Synthesis of some new hybride molecules containing several azole moieties and investigation of their biological activities

1,2,4-Triazole-3-one prepared from tryptamine was converted to the corresponding carbothioamides by several steps. Their treatment with ethyl bromoacetate or 4-chlorophenacyl bromide produced the corresponding 5-oxo-1,3-thiazolidine or 3-(4-chlorophenyl)-1,3-thiazole derivatives. Acetohydrazide derivative that was obtained starting from tryptamine, was converted to the corresponding Schiff basis and sulfonamide by the treatment with suitable aldehydes and benzensulphonyl chloride, respectively. 2-[(4-Amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazole-3-yl)methyl]-4-[2-(1H-indole-3-yl)ethyl]-5-methyl-2,4-dihydro-3H-1,2,4-triazole-3-one was synthesized starting from hydrazide via the formation of the corresponding 1,3,4-oxadiazole compound, while the other bitriazole compounds were obtained by intramolecular cyclisation of carbothioamides in basic media. The treatment of 1,2,4-triazole or 1,3,4-oxadiazole compound with several amines generated the corresponding Mannich bases. Ethyl (2-amino-1,3-thiazole-4-yl)acetate was converted to the corresponding 1,3,4-oxadiazole derivative, arylidenehydrazides, 1,2,4-triazole-3-one and 5-oxo-1,3-oxazolidine derivatives by several steps. The structural assignments of new compounds were based on their elemental analysis and spectral (FT IR, ¹H NMR, ¹³C NMR and LC-MS) data. The antimicrobial, antilipase and antiurease activity studies revealed that some of the synthesized compounds showed antimicrobial, antilipase and/or antiurease activity.     

Synthesis and antiviral,insecticidal, and fungicidal activities of gossypol derivatives containing alkylimine,oxime or hydrazine moiety

Gossypol is a part of the cotton plant’s defense system against pathogens and herbivorous insects. To discover gossypol analogs with broad spectrum and high activity, a series of gossypol alkylamine Schiff base, oxime and hydrazone derivatives were synthesised and bioassayed. The biological results indicated that most of these derivatives exhibited higher anti-TMV activity than gossypol. Interestingly, the activities of compounds 10, 15, 18, 20, 23 and 26 were much higher than that of ribavirin. Furthermore, compound 26, which was low toxicity to rat, showed better activity than control plant virus inhibitors in the field. Additionally, allyl amine Schiff base (9) displayed remarkable insecticidal activities against Mythimna separata, Helicoverpa armigera and Ostrinia nubilalis, whereas (pyridin-3-yl)methanamine Schiff base (13) showed excellent activity against Culex pipiens pallens. The fungicidal results revealed that all of compounds exhibited good activity against Physalospora piricola.     

Synthesis of egonol derivatives and their antimicrobial activities

Eighteen derivatives of egonol (A-R) were synthesized and evaluated for their antimicrobial activities against Staphylococcus aureus ATCC 29213, Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231 and Escherichia coli ATCC 8739 microorganisms comparing with egonol. The obtained data reported that compound B exhibited improved activities against all tested bacteria than egonol, others have shown different range of activities.     

Synthesis and fungicidal activity of new N,O-acyl chitosan derivatives

Novel N,O-acyl chitosan (NOAC) derivatives were synthesized to examine their fungicidal activity against the gray mould fungus Botrytis cinerea (Leotiales: Sclerotiniaceae) and the rice leaf blast fungus Pyricularia oryzae (Teleomorph: Magnaporth grisea). The fungicidal activity was evaluated by the radial growth bioassay. NOAC derivatives were more active against the two plant pathogens than chitosan itself, and the effect was concentration dependent. Against B. cinerea, 4-chlorobutyryl chitosan (EC50=0.043%), decanoyl chitosan (EC50=0.044%), cinnamoyl chitosan (EC50=0.045%), and p-methoxybenzoyl chitosan (EC50=0.050%) were the most active (12-13-fold more active than chitosan). (Un)-substituted benzoyl chitosan derivatives were more active against B. cinerea than most of these with N,O-alkyl derivatives. Against P. oryzae chitosan derivatives with lauroyl, methoxy acetyl, methacryloyl and decanoyl were the most active.     

