α-Amylase immobilization on amidoximated acrylic microfibres activated by cyanuric chloride.

Enzyme immobilization is one of the most important techniques for industrial applications. It makes the immobilized enzyme more stable and advantageous than the free form in different aspects. α-Amylase was immobilized on 4% cyanuric chloride-activated amidoximated acrylic fabric at pH 7.0 with (79%) maximum efficiency. A field emission scanning electron microscope and Fourier transform infrared were used to confirm the immobilization process. Even after being recycled 10 times, the immobilized enzyme lost just 28% of its initial activity. Owing to immobilization, the pH of the soluble α-amylase was shifted from 6.0 to 6.5. The immobilized α-amylases showed thermal stability at 60°C, and became more resistant to heavy metal ions. The k m values of the immobilized and soluble α-amylases were 9.6 and 3.8 mg starch ml-1, respectively. In conclusion, this method shows that the immobilized α-amylase proved to be more efficient than its soluble form, and hence could be used during saccharification of starch.

Synthesis, antibacterial properties and 2D-QSAR studies of quinolone-triazole conjugates.

A set of 1,2,3-triazole incorporated quinolone antibiotic conjugates 10-15, 17-19 were synthesized via microwave assisted click chemistry technique. Some of the aryl-substituted conjugates 17-19 show promising antibacterial properties against the tested Gram-positive (S. aureus and S. pyogenes) and Gram-negative bacteria (S. typhi) with potency higher than that of the parent antibiotics 1-3. 2D-QSAR modeling supports the observed biological properties.

Synthesis, antimalarial properties and 2D-QSAR studies of novel triazole-quinine conjugates.

Click chemistry technique led to novel 1,2,3-triazole-quinine conjugates 8a-g, 10a-o, 11a-h and 13 utilizing benzotriazole-mediated synthetic approach with excellent yields. Some of the synthesized analogs (11a, 11d-h) exhibited antimalarial properties against Plasmodium falciparum strain 3D7 with potency higher than that of quinine (standard reference used) through in vitro standard procedure bio-assay. Statistically significant BMLR-QSAR model describes the bio-properties, validates the observed biological observations and identifies the most important parameters governing bio-activity.

Synthesis and biological evaluation of fluoropyrazolesulfonylurea and thiourea derivatives as possible antidiabetic agents.

Fluorinated pyrazoles, benzenesulfonylurea and thiourea and their cyclic sulfonylthiourea derivatives were prepared as hypoglycemic agents. The chemistry involves the condensation of 4-hydrazino benzenesulfonamide hydrochloride with fluorochalcones to give pyrazoline derivatives which upon oxidation with bromine water afforded corresponding pyrazoles. Reaction of pyrazolines with isocyanates and isothiocyanates give the corresponding ureas and thioureas. Subsequent cyclization of these thiourea derivatives with ethyl bromoacetate and α-bromoacetophenone yielded the 4-oxothiazolidines and thiazolines, respectively. Preliminary biological screening of the prepared compounds revealed significant antidiabetic activity. Molecular and biological properties calculations revealed favorable drug-like profiles of six compounds. The structure-activity relationship (SAR) and in silico drug relevant properties calculations (HBD, HBA, tPSA, miLogP, molecular weight, % ABS, drug-likeness and drug score) endorse that these compounds are potential leads for future drug discovery study.

1-Substituted carbamoyl and thiocarbamoyl-4,5-dihydro-1H-pyrazoles as possible cytotoxic and antimicrobial agents.

Two series of 1-substituted carbamoyl and thiocarbomoyl derivatives were prepared by either treating the corresponding pyrazole with the appropriate isocyanate and isothiocyanate respectively, or alternatively by condensing the appropriate diketone with the proper substituted semicarbazide or thiosemicarbazide. The structures of the prepared compounds were fully determined by analytical and spectral methods. Preliminary biological screening of the prepared compounds revealed significant antibacterial and cytotoxic activities for some compounds. Compounds 4a2 and 4a3 were found to be the most active against the human colon carcinoma HT29 (11.8 and 7.5 µg/mL, respectively) and human breast cancer MCF 7 (3.4 and 2.6 µg/mL, respectively) cell lines. The structure-activity relationship (SAR) and in silico drug relevant properties (HBD, HBA, tPSA, cLog P, molecular weight, % ABS, drug-likeness and drug score) further confirmed that the compounds are potential lead compounds for future drug discovery study.

