Microwave assisted synthesis, antifungal activity, and DFT study of some novel triazolinone derivatives.

A series of some novel 1,2,4-triazol-5(4H)-one derivatives were designed and synthesized under microwave irradiation via multistep reaction. The structures of 1,2,4-triazoles were confirmed by (1)H NMR, MS, FTIR, and elemental analysis. The antifungal activities of 1,2,4-triazoles were determined. The antifungal activity results indicated that the compounds 5c, 5f, and 5h exhibited good activity against Pythium ultimum, and the compounds 5b and 5c displayed good activity against Corynespora cassiicola. Theoretical calculation of the compound 5c was carried out with B3LYP/6-31G (d). The full geometry optimization was carried out using 6-31G(d) basis set, and the frontier orbital energy and electrostatic potential were discussed, and the structure-activity relationship was also studied.

Design, synthesis, antifungal activities and 3D-QSAR of new N,N'-diacylhydrazines containing 2,4-dichlorophenoxy moiety.

A series of new N,N'-diacylhydrazine derivatives were designed and synthesized. Their structures were verified by 1H-NMR, mass spectra (MS) and elemental analysis. The antifungal activities of these N,N'-diacylhydrazines were evaluated. The bioassay results showed that most of these N,N'-diacylhydrazines showed excellent antifungal activities against Cladosporium cucumerinum, Corynespora cassiicola, Sclerotinia sclerotiorum, Erysiphe cichoracearum, and Colletotrichum orbiculare in vivo. The half maximal effective concentration (EC50) of one of the compounds was also determined, and found to be comparable with a commercial drug. To further investigate the structure-activity relationship, comparative molecular field analysis (CoMFA) was performed on the basis of antifungal activity data. Both the steric and electronic field distributions of CoMFA are in good agreement in this study.

Microwave assisted synthesis, antifungal activity and DFT theoretical study of some novel 1,2,4-triazole derivatives containing the 1,2,3-thiadiazole moiety.

In order to investigate the biological activity of 1,2,4-triazole compounds, seventeen novel 1,2,4-triazole derivatives containing 1,2,3-thiadiazole moieties were synthesized by multi-step reactions under microwave assisted conditions. The structures were characterized by 1H-NMR, 13C-NMR, MS and elemental analyses. The target compounds were evaluated for their in vivo fungicidal activities against Corynespora cassiicola, Pseudomonas syringae pv. Lachrymans, and Pseudoperonospora cubensis, and the results indicated that some of the title compounds displayed good fungicidal activities. Theoretical calculations on the title compounds were carried out at the B3LYP/6-31G (d,p). level. The full geometry optimization was carried out using the 6-31G(d,p) basis set, and the frontier orbital energy, atomic net charges were discussed, and the structure-activity relationships were also studied.

2,5-Bis[(3-chloro-benz-yl)sulfan-yl]-1,3,4-thia-diazole.

The complete mol-ecule of the title compound, C(16)H(12)Cl(2)N(2)S(3), is generated by crystallographic twofold symmetry, with the S atom of the thiadiazole ring lying on the rotation axis. The dihedral angle between the mean planes of the 1,3,4-thia-diazole and benzene rings is 87.19 (7)°. In the crystal, mol-ecules are linked by C-H⋯N inter-actions and short S⋯S contacts [3.3389 (9) Å] occur.

Discovery and application of new bacterial strains for asymmetric synthesis of L-tert-butyl leucine in high enantioselectivity.

Discovery of new bacterial strains with fast identification in a miniaturized system was performed for the synthesis of optically active L-tert-butyl leucine. With tert-butyl leucine amide as nitrogen source, one bacterial strain with high conversion and high enantioselectivity was discovered among 120 isolated microorganisms from local soils and identified as Mycobacterium sp. JX009. Glucose and ammonium chloride were examined as the good carbon source and nitrogen source for the cells' growth separately. The cells grew better at 30 °C and at pH 7.5 with higher activity of 2,650 U/l in comparison with other conditions. Cells' stability was improved by immobilization on synthetic resin 0730 without pretreatment. Tert-butyl leucine amide (30 mM) was successfully hydrolyzed by immobilized cells and examined as the highest chemical concentration that cells could endure. After six reaction cycles, the immobilized cells retained 90% activity with production of L-tert-butyl leucine in 98% ee. The results firstly reported the application of new bacterial strain in the hydrolysis of tert-butyl leucine amide to produce optically active L-tert-butyl leucine in an efficient way with investigation in detail.

Improved synthesis of (S)-1-phenyl-2-propanol in high concentration with coupled whole cells of Rhodococcus erythropolis and Bacillus subtilis on preparative scale.

