Synthesis and spectral characterization of new 1,3,5-triaryl-2-pyrazolines highlighting effect of alkyloxy chain length on fluorescence.

A series of new 1,3,5-triaryl-2-pyrazolines (1b-12b) having one to twelve carbon alkyloxy side chains were synthesized and characterized on the basis of their spectral (IR, (1)H &(13)C NMR and GC-MS) and microanalytical data. The UV-Vis and emission spectroscopy was used to study the effect of alkyloxy chain length on absorption and fluorescence properties of 1b-12b. All the compounds showed fluorescence in the blue region of the visible spectrum. Interestingly, the alkyloxy chain length strongly affects the emission intensity of 1,3,5-triaryl-2-pyrazoline framework without causing any major blue- or red-shift in the emission wavelength (λmax(em)). The absorption and emission maxima (λmax(abs) &λmax(em)) for compounds (1b-12b) were observed in the range of 337-364nm and 454-464nm, respectively. Furthermore, the effect of fluorine substituent on aryl ring present at 3-position of pyrazoline moiety on fluorescence properties is also discussed.

Synthesis, spectral characterization, self-assembly and biological studies of N-acyl-2-pyrazolines bearing long alkoxy side chains.

A series of new pyrazoline derivatives (1b-4c) bearing N-acyl arms and nine to twelve carbon long alkoxy side chains was synthesized and characterized on the basis of spectroscopic data and microanalysis. The nature of self-assembly to understand the interplay of alkoxy chain crystallization and various supramolecular interactions was investigated using single crystal X-ray diffraction studies. Interesting self-assembled supramolecular structures of 1b and 4c were observed in the crystal lattice owing to various CH⋯O, H⋯H, CH⋯π, lonepair⋯π and π⋯π interactions. Further, all the synthesized compounds (1b-4c) were screened for their in vitro antifungal and anti-inflammatory activities. Compounds 2b, 3b, 2c and 3c showed significant to moderate antifungal activity against Microsporum canis whereas most of the other compounds were found inactive against all the five tested fungal strains. Good anti-inflammatory activity was observed for compounds 1b with IC50 value 331 µM compared to 273 µM for Indomethacine, a standard reference drug. The bio-activity data demonstrates the relationship between lipophilicity, solubility and bioavailability.

Total synthesis, cytotoxic effects of damnacanthal, nordamnacanthal and related anthraquinone analogues.

Naturally occurring anthraquinones, damnacanthal (1) and nordamnacanthal (2) were synthesized with modified reaction steps and investigated for their cytotoxicity against the MCF-7 and K-562 cancer cell lines, respectively. Intermediate analogues 2-bromomethyl-1,3-dimethoxyanthraquinone (5, IC50 = 5.70 ± 0.21 and 8.50 ± 1.18 mg/mL), 2-hydroxymethyl-1,3-dimethoxyanthraquinone (6, IC50 = 12.10 ± 0.14 and 14.00 ± 2.13), 2-formyl-1,3-dimethoxyantharquinone (7, IC50 = 13.10 ± 1.02 and 14.80 ± 0.74), 1,3-dimethoxy-2-methylanthraquinone (4, IC50 = 9.40 ± 3.51 and 28.40 ± 2.33), and 1,3-dihydroxy-2-methylanthraquinone (3, IC50 = 25.60 ± 0.42 and 28.40 ± 0.79) also exhibited moderate cytotoxicity against MCF-7 and K-562 cancer cell lines, respectively. Other structurally related compounds like 1,3-dihydroxyanthraquinone (13a, IC50 = 19.70 ± 0.35 and 14.50 ± 1.28), 1,3-dimethoxyanthraquinone (13b, IC50 = 6.50 ± 0.66 and 5.90 ± 0.95) were also showed good cytotoxicity. The target compound damnacanthal (1) was found to be the most cytotoxic against the MCF-7 and K-562 cancer cell lines, with IC50 values of 3.80 ± 0.57 and 5.50 ± 1.26, respectively. The structures of all compounds were elucidated with the help of detailed spectroscopic techniques.