Synthesis and biological evaluation of pyrazole chalcones and derived bipyrazoles as anti-inflammatory and antioxidant agents.

A series of bipyrazoles functionalized with sulfonamide, N(1),N(3)-disubstituted sulfonylurea, sulfonylthiourea pharmacophores, and some derived thiazolidinone and thiazoline ring systems were synthesized. The structures of the newly synthesized compounds were substantiated by analytical and diverse spectroscopic data. The anti-inflammatory and antioxidant activity of some of the newly synthesized compounds were tested and the results reveled that compounds 14, 16, 20, 24 and 25 proved to be the most active anti-inflammatory agents according to the Carrageenan-induced rat paw edema bioassay. Whereas, the analogs 14, 16 and 24 were able to exhibit good to moderate antioxidant activity in the DPPH radical-scavenging assay. Hence, compounds 14, 16 and 24 can be considered as lead structures for dual anti-inflammatory and antioxidant activities.

Synthesis and biological evaluation of some novel tetrahydroquinolines as anticancer and antimicrobial agents.

This study reports the synthesis of a series of new 2-amino-3-cyano-8-methyl-4-substituted-5,6,7,8-tetrahydroquinolines along with some derived fused-ring systems. Ten compounds have shown remarkable cytotoxic activity against human colon carcinoma HT29, hepatocellular carcinoma HepG2 and Caucasian breast adenocarcinoma MCF7 cell lines. Six compounds showed considerable broad-spectrum cytotoxic activity among which two proved to be the most active derivatives. Likewise, seven compounds from the series were found to exhibit significant antimicrobial activity and three of them proved to be the most active candidates. Two alkylthio-pyrimido quinolines are suggested as possible antimicrobial and anticancer candidates in the present series.

An efficient approach to the synthesis of highly congested 9,10-dihydrophenanthrene-2,4-dicarbonitriles and their biological evaluation as antimicrobial agents.

An efficient and novel method for the synthesis in moderate to good yield (72%-84%) of a series of 3-amino-1-substituted-9,10-dihydrophenanthrene-2,4-dicarbonitriles 1-5 via one-pot multi-component reactions of aldehydes, malononitrile, 1-tetralone and ammonium acetate has been delineated. Cyclocondensation attempts of aminocyanophenanthrene derivatives 1, 2, 4 and 5 with acetic anhydride in the presence of conc. H2SO4 failed and instead the diacetylamino derivatives 10-13 were obtained. All prepared compounds were structurally elucidated by various spectroscopic methods and X-ray crystallography. N,N-diacetylamino-derivatives of phenanthrene have shown good antimicrobial activity.

Synthesis and biological evaluation of some novel urea and thiourea derivatives of isoxazolo[4,5-d]pyridazine and structurally related thiazolo[4,5-d]pyridazine as antimicrobial agents.

This study reports the synthesis of some novel isoxazolo[4,5-d]pyridazines and structurally related thiazolo[4,5-d]pyridazines, and their biological evaluation as antimicrobial agents. The proposed compounds were designed to contain pharmacophores such as urea, thiourea, sulfonylurea (thiourea) and some derived functionalities that are believed to contribute to the anticipated biological activities. The results revealed that 25 compounds displayed broad spectrum of antibacterial activity, with greater inhibitory effect on the growth of the tested Gram positive strains compared to Gram negative ones. Moreover, 14 compounds were able to produce appreciable growth inhibitory activity against Candida albicans fungus when compared to Clotrimazole. Most of the tested isoxazolo[4,5-d]pyridazines displayed better antimicrobial profile than their corresponding thiazolo[4,5-d]pyridazine congeners. Four compounds namely, p-(3,7-dimethyl-4-oxo-4H-isoxazolo [4,5-d]pyridazine-5-yl)benzenesulfonylthioureas (11c-d), 3-substituted-2-[p-(3,7-dimethyl-4-oxo-4H-isoxazolo[4,5-d]pyridazine-5-yl)-benzene-sufonylimino]-4-oxothiazolidines (13d) and p-(2,7-dimethyl-4-oxo-4H-thiazolo[4,5-d]pyridazin-5-yl)benzenesulfonylthiourea (24c) were found to be most active antimicrobial members in present study.

