Synthesis and Antibacterial Activity of Novel Triazolo[4,3-a]pyrazine Derivatives.

Infectious diseases pose a major challenge to human health, and there is an urgent need to develop new antimicrobial agents with excellent antibacterial activity. A series of novel triazolo[4,3-a]pyrazine derivatives were synthesized and their structures were characterized using various techniques, such as melting point, 1H and 13C nuclear magnetic resonance spectroscopy, mass spectrometry, and elemental analysis. All the synthesized compounds were evaluated for in vitro antibacterial activity using the microbroth dilution method. Among all the tested compounds, some showed moderate to good antibacterial activities against both Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli strains. In particular, compound 2e exhibited superior antibacterial activities (MICs: 32 µg/mL against Staphylococcus aureus and 16 µg/mL against Escherichia coli), which was comparable to the first-line antibacterial agent ampicillin. In addition, the structure-activity relationship of the triazolo[4,3-a]pyrazine derivatives was preliminarily investigated.

Design, synthesis, in vitro and in silico evaluation of novel substituted 1,2,4-triazole analogues as dual human VEGFR-2 and TB-InhA inhibitors.

Cancer is a leading cause of death globally and has been associated with Mycobacterium tuberculosis (Mtb). The angiogenesis-related VEGFR-2 is a common target between cancer and Mtb. Here, we aimed to synthesize and validate potent dual human VEGFR-2 inhibitors as anticancer and anti-mycobacterial agents. Two series of 1,2,4-triazole-based compounds (6a-l and 11a-e) were designed and synthesized through a molecular hybridization approach. Activities of all synthesized compounds were evaluated against human VEGFR-2 in addition to drug-sensitive, multidrug-resistant and extensive-drug resistant Mtb. Compounds 6a, 6c, 6e, 6f, 6h, 6l, 11a, 11d and 11e showed promising inhibitory effect on VEGFR-2 (IC50 = 0.15 - 0.39 µM), anti-proliferative activities against cancerous cells and low cytotoxicity against normal cells. The most potent compounds (6e and 11a) increased apoptosis percentage. Additionally, compounds 6h, 6i, 6l and 11c showed the highest activities against all Mtb strains, and thus were evaluated against enoyl-acyl carrier protein reductase (InhA) which is essential for Mtb cell wall synthesis. Interestingly, the compounds showed excellent InhA inhibition activities with IC50 range of 1.3 - 4.7 µM. Docking study revealed high binding affinities toward targeted enzymes; human VEGFR-2 and Mtb InhA. In conclusion, 1,2,4-triazole analogues are suggested as potent anticancer and antimycobacterial agents via inhibition of human VEGFR-2 and Mtb InhA.

Design, Synthesis and Evaluation of Novel Trichloromethyl Dichlorophenyl Triazole Derivatives as Potential Safener.

The dominance of safener can unite with herbicides acquiring the efficient protection of crop and qualifying control of weeds in agricultural fields. In order to solve the crop toxicity problem and exploit the novel potential safener for fenoxaprop-P-ethyl herbicide, a series of trichloromethyl dichlorobenzene triazole derivatives were designed and synthesized by the principle of active subunit combination. A total of 21 novel substituted trichloromethyl dichlorobenzene triazole compounds were synthesized by substituted aminophenol and amino alcohol derivatives as the starting materials, using cyclization and acylation. All the compounds were unambiguously characterized by IR, 1H-NMR, 13C-NMR, and HRMS. A greenhouse bioassay indicated that most of the title compounds could protect wheat from injury caused by fenoxaprop-P-ethyl at varying degrees, in which compound 5o exhibited excellent safener activity at a concentration of 10 µmol/L and was superior to the commercialized compound fenchlorazole. A structure-activity relationship for the novel compounds was determined, which demonstrated that those compounds containing benzoxazine groups showed better activity than that of oxazole-substituted compounds. Introducing a benzoxazine fragment and electron-donating group to specific positions could improve or maintain the safener activity for wheat against attack by the herbicide fenoxaprop-P-ethyl. A molecular docking model suggested that a potential mechanism between 5o and fenoxaprop-P-ethyl is associated with the detoxication of the herbicide. Results from the present work revealed that compound 5o exhibited good crop safener activities toward wheat and could be a promising candidate structure for further research on wheat protection.