Synthesis, characterization and fluorescent property evaluation of 1,3,5-triaryl-2-pyrazolines.

A series of 1,3,5-triaryl-2-pyrazolines was synthesized by dissolving the corresponding 4-alkoxychalcones in glacial acetic acid containing a few drops of concentrated hydrochloric acid. This step was followed by the addition of (3,4-dimethylphenyl) hydrazaine hydrochloride. Finally the target compounds were precipitated by pouring the reaction mixture onto crushed ice. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The 1,3,5-triaryl-2-pyrazolines bearing homologous alkoxy groups were found to possess fluorescence properties in the blue region of the visible spectrum when irradiated with ultraviolet radiation. The fluorescent behavior of these compounds was studied by UV-Vis and emission spectroscopy, performed at room temperature.

Synthesis, characterization and antifungal evaluation of 5-substituted-4-amino-1,2,4-triazole-3-thioesters.

A series of 5-substituted-4-amino-1,2,4-triazole-3-thioesters was synthesized by converting variously substituted organic acids successively into the corresponding esters, hydrazides, 5-substituted-1,3,4-oxadiazole-2-thiols, 5-substituted-1,2,4-triazole-2-thiols and 5-substituted-1,3,4-oxadiazole-2-thioesters. Finally the target compounds were obtained by refluxing 5-substituted-1,3,4-oxadiazole-2-thioesters in the presence of hydrazine hydrate and absolute alcohol. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The synthesized compounds were evaluated for their in vitro antifungal activity. Some of the evaluated compounds possessed significant antifungal activity as compared to a terbinafine standard.

Isolation and synthesis of flavonols and comparison of their antioxidant activity.

Phytochemical investigation of the leaves of Astragalus beckari yielded four flavonol aglycones, namely kaempferol, quercetin, 5-deoxy kaempferol and fisitin. These isolated compounds were then synthesised in the laboratory using the Algar-Flyn-Oyamad reaction. Antioxidant activity of both the isolated and synthesised flavonoids was compared using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay method. The isolated flavonoids were found to be more active.

Synthesis of novel fluorescent cyclohexenone derivatives and their partitioning study in ionic micellar media.

An approach is demonstrated toward the synthesis of four novel cyclohexenone derivatives (CDs) via a convenient route of Michael addition of ethyl acetoacetate. The molecular structures of CDs were confirmed by means of FT-IR, (1)H NMR, EIMS, UV and also by X-ray single crystal structure analysis. CDs are strongly fluorescent compounds and their fluorescent spectra exhibits intense violet fluorescence. To model the binding to biological membranes the behavior of CDs in micellar solutions of a cationic surfactant, cetyltrimethylammonium bromide (CTAB) and an anionic surfactant, sodium dodecylsulfate (SDS) has also been examined. The characteristics of partition and binding interactions of CDs with CTAB and SDS were investigated by UV-Visible and fluorescence spectroscopic techniques. Higher values of all mentioned interactions in case of CTAB, compared to SDS, indicate that there are greater interactions between the CDs and CTAB than with SDS.

Interaction of flavonoids, the naturally occurring antioxidants with different media: a UV-visible spectroscopic study.

Quantitative parameters for interaction of flavonoids-the naturally occurring antioxidants, with solvents and surfactants are determined using UV-visible absorption spectroscopy. The availability of flavonoids; kaempferol, apigenin, kaempferide and rhamnetin in micelles of sodium dodecyl sulfate (SDS) is reflected in terms of partition coefficient, K(c). Thermodynamic calculations show that the process of transfer of flavonoid molecules to anionic micelles of SDS is energy efficient. A distortion in flavonoid's morphology occurs in case of kaempferol and apigenin in surfactant and water, exhibited in terms of a new band in the UV region of electronic spectra of these flavonoids. The partition coefficients of structurally related flavonoids are correlated with their antioxidant activities.

(E)-4-Nitro-benzaldehyde oxime.

In the title compound, C(7)H(6)N(2)O(3), the planes containing the CNO and ONO atoms subtend dihedral angles of 5.47 (5) and 8.31 (5)°, respectively, with the benzene ring. In the crystal structure, inter-molecular O-H⋯N hydrogen bonds link the mol-ecules into centrosymmetric dimers with an R(2) (2)(6) graph-set motif.