Synthesis and in vitro antitumor and antimicrobial activity of some 2,3-diaryl-7-methyl-4,5,6,7-tetrahydroindazole and 3,3a,4,5,6,7-hexahydroindazole derivatives.

The synthesis of a series of 2,3-diaryl-7-methyl-4,5,6,7-tetrahydroindazole and 3,3a,4,5,6,7-hexahydroindazole derivatives substituted with various biologically-active function groups with anticipated chemotherapeutic activity is described. 4-(7-methyl-3-aryl-3,3a,4,5,6,7-hexahydro-indazol-2-yl)benzenesulfonamides 2a-c, which were employed as key intermediates in this study, were synthesized by cyclocondensation of 6-arylidene-2-methylcyclohexanones 1a-c with 4-hydrazinobenzenesulfonamide hydrochloride. A detailed discussion of the reactions utilized in the preparation of the intermediate and target compounds is reported, and the structures of the newly synthesized compounds were substantiated with IR, (1)H and (13)C NMR spectral data and elementary microanalyses. Twenty of the newly synthesized compounds were selected by National Cancer Institute (NCI), Maryland, USA, to be evaluated for their antitumor activity and the results revealed that six compounds 3c, 4d,e, 5a,d and 8c exhibited broad spectrum of antitumor activity against most of the tested tumor cell lines. In addition, the in vitro antibacterial and antifungal activities of a number of the target compounds were also tested using the Agar-diffusion method. Some of these compounds have shown significant antibacterial and mild to moderate antifungal activities.

3-cyano-8-methyl-2-oxo-1,4-disubstituted-1,2,5,6,7,8-hexahydroquinolines: synthesis and biological evaluation as antimicrobial and cytotoxic agents.

The synthesis, in vitro antimicrobial and cytotoxic activities of some novel hexahydroquinolines supported with various pharmacophores are described. The results revealed that 18 compounds displayed pronounced activity against Staphylococcus aureus and Escherichia coli bacteria beside a moderate antifungal activity. Compound 25 is the most active candidate with equipotency to ampicillin against S. aureus, E. coli and Pseudomonas aeruginosa, together with an obvious antifungal activity. Additionally, 12 compounds showed remarkable cytotoxic efficiency against human colon carcinoma HT29, hepatocellular carcinoma Hep-G2 and Caucasian breast adenocarcinoma MCF7 cell lines. Among these, the analogs 22 and 25 proved to be the most active cytotoxic members. Collectively, the results would suggest that compounds 22 and 25 could be considered as possible dual antimicrobial-anticancer agents.

Synthesis and characterization of some hydroxypyridone derivatives and their evaluation as antimicrobial agents.

The synthesis, in vitro antimicrobial activities of some novel hydroxy pyridines supported with various pharmacophores is described. Twenty-six out of the tested 58 compounds exhibited variable inhibitory effects on the growth of the tested Gram positive and Gram negative bacteria. The tested compounds revealed better activity against the Gram positive rather than the Gram negative strains. The synthesized hydroxypyridones have shown very significant inhibitory effect against Staphylococcus aureus and Bacillus subtilis. Twelve compounds namely; 5d, 5f, 6a, 6b, 8b, 18b, 18c, 19c, 21d, 22b, 22d and 23d were able to produce appreciable growth inhibitory activity against Candida albicans when compared to Clotrimazole. Among these, 22d proved to be the most potent antifungal agent.

N,N'-Bis[(E)-1-(thio-phen-3-yl)ethyl-idene]ethane-1,2-diamine.