Crystal structure of 1-anilino-5-methyl-1H-1,2,3-triazole-4-carb-oxy-lic acid monohydrate.

In the mol-ecular structure of the title compound, C10H10N4O2·H2O, the angle between the triazole and arene rings is 87.39 (5)°. The water of crystallization connects the mol-ecules in the crystal packing. The crystal structure exhibits N-H⋯O, O-H⋯O and O-H⋯N inter-actions, resulting in the formation of a three-dimensional framework. The inter-molecular inter-actions were identified and qu-anti-fied using Hirshfeld surface analysis.

Theoretical study of the heats of formation, detonation properties, and bond dissociation energies of substituted bis-1,2,4-triazole compounds.

The heats of formation (HOFs), detonation properties, and bond dissociation energies (BDEs) of a series of energetic bis-1,2,4-trizaole compounds with different substituents were studied using density functional theory at the 6-311 + G(2df, 2p) level. The HOF results indicated that the presence of the substituents -NH2, -NO2, -NHNO2, and -N3 markedly increases the HOFs of bis-1,2,4-trizaole compounds. The calculated detonation velocities and detonation pressures indicated that the presence of the substituents -NH2, -NO2, -NHNO2, -CH(NO2)2, and -OH strongly enhances the detonation properties of bis-1,2,4-trizaole compounds. The BDEs results indicated that the presence of the substituents -H, -NH2, and -OH substituent groups greatly improves the thermal stabilities of bis-1,2,4-trizaole compounds. Based on its detonation properties and BDEs, one of the bis-1,2,4-trizaole compounds (B6) is a potential alternative explosive to 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX).

Highly potent anti-leishmanial derivatives of hederagenin, a triperpenoid from Sapindus saponaria L.

Leishmaniasis is a neglected tropical disease (NTDs), endemic in 88 countries that affect more than 12 million people. Current drugs are limited due to their toxicity, development of biological resistance, length of treatment and high cost. Thus, the search for new effective and less toxic treatments is an urgent need. In this study, we report the synthesis of 3 new amide derivatives of hederagenin (22-24) with yields between 70% and 90%, along with 57 other derivatives of hederagenin (1-21, 25-60) carrying different groups at C-28 previously reported by our group, and the results of their in vitro ability to inhibit the growth of Leishmania infantum. Some derivatives (3, 4, 44, 49 and 52), showed activity at micromolar level and low toxicity against BGM and HepG2 cells. Moreover, the ability of hederagenin derivatives 3 (IC50 = 9.7 µM), 4 (12 µM), 44 (11 µM) and 49 (2 µM), to prevent proliferation of intracellular amastigote forms of L. infantum and their higher selectivity index and low toxicity compared to commercial positive drug control of choice (potassium antimonyl tartrate trihydrate) (IC50 = 80 µM, SI = 0.1), make these compounds promising candidates for the treatment of leishmaniasis.

Orthogonal design optimization in synthesis of novel triazole antifungal com-pounds as key intermediates / 药学实践杂志

Objective To optimize novel triazole antifungal compounds synthesis of key intermediates.Methods The or-thogonal experimental design is used,emphasizing on four factors including the reaction temperature,the weight ratio of mate-rial,reaction time and solvent on the yield.Results The effect of reaction temperature on the reaction yield is the most signifi-cant,followed by reaction time ;the weight ratio of material and solvent on the yield impact is not obvious.Conclusion The new technology has several advantages and yields up to about 50%,less reactive impurities,easy post processing.