Bioreduction of 1-phenyl-2-propanone to prepare (S)-1-phenyl-2-propanol, a useful pharmaceutical intermediate, was performed with growing cells of Rhodococcus erythropolis JX-021, giving 14 mM (1.9 g/L) product in 99% e.e. at 5 h in the catalysis of 15 mM substrate. The reduction stopped afterwards due to strong inhibition of substrate and formed product, a problem that is often encountered in biotransformation. While the substrate inhibition was solved by stepwise feeding, product inhibition was tackled by different methods: repeated removal of the product by centrifugation, by absorption with Amberlite XAD-7 resin, and by the use of dodecanol as the second phase gave the final product in 58, 68, and 61 mM in the catalysis of 80 mM substrate, respectively. The inhibition was caused by the partial permeabilization of cell membrane of R. erythropolis JX-021, and addition of NADPH or glucose 6-phosphate to such cell culture retained the reduction activity. Therefore, higher productivity in the reduction of 1 with resting cells of R. erythropolis JX-021 was achieved through cofactor regeneration and recycling by the addition of glucose and permeabilized cells of Bacillus subtilis BGSC 1A1 containing a glucose dehydrogenase, giving the product in 62 mM without addition of cofactor and 78 mM with the addition of 0.01 mM NADP(+) in the catalysis of 120 mM substrate. The product e.e. retained 99% during the process which showed industrial possibility.

[Antimicrobial activity and GC-MS analysis of essential oil from lavender extracted by supercritical CO2 extraction and hydrodistillation].

OBJECTIVE: To investigate the antimicrobial activity in vitro and chemical composition of essential oil from lavender extracted by supercritical CO2 extraction (SFE-CO2) process and hydrodistillation. METHOD: The antimicrobial activities against 4 bacteria and 4 fungi strains of these two oils were evaluated by using the agar disc diffusion and agar dilution method to determine the inhibition zone, minimal inhibitory concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC). A GC-MS method was established to determine the chemical components of essential oils. RESULT: These two oils presented remarkable antimicrobiat activities against all tested strains in vitro. Compared with the hydrodistillation product, SFE-CO, oil showed better antimicrobial activity against either bacteria or fungi of which MIC values were 0.63-3.33 g x L(-1) and the MBC/MFC values were 1.04-5.00 g x L(-1). By GC-MS analysis, 34 and 29 compounds identified cover 95.51% and 98. 39% of total peak area of substances appeared. The main differences between SFE-CO2 oil and hydrodistillation oil were the amounts of linalyl acetate and 5-methyl-2-(1-methylethenyl)-4-hexen-1-ol acetate. CONCLUSION: Results presented here may suggest that the essential oil of lavender extracted by SFE-CO2 possesses has better antimicrobial properties, and therefore it is a potential source of antimicrobial ingredients for pharmaceutical industry.

[Genetic structure of Tujia as revealed by Y chromosomes].

Tujia people call themselves "Bizika", which means aboriginal. Genetic study of Tujia is virtually absent. To characterize the genetic structure of Tujia,the distribution of 14 Y haplogroups was studied in Tujia populations sampled from Enshi, Hubei (31 males) and Jishou, Hunan (68 males). A total of eight haplogroups were observed in the Enshi and Jishou populations. The haplogroup frequencies of Tujia were compared with the frequencies of other related ethnic groups, including Northern Han, Southern Han, Tibetan-Burman speaking populations,Daic and Hmong-Mien. The principal component (PC) analysis was conducted and the PCs were plotted to explore the historical migrations. In addition, partial correlation analysis was performed to study the relationship between the first three PCs and the haplogroups. The PC2 revealed a cluster of Tujia groups including Longshan,Yongshun, and Enshi with Lahu, suggesting possible interaction between Tujia and the Di-Qiang groups. However,a similarity between Han and Tujia populations, though differentiated, were also observed. We postulated, by incorporating the results of archaeological and historical evidences, that the Ba people, the ancestors of the Tujia,might be related with Di-Qiang groups and inhabited the Tujia area initially before a substantial interaction with Han and other ethnic groups.

[Origin of Hakka and Hakkanese: a genetics analysis].

Hakka is a distinctive Han Chinese population in Southern China speaking Hakkanese. The origin of Hakka has been controversial. In this report, we analyzed Y chromosomal markers in 148 Hakka males. Principle component analysis of Y-SNP haplotype distribution shows Hakka is clusteed strongly with the Han in Northern China, and is also close to She, a Hmong-Mien-speaking population, while the general Southern Han is fairly close to Daic populations. Admixture analysis revealed that the relative genetic contribution 80.2% (Han), 13% (She) and 6.8% (Kam) in Hakka. The network of Y-STR haplotype of M7 individuals in all concerned populations suggested two possible origins of Hmong-Mien contribution in Hakka: One is from Hubei and the other is from Canton. The Kam contribution in Hakka is likely from Kan-Yue, the ancient aborigine of Kiangsi (Jiangxi). The frequency of 9bp-deletion in Region V of mitochondrial DNA of Hakka is 19.7%, which is quite close to She but far from Han. We therefore concluded that genetically the majority of Hakka gene pool shall come from North Han with She contributing the most among all non-Han groups. Regarding the Hmong-Mien character of Hakkanese, the genetic structure of Hakka shows their core may be Kim-man, the ancient Hmong-Mien. We hypothesized that a great number of Han people from North China join this population in succession. Southern Chinese dialects, such as Hakkanese may also be those languages of Southern aborigines at first, and turn to extant appearance under the continuance effect of Northern Chinese.