The complete mol-ecule of the title compound, C(14)H(16)N(2)S(2), is generated by a crystallographic inversion centre. The thio-phene residue is close to being coplanar with the imine group [C-C-C-N torsion angle = 6.5 (2)°], and the conformation about the imine C=N bond [1.281 (2) Å] is E. In the crystal, the three-dimensional architecture is consolidated by C-H⋯N, C-H⋯π and S⋯S [3.3932 (7) Å] inter-actions.

2-[(1Z)-(9-Ethyl-9H-carbazol-3-yl)methyl-eneamino]-4,5,6,7-tetra-hydro-1-benzothio-phene-3-carbonitrile-benzene (2/1).

In the title compound, 2C(24)H(21)N(3)S·C(6)H(6), the two independent Schiff base mol-ecules (A and B) in the asymmetric unit differ in the orientation of the tetra-hydro-benzothio-phene ring system with respect to the carbazole ring system by 180° rotation about the C-C bond in the C-C=N-C linkage. The two mol-ecules also differ in the orientation of the ethyl groups [C-N-C-C torsion angle of 90.7 (3)° in mol-ecule A, and -79.4 (3)° in mol-ecule B]. In mol-ecule B, two methyl-ene C atoms of the cyclo-hexene ring are disordered over two sites with occupancies of 0.58 (1) and 0.42 (1). The cyclo-hexene rings in both mol-ecules adopt half-chair conformations. The dihedral angle between the thio-phene ring and the carbazole ring system is 8.07 (9)° in mol-ecule A [3.10 (9)° in mol-ecule B]. In the crystal structure, the independent mol-ecules are linked into dimers by inter-molecular C-H⋯N hydrogen bonds. In addition, C-H⋯π inter-actions are observed.

2-[(E)-(3,4-Dimethyl-isoxazol-5-yl)imino-meth-yl]phenol.

The title compound, C(12)H(12)N(2)O(2), has been synthesized by the reaction of 5-amino-3,4-dimethyl-isoxazole and salicyladehyde. The mol-ecule adopts an E configuration about the central C=N double bond. The dihedral angle between the isoxazole and phenyl rings is 4.2 (2)° and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring motif. The crystal studied was a non-merohedral twin with a domain ratio of 0.834 (4):0.166 (4).

Estrous cycle and ovarian changes in a rat mammary carcinogenesis model after irradiation, tamoxifen chemoprevention, and aging.

PURPOSE: Variation in the effects of selective estrogen receptor modulators (SERMs) on the estrous cycle and reproductive organs during aging could play an important role in the observed heterogeneity of tamoxifen chemoprevention efficacy against breast cancer. METHODS: Of the 1,022 female Sprague Dawley rats enrolled in a long-term tamoxifen chemoprevention study, 87 were randomly chosen from four groups (irradiated, irradiated and tamoxifen treated, tamoxifen treated, and control). Vaginal smears were evaluated for determination of cycle stage, and vaginal pathologic changes. Correlation with the histologic features of reproductive tissues in 43 animals was made. RESULTS: More tamoxifen-treated (21.9%; 7/32) rats had irregular cycling than did control (9%; 3/23) rats. Ovarian granulosa cell hyperplasia was present in 50% (3/6) of tamoxifen-treated rats, and 20% (2/10) of control rats. Endometrial-type cells (ETCs) were present only in tamoxifen-treated (tamoxifen alone 6.25% [2/32]) and tamoxifen/ radiation-treated (28.6% [4/14]) rats. CONCLUSION: The modified Papanicolaou stain used here provided excellent morphologic detail for evaluating the estrous cycle in rodents. Tamoxifen altered vaginal cytologic and ovarian histologic features during aging. Results indicated that tamoxifen had direct and indirect effects on the reproductive tract, causing disturbance of the estrous cycle, shedding of ETCs, and promoting granulosa cell hyperplasia. Understanding of the heterogeneous response to tamoxifen chemoprevention during aging in rodents may provide important insights into the basis for tamoxifen chemoprevention failures in humans.