1-{5-[4-(Hex-yloxy)phen-yl]-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl}ethanone.

The crystal structure of the title compound, C(23)H(28)N(2)O(2), is composed of discrete mol-ecules with bond lengths and angles quite typical for pyrazoline derivatives of this class. The plane containing the pyrazoline unit is nearly planar with the mean plane of the phenyl ring at the 3-position, making a dihedral angle of 1.96 (3)°. The crystal packing is stabilized by weak C-H⋯π inter-actions involving both of the aromatic rings.

(3E)-3-[4-(Dimethyl-amino)-phen-yl]-1-(4-hy-droxy-phen-yl)prop-2-en-1-one.

The asymmetric unit of the title compound, C(17)H(17)NO(2), contains two crystallographically independent mol-ecules. Both mol-ecules adopt a trans configuration about the C=C bond, with the C-C=C-C fragments in the two mol-ecules twisted in opposite directions [torsion angles of 174.2 (2) and -175.8 (2)°]. The two benzene rings in each of the mol-ecules make dihedral angles of 20.21 (6) and 48.64 (4)°. In the crystal, adjacent mol-ecules are linked by O-H⋯O hydrogen bonds into infinite polymeric chains.

1-[5-(4-Meth-oxy-phen-yl)-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl]ethanone.

The title mol-ecule, C(18)H(18)N(2)O(2), is V-shaped with the pyrazoline moiety being inclined to the adjacent phenyl ring by an angle of 6.49 (9)°, while the 4-meth-oxy-substituted ring is inclined to the pyrazoline ring by 82.99 (9)°. In the crystal, adjacent mol-ecules are linked by C-H⋯O inter-actions, forming chains propagating in [100]. There are also C-H⋯π inter-actions involving adjacent mol-ecules and those related by an inversion center.

2,2'-(1-Phenyl-1H-pyrazole-3,5-di-yl)diphenol.

The title compound, C(21)H(16)N(2)O(2), was derived from 1-(2-hydroxy-phen-yl)-3-(-methoxy-phen-yl)propane-1,3-dione. The mol-ecular structure of the title compound is stabilized by an intra-molecular O-H⋯N hydrogen bond. The dihedral angle between the hydroxy-phenyl ring involved in this intra-molecular hydrogen bond and the pyrazole ring is significantly smaller [10.07 (6)°] than the dihedral angle between the pyrazole and the other hydroxy-phenyl ring [36.64 (5)°]. The benzene ring makes a dihedral angle of 54.95 (3)° with the pyrazole ring. The crystal packing is stabilized by O-H⋯O and O-H⋯N hydrogen bonds.

Ethyl 4-(4-bromo-phen-yl)-6-(4-ethoxy-phen-yl)-2-oxocyclo-hex-3-enecarboxyl-ate.

The title compound, C(23)H(23)BrO(4), is an inter-mediate in the synthesis of fused heterocycles. In the title mol-ecule, the cyclo-hexene ring has a distorted half-chair conformation. The bromo-phenyl ring and the mean plane of the cyclo-hexene ring form a dihedral angle of 13.8 (3)°, whereas the benzene and cyclo-hexene rings are approximately perpendicular [88.44 (17)°]. There are only weak C-H⋯O and C-H⋯π inter-molecular inter-actions.

2-[3-(4-Methoxyphen-yl)-1-phenyl-1H-pyrazol-5-yl]phenol.

The title compound, C(22)H(18)N(2)O(2), was derived from 1-(2-hydroxy-phen-yl)-3-(4-methoxy-phen-yl)propane-1,3-dione. The central pyrazole ring forms dihedral angles of 16.83 (5), 48.97 (4) and 51.68 (4)°, respectively, with the methoxy-phenyl, phenyl and hydroxy-phenyl rings. The crystal packing is stabilized by O-H⋯N hydrogen bonding.

(E)-3-[4-(Pent-yloxy)phen-yl]-1-phenyl-prop-2-en-1-one.

