the characterization of their mechanism of action and with further testing, these compounds could be useful candidates as anticancer drugs. In additi...
Biotransformation of melengestrol acetate (MGA, 17a-acetoxy-6-methyl-16-methylenepregna-4, 6-dien... more Biotransformation of melengestrol acetate (MGA, 17a-acetoxy-6-methyl-16-methylenepregna-4, 6-diene-3,20-dione) (1) was investigated for the first time by using fungal cultures. Incubation of compound 1 with Cunninghamella blakesleeana yielded a new major metabolite, 17a-acetoxy-11bhydroxy-6-methyl-16-methylenepregna-4,6-diene-3,20-dione (2). The metabolite 2 was purified by using HPLC, followed by characterization through 1 H-and 13 C-NMR and other spectroscopic techniques. Single crystal X-ray diffraction analysis was used to deduce the three dimensional structures of melengestrol acetate (1) and metabolite 2 for the first time. T-cell proliferation assay was employed to evaluate the immunosuppressant effect of compounds 1 and 2 with IC 50 = 0.5 ± 0.07 and 0.6 ± 0.08 lg/mL, respectively. The results indicated that these compounds possess sixfold potent T-cell proliferation inhibitory activity as compared to the standard prednisolone (IC 50 < 3.1 lg/mL). Both compounds were found to be non-toxic in a 3T3 (mouse fibroblast) cell-based cytotoxicity assay. This discovery of potent anti-inflammatory activity of compounds 1 and 2 can lead the way to develop new immunosuppressant compounds for clinical application.
ABSTRACT Two new compounds, (+)-3,5,7-trihydroxy-3-[3′-hydroxy-2′,4′-dimethoxy-5-(3-methyl-2-bute... more ABSTRACT Two new compounds, (+)-3,5,7-trihydroxy-3-[3′-hydroxy-2′,4′-dimethoxy-5-(3-methyl-2-butenyl)]-phenyl-(3R)-4H-1-benzopyran-4-one (1) and (−)-3-hydroxy-8,9-methylenedioxy-(6aR,11aS)-pterocarpan (2), were isolated from the methanolic extract of Sophora mollis subsp. griffithii. Two known compounds, β-sitosterol (3) and 19βH-lupeol-methyl-ether (4), were also obtained for the first time from this plant. The structures of 1–4 were identified through their spectroscopic data. CD Spectroscopy was also utilized for the structure elucidation of compounds 1 and 2. Compounds 1, 3 and 4 were studied for their effects on immune cells and only 1 was found to be substantially active.
Acta Crystallographica Section E Structure Reports Online, 2012
In the title compound, C(13)H(12)FN(3)O(4), the dihedral angle between the benzene and imidazole ... more In the title compound, C(13)H(12)FN(3)O(4), the dihedral angle between the benzene and imidazole rings is 32.77 (12)°. In the crystal, mol-ecules are linked into a three-dimensional network by C-H⋯O hydrogen bonds.
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