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To further explore the structure activity relationships (SARs) of our previously discovered antifungal lead compound (1), a series of biphenyl imidazole analogues were designed, synthesized and evaluated for their in vitro antifungal activity. Many of the synthesized compounds showed excellent activity against Candida albicans and Candida tropicalis. Among these compounds, 2-F substituted analogue 12m displayed the most remarkable in vitro activity against C. albicans, C. neoformans, A. fumigatus and fluconazole-resistant C. alb. strains, which is superior or comparable to the activity of the reference drugs fluconazole and itraconazole. Notably, the compound 12m exhibited low inhibition profiles for various human cytochrome P450 isoforms and showed low toxicity to mammalian A549 cells and U87 cells. The SARs and binding mode established in this study will be useful for further lead optimization.

N6-methyladenine (6mA), as a newly reported epigenetic marker, plays significant roles in regulation of various biological processes in eukaryotes. However, the effect of 6mA on human DNA replication remain elusive. In this work, we used Y-family human DNA polymerase η as a model to investigate the kinetics of bypass of 6mA by hPol η. We found 6mA and its intermediate hypoxanthine (I) on template partially inhibited DNA replication by hPol η. dTMP incorporation opposite 6mA and dCMP incorporation opposite I can be considered as correct incorporation. However, both 6mA and I reduced correct incorporation efficiency, next-base extension efficiency, and the priority in extension beyond correct base pair. Both dTMP incorporation opposite 6mA and dCTP opposite I showed fast burst phases. However, 6mA and I reduced the burst incorporation rates (kpol) and increased the dissociation constant (Kd,dNTP), compared with that of dTMP incorporation opposite unmodified A. Biophysical binding assays revealed that both 6mA and I on template reduced the binding affinity of hPol η to DNA in binary or ternary complex compared with unmodified A. All the results explain the inhibition effects of 6mA and I on DNA replication by hPol η, providing new insight in the effects of epigenetically modified 6mA on human DNA replication.

To further enhance the anti-Aspergillus efficacy of our previously discovered antifungal lead compound 1, a series of benzoheterocycle analogues were designed, synthesized and evaluated for their in vitro antifungal activity. The most promising compounds 13s and 14a exhibited excellent antifungal activity against C. albicans, C. neoformans, A. fumigatus and fluconazole-resistant C. albicans strains, that was superior or comparable to those of the reference drugs fluconazole and voriconazole. GC-MS analyses suggested that the novel compound 13s might have a similar mechanism to fluconazole by inhibiting fungal lanosterol 14α-demethylase (CYP51). Furthermore, compounds 13s and 14a exhibited low inhibition profiles for various human cytochrome P450 isoforms as well as excellent blood plasma stability.

To further enhance the anti-Aspergillus efficacy of our previously discovered antifungal lead compounds (1), a series of aromatic heterocyclic derivatives were designed, synthesized and evaluated for in vitro antifungal activity. Many of the target compounds showed good inhibitory activity against Candida albicans and Cryptococcus neoformans. In particular, the isoxazole nuclei were more suited for improving the activity against Aspergillus spp. Among these compounds, 2-F substituted analogues 23g and 23h displayed the most remarkable in vitro activity against Candida spp., C. neoformans, A. fumigatus and fluconazole-resistant C.alb. strains, which is superior or comparable to the activity of the reference drugs fluconazole and voriconazole. Notably, the compounds 23g and 23h exhibited low inhibition profiles for various isoforms of human cytochrome P450 and excellent blood plasma stability.

Fungal infections have became a serious medical problem due to their high incidence and mortality. We describe the discovery and structure-activity relationships studies (SARs) of a series of novel biphenyl imidazole derivatives with excellent antifungal activities against Candida albicans and Cryptococcus neoformans. The most promising compounds 12f-g and 19a-b exhibited excellent activity with minimum inhibitory concentration (MIC) values in the range of 0.03125-2μg/mL. Preliminary mechanism studies showed that the potent antifungal activity of compound 12g stemed from inhibition of CYP51 in Candida albicans. Furthermore, compounds 12g and 19b exhibited low inhibition profiles for various human cytochrome P450 isoforms. The SARs and binding mode established in this study will be useful for further lead optimization.