The title compound, C(20)H(22)O(2), crystallizes with two independent mol-ecules in the asymmetric unit. In each mol-ecule, all the non-H atoms lie in a common plane (r.m.s. deviations of 0.098 and 0.079 Å). There is a π-π stacking inter-action in the crystal structure. The central aromatic rings of the two mol-ecules, which are stacked head-to-tail one above the other, are separated by centroid-to-centroid distances of 3.872 (13) and 3.999 (10) Å.

4-Hex-yloxy-3-methoxy-benzaldehyde.

The title compound, C(14)H(20)O(3), is a synthetic analogue with a long aliphatic side chain of the important food additive and flavoring agent, vanillin. There are two independent mol-ecules in the asymmetric unit, each having an essentially planar conformation (r.m.s. deviations of 0.023 and 0.051Å for all non-H atoms of the two mol-ecules in the asymmetric unit).

Pharmacological basis for use of Pistacia integerrima leaves in hyperuricemia and gout.

ETHNOPHARMACOLOGICAL SIGNIFICANCE: Pistacia integerrima Stew ex. Brandis is an important component of commonly dispensed traditional dosage forms. We wished to determine whether polyphenolic constituents of this plant could be useful in oxidative stress and have potential to counter hyperuricemia. MATERIAL AND METHODS: Radical scavenging activity was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and xanthine oxidase (XO) inhibitory activity assay in vitro. Fructose (FRS) induced hyperuricemic animal model was used to asses the serum uric acid (UA) lowering effect by plant products. RESULTS: Ethyl acetate and n-BuOH fractions had the highest DPPH radical scavenging activity. Fifty percent inhibitory concentration (IC(50)) was 6 and 7.6 microg/ml respectively. It was less than quercetin (IC(50) 0.95 microg/ml) and ascorbic acid (IC(50) 1.76 microg/ml). Xanthine oxidase inhibitory activity was comparable between n-BuOH and EtOAc (IC(50) 19 and 20 microg/ml) extracts but less than quercetin (IC(50) 0.65 microg/ml) and allopurinol (IC(50) 0.10 microg/ml). The antioxidant activity as well as the inhibitory activity towards the enzyme XO by quercetin-3-O-beta-d-glucopyranoside (5), kaempferol-3-O-beta-d-glucopyranoside (6), quercetin-3-O-(6''-O-syringyl)-beta-d-glucopyranoside (7), kaempferol-3-O-(4''-O-galloyl)-alpha-l-arabinopyranoside (8), rutin (4) together with aglycons, quercetin (1), kaempferol (2) and apigenin (3) was promising to continue in vivo hypouricemic studies. Ethyl acetate extract had dose dependent UA lowering effect in hyperuricemic mice. This effect was comparable with quercetin but less than allopurinol. CONCLUSIONS: These findings are encouraging to plan clinical studies in hyperuricemic patients.

3-(2-Hydroxy-phen-yl)-5-(2-methoxy-phenyl)-1H-pyrazole.

The title compound, C(16)H(14)N(2)O(2), was derived from 1-(2-hydroxy-phen-yl)-3-(2-methoxy-phen-yl)propane-1,3-dione. The mol-ecule is essentially planar (r.m.s. deviation for all non-H atoms = 0.089 Å). Two intra-molecular hydrogen bonds stabilize the mol-ecular conformation and one N-H⋯O hydrogen bond stabilizes the crystal structure.

2-[5-(4-Hydroxy-phen-yl)-1-phenyl-1H-pyrazol-3-yl]phenol.

The title compound, C(21)H(16)N(2)O(2), was derived from 1-(2-hydroxy-phen-yl)-3-(4-methoxy-phen-yl)propane-1,3-dione. The pyrazole ring and one of the hydr-oxy-substituted benzene rings are approximately coplanar, forming a dihedral angle of 7.5 (3)°. The relative conformation of these rings may be influenced by an intra-molecular O-H⋯N hydrogen bond. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds involving different hydr-oxy groups of symmetry-related mol-ecules form extended chains along [201].