Synthesis,insecticidal, and fungicidal screening of some new quinoline derivatives

This paper describes the synthesis of a series of quinolines graphted with hydrazones, pyrazoles, pyridazine, phthalazine, triazepinone, semicarbazide, and thiomorpholide moieties and four metal complexes. These derivatives were screened against Fusarium oxysporum and the red palm weevil (RPW) Rhynchophorus ferrugineus Oliver (coleopteran: Curculionidae) as palm pathogens. Only chlorinated quinolines were active against these organisms with hydrazones being good fungicides, while those modified with pyrazoles and pyrazines showed moderate insecticidal activity. A unique trihydroxylated hydrazone was active against both organisms, while another hydrazone, the most potent fungicide in this series, exhibited insecticidal activity only upon complexation with Zn²⁺ ions.     

Synthesis of monomethylated dioscin derivatives and their antitumor activities

All possible eight monomethylated dioscin derivatives (1-8) were synthesized. Their inhibitory activities against P388 and A-549 cells were determined, and the results indicate that six of the eight hydroxyls of dioscin are the 'key polar groupings' for tumor inhibitory activities.     

Synthesis of N-substituted iminosugar derivatives and their immunosuppressive activities

Several N-alkyl and hydroxyethyl-substituted iminosugar derivatives, including l-altro and d-galacto epimers, were synthesized and the effects of these synthetic iminosugars on proliferation of mouse splenocytes were evaluated in the MTT assay. The experimental data demonstrated that the N-alkylated d-galacto iminosugars showed better inhibitory activities than l-altro analogues, which might hold potential as immunosuppressive agents.     

Synthesis and antioxidant activity of azole derivatives of hemin

New derivatives of proto- and deuterohemin IX containing tri- and tetrazole rings were synthesized and characterized. A pronounced antioxidant activity was found for these compounds in the Fe(II)/ascorbate-dependent system of lipid peroxidation in murine liver homogenates.     

Synthesis,anti-bacterial and anti-protozoal activities of amidinobenzimidazole derivatives and their interactions with DNA and RNA

Amidinobenzimidazole derivatives connected to 1-aryl-substituted 1,2,3-triazole through phenoxymethylene linkers 7a–7e, 8a–8e, and 9a–9e were designed and synthesised with the aim of evaluating their anti-bacterial and anti-trypanosomal activities and DNA/RNA binding affinity. Results from anti-bacterial evaluations of antibiotic-resistant pathogenic bacteria revealed that both o-chlorophenyl-1,2,3-triazole and N-isopropylamidine moieties in 8c led to strong inhibitory activity against resistant Gram-positive bacteria, particularly the MRSA strain. Furthermore, the non-substituted amidine and phenyl ring in 7a induced a marked anti-bacterial effect, with potency against ESBL-producing Gram-negative E. coli better than those of the antibiotics ceftazidime and ciprofloxacin. UV–Vis and CD spectroscopy, as well as thermal denaturation assays, indicated that compounds 7a and 8c showed also binding affinities towards ctDNA. Anti-trypanosomal evaluations showed that the p-methoxyphenyl-1,2,3-triazole moiety in 7b and 9b enhanced inhibitory activity against T. brucei, with 8b being more potent than nifurtimox, and having minimal toxicity towards mammalian cells.     

Synthesis of new morpholine-connected pyrazolidine derivatives and their antimicrobial,antioxidant, and cytotoxic activities

A simple and convenient one-pot four-component synthesis of morpholine-connected pyrazolidine derivatives 2a–f and 4a–f was developed using direct metal-free catalysis, with the identities of the synthesized compounds confirmed by IR, NMR (¹H and ¹³C), mass spectrometry, and elemental analysis. The prepared compounds were inspected for antimicrobial, antioxidant, and cytotoxic activities.Antimicrobial and antifungal activities against five bacterial and four fungal pathogens, respectively, were investigated using the disc diffusion technique. In antibacterial activity, compounds 2d and 2f (MIC = 2 μg/mL) exhibited significantly higher activity than the standard ciprofloxacin. The results of antifungal assay showed that the activity of compound 4a (MIC = 0.5 μg/mL) was significantly higher than the standard clotrimazole. Antioxidant activity was screened based on ABTS⁺ radical scavenging and linoleic acid peroxidation performance. Compound 4a showed substantial antioxidant (91.3%) activities, as compared with the Trolox standard. Cytotoxicity was evaluated using HepG2 (liver), HeLa (cervical), and MCF-7 (breast) cancer cell lines, with high toxicities observed for 2b (GI₅₀ = 12.2 μm) and 4a (GI₅₀ = 07.8 μm).     