Application of nitrogen (N) fertilizer usually increases grain yield (GY) and grain protein content (GPC) simultaneously. But low GPC is desirable in soft wheat (Triticum aestivum L.). To break the unexpected link, we investigated the combined effects of reduced N rate, increased plant density on GY, nitrogen agronomic efficiency (NAE) and GPC targeting biscuit-making of two soft wheat cultivars. The field experiments involved four N rates (240, 180, 120 and 0 kg N ha−1) and three plant densities (180, 240 and 300 × 104 plants ha−1). Reducing N rate improved grain quality for biscuit-making and NAE in soft wheat, but resulted in lower dry matter accumulation and caused a significant GY loss. With the N rate ranged from 240 to 0 kg N ha−1, GY loss of 16.28–18.54 kg ha−1 was observed for every 1 kg N ha−1 reduction. Increasing plant density significantly enhanced the population dry matter accumulation and partially compensated for GY loss caused by reduced N via increasing the number of effective ears, meanwhile further improved grain quality and NAE. When the plant density increased from 180 to 300 × 104 plants ha–1, increasing 1.0 × 104 plants ha–1 led to an increment in average GY of 4.79, 6.78 and 3.98 kg ha–1 under 180, 120 and 0 kg N ha−1, respectively. The reduction of 1 kg N ha–1 was replaced by increasing app. 2.40–4.09 × 104 plants ha–1 to maintain same GY. The decrease in GPC by the combination of reduced N rate and increased plant density was mainly attributed to the variations in pre-anthesis accumulated N in vegetative organs as well as the whole plant. Moreover, reducing N rate showed a more remarkable effect on GPC than increasing plant density, and their interaction effect was significant. Our study therefore provided an agronomic approach to balance GY and GPC targeting biscuit-making in soft wheat production by the combination of low N rate and high plant density.

To assess the prevalence and molecular characteristics of Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi in natural grazing local breed cattle, 513 fecal samples from Tibetan yellow cattle and cattle–yaks were tested for these pathogens. Cryptosporidium, G. duodenalis and E. bieneusi in Tibetan yellow cattle prevalence were 0.7% (3/442), 3.8% (17/442) and 2.5% (11/442), respectively. Cryptosporidium bovis (n = 3), G. duodenalis assemblages A (n = 2) and E (n = 15) were identified based on sequence analysis. Among three E. bieneusi genotypes, I (n = 7), EbpC (n = 2) and CHC8 (n = 2) detected, EbpC was classified into Group 1, which has a significant zoonotic importance, whereas genotypes I and CHC8 belonged to Group 2. None of these pathogens was identified in cattle–yaks. The presence of zoonotic C. bovis, assemblage A and EbpC indicates Tibetan yellow cattle may be a potential spread source of intestinal pathogens with a zoonotic transmission risk. The relationships between natural free–range mode and the prevalence or genetic diversity of these pathogens need be confirmed in further studies.

Egg production is determined by the function of ovary and is regulated by the hypothalamic-pituitary-ovary axis. The mechanism by which the ovary regulates egg production, however, is still poorly understood. The purpose of this study is to compare the transcriptome difference in ovary of relatively greater and lesser egg producing chickens, and to screen candidate genes related to egg production. A RNA sequencing was performed to analyze and compare the mRNA in ovarian tissues of relatively greater and lesser egg producing chickens. A total of 4 431 new genes expressed in the chicken ovary were mined. There were 305 differentially expressed genes (DEGs) identified between the relatively greater and lesser egg producing hens. Gene ontology analysis identified five candidate genes related to egg production, including ZP2, WNT4, AMH, IGF1, and CYP17A1 genes. Tissue expression profiles indicated these five candidate genes were highly expressed in chicken ovarian tissues, indicating a potential role in regulating chicken ovarian function and egg production. The KEGG analysis indicated the neuroactive ligand-receptor interaction pathway might have an important function in regulation of egg production. In addition, four known pathways related to reproduction were detected, including the calcium signaling, wnt signaling pathway, focal adhesion, and cytokine-cytokine receptor interaction pathways. Results of the present study indicate gene expression differences in the ovarian tissues of relatively greater and lesser egg producing chickens, and identified five important candidate genes related to egg production, which provided a theoretical basis for improving egg production of Jinghai Yellow Chickens.