Synthesis and fungicidal activities of novel benzothiophene-substituted oxime ether strobilurins

Twenty-one novel benzothiophene-substituted oxime ether strobilurins, which employed a benzothiophene group to stabilise the E-styryl group in Enoxastrobin (an unsaturated oxime strobilurin fungicide developed by Shenyang Research Institute of Chemical Industry, China) were designed and synthesised. The biological assay indicated that most compounds exhibited good or excellent fungicidal activities, especially against Colletotrichum lagenarium and Puccinia sorghi Schw. In addition, methyl 3-methoxypropenoate oxime ethers and N-methoxy-carbamic acid methyl esters exhibited good in vivo fungicidal activities against Erysiphe graminis, Colletotrichum lagenarium and Puccinia sorghi Schw. under the tested concentrations. Notably, (E,E)-methyl 3-methoxy-2-(2-((((6-chloro-1-(1H-benzo[b]thien-2-yl)ethylidene)amino)oxy)methyl)phenyl)propenoate (5E) exhibited more potent in vivo fungicidal activities against nearly all of the tested fungi at a concentration of 0.39 mg/L compared to Enoxastrobin.     

Synthesis of some imidazolyl-thioacetyl-pyrazolinone derivatives and their antinociceptive and anticancer activities

In this study, some 4-(1,5-diarylimidazol-2-yl)thioacetyl-1-phenyl-2,3-dimethyl-3-pyrazoline-5-one derivatives were prepared by reacting 4-(2-chloroacetyl)-1-phenyl-2,3-dimethyl-3-pyrazoline-5-one and 2-mercapto-1, 5-diarylimidazole derivatives. The antinociceptive and anticancer activities of the compounds obtained were investigated. It was observed that some of the compounds, 2a, 2d, 2g, and 2j, showed remarkable antinociceptive activity, and one of the compounds, 2i, showed weak anticancer activity.     

Synthesis of new uracil derivatives and their sugar hydrazones with potent antimicrobial,antioxidant and anticancer activities

Abstract

6-(4-Chloro-3-nitrophenyl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile (4) was prepared and was reacted with ethyl chloroacetate, hydrazine hydrate, 4-chloroaniline, formaldehyde, acetic anhydride, formic acid, carbon disulfide, 4-cyanobenzaldehyde, triethyl orthoformate, D-sugars, 4-aminoacetophenone, benzoyl choride and cyclohexanone to afford a series of new uracil derivatives (5–18). Examination of some of the prepared compounds for their antimicrobial, antioxidant and anticancer activities was conducted. Among the tested samples, compound 17 was the most active substance against the gram-positive bacteria and was more potent than the reference drug Cefoperazone. Moreover, the antibacterial activity of 17 was higher against gram-negative bacteria. Compounds 6 and 13 reached a higher scavenging ability toward DPPH radicals and are better candidates for antioxidant activity. Also, compounds 6 and 13 had no significant anticancer activity toward liver cancer (Hep G2) and breast cancer (MCF-7) cell lines.     

Synthesis of chalcone derivatives on steroidal framework and their anticancer activities

Chalcone derivatives on estradiol framework have been synthesized. Some of the derivatives showed potent anticancer activity against some human cancer cell lines. Compounds 9 and 19 showed potent activity against MCF-7, a hormone dependent breast cancer cell line. Chalcone 7 was further modified to the corresponding indanone derivative (19) using the Nazarov reaction, which showed better activity than the parent compound against the MCF-7 breast cancer cell line. Active anticancer derivatives were also evaluated for osmotic hemolysis using the erythrocyte as a model system. It was observed that chalcone derivatives showing cytotoxicity against cancer cell lines did not affect the fragility of erythrocytes and hence may be considered as non-toxic to normal cells.     

Synthesis of novel quinolinomatrine derivatives and their insecticidal/acaricidal activities

In continuation of our program to discover natural product-based pesticidal agents, a series of new quinolinomatrine derivatives were prepared. Especially three-dimensional structures of five compounds were unambiguously determined by single-crystal X-ray diffraction. Among them, 21-chloroquinolinomatrine exhibited good insecticidal and acaricidal activities against two crop-threatening insect pests, Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.     

Synthesis and biological activity investigation of azole and quinone hybridized phosphonates

Phosphonates, azoles and quinones are pharmacophores found in bioactive compounds. A series of phosphonates conjugated to azoles and quinones with variable carbon chain lengths were synthesized in 3–4 steps with good yield. Antifungal assay of these compounds showed that ethyl protected phosphates have excellent inhibitory activity against phytopathogenic fungus Fusarium graminearum, and the free-base phosphates have good activity against human pathogenic fungi Aspergillus flavus and Candida albicans. Structure- activity relationship (SAR) studies showed activity increases with longer carbon chain length between phosphonate and anthraquinone analogs consisting of azole and quinone moieties. These newly synthesized compounds also have mild antibacterial activities to Gram positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). Cytotoxicity analysis of these compounds against HeLa cells reveals that the phosphoric acid analogs are less toxic compared to ethyl protected phosphonates. Three leads compounds have been identified with prominent antifungal activity and low cytotoxicity.     

Synthesis of acridinyl-thiazolino derivatives and their evaluation for anti-inflammatory, analgesic and kinase inhibition activities

Variety of N-(4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-ylidene)-2,4(un)substituted acridin-9-amine (4a-o) and 1-[(2,4-(un)substituted acridin-9-yl)-3-(4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-ylidene)]isothiourea (5a-h) derivatives have been synthesized by condensation of 4-phenyl-3-(2',3',4'(un)substituted phenyl)thiazol-2(3H)-imine (3a-g) with 9-chloro-2,4-(un)substituted acridine (1a-c) and 9-isothiocyanato-2,4-(un)substituted acridine (2a-d), respectively. All these compounds were characterized by correct 1H NMR, FT-IR, MS and elemental analyses. These compounds were screened for anti-inflammatory, analgesic and kinase (CDK1, CDK5 and GSK3) inhibition activities. Some compounds exhibited good anti-inflammatory (25-32%) and potent analgesic (50-75%) activities, at 50 mg/kg p.o. A compound, 4o (R1 = H, R2 = OCH3, R3 = CH3, R4 = CH3, R5 = H) exhibited moderate CDK1 (IC50 = 8.5 microM) inhibition activity.     

Synthesis and fungicidal activity of 2,2′-bipyridine derivatives

A series of substituted 2,2′-bipyridine derivatives was prepared using the Kröhnke reaction and alkylation of 4,4′-dimethyl-2,2′-bipyridine. These compounds were screened for fungicidal activity against 9 plant diseases. 5-Phenyl-2,2′-bipyridine exhibited strong preventative and curative fungicidal activity against wheat powdery mildew (Erisyphe graminis) and wheat leaf rust (Puccinia recondita).     

Synthesis of 6-formyl-pyridine-2-carboxylate derivatives and their telomerase inhibitory activities

Twenty-one pyridine-2-carboxylate derivatives were prepared by the coupling of 6-formyl-2-carboxylic acid with the corresponding phenol, thiophenol, and aniline, substituted with various functional groups. Among them, the 3,4-dichlorothiophenol ester (9p) showed the highest in vitro telomerase inhibitory activity and quite significant in vivo tumor suppression activity.     

Synthesis of aminoquinazoline derivatives and their antiproliferative activities against melanoma cell line

The synthesis of a novel series of aminoquinazoline derivatives 1a–r and their antiproliferative activities against A375 human melanoma cell line were described. Among them, six compounds showed superior antiproliferative activities to Sorafenib as a reference compound. In particular, the representative compound 1q bearing chromen-4-one moiety exhibited excellent antiproliferative activity (IC₅₀ = 0.006 μM) and good selectivity over HS27 fibroblast cell line.