Lipid metabolism: the potential targets for toxoplasmosis treatment.

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii (T. gondii). The current treatment for toxoplasmosis remains constrained due to the absence of pharmaceutical interventions. Thus, the pursuit of more efficient targets is of great importance. Lipid metabolism in T. gondii, including fatty acid metabolism, phospholipid metabolism, and neutral lipid metabolism, assumes a crucial function in T. gondii because those pathways are largely involved in the formation of the membranous structure and cellular processes such as division, invasion, egress, replication, and apoptosis. The inhibitors of T. gondii's lipid metabolism can directly lead to the disturbance of various lipid component levels and serious destruction of membrane structure, ultimately leading to the death of the parasites. In this review, the specific lipid metabolism pathways, correlative enzymes, and inhibitors of lipid metabolism of T. gondii are elaborated in detail to generate novel ideas for the development of anti-T. gondii drugs that target the parasites' lipid metabolism.

Monoterpenoid indole alkaloids from Alstonia scholaris and their Toxoplasma gondii inhibitory activity.

Nine previously unreported various types of monoterpenoid indole alkaloids, together with seven known analogues were isolated from the stem barks of Alstonia scholaris through a silica gel free methodology. The structures of 1-9 were elucidated by spectroscopic data analysis, electronic circular dichroism calculations, and single-crystal X-ray diffraction. Compound 1 is a modified echitamine-type alkaloid with a novel 6/5/5/7/6/6 hetero hexacyclic bridged ring system, and 8 and 9 exist as a zwitterion and trifluoroacetate salt, respectively. The anti-Toxoplasma activity of all isolates on infected Vero cells were evaluated, which revealed that compound 14 at 0.24 µM displayed potent activity. This study expanded the structural diversity of alkaloids of A. scholaris, and presented their potential application in anti-Toxoplasma drug development.

Deep soil microbial carbon metabolic function is important but often neglected: a study on the Songnen Plain reed wetland, Northeast China.

Soil microbial carbon metabolism is critical in wetland soil carbon cycling, and is also a research hotspot at present. However, most studies focus on the surface soil layer in the wetlands and the microorganisms associated with this layer. In this study, 0-75 cm soil profiles were collected from five widely separated reed wetlands in the Songnen Plain, which has a large number of middle-high latitude inland saline-sodic wetlands. The Biolog-ECO method was used to determine the carbon metabolic activity and functional diversity of soil microorganisms. The results showed that soil carbon metabolic activity decreased with increasing soil depth. The carbon metabolic activity of soil microorganisms in the 60-75 cm layer was approximately 57.41%-74.60% of that in the 0-15 cm layer. The soil microbial Shannon index and utilization rate of amines decreased with an increase in soil depth, while the Evenness index and utilization rate of polymers tended to increase with soil depth. Dissolved organic carbon (DOC) is the most important factor affecting microbial carbon source utilization preference, because microorganisms mainly obtain the carbon source from DOC. The result of the correlation analysis showed that the soil microbial carbon metabolic activity, Shannon index, and Evenness index significantly correlated with soil total carbon (TC), microbial biomass carbon (MBC), DOC, total nitrogen (TN), ammonium nitrogen (NH4 +-N), nitrate nitrogen (NO3 --N) contents, and electrical conductivity (EC). This study emphasized the important role of microbial carbon metabolic function in deep soil.

[Change in nitrogen availability of northern peatlands and its effect on carbon sink function]. / åŒ—æ–¹æ³¥ç‚­åœ°æ°®ç´ æœ‰æ•ˆæ€§çš„å˜åŒ–åŠå ¶å¯¹ç¢³æ±‡åŠŸèƒ½çš„å½±å“.

Northern peatlands are typical nitrogen-limited ecosystems, which are sensitive to global climate change and human activities. The increases of endogenous available nitrogen caused by climate warming and exogenous nitrogen input caused by human activities changed the nitrogen availability of northern peatlands, and would affect carbon and nitrogen cycling and carbon sink function of peatland. Here, we review the influence factors of carbon accumulation rate and carbon sink function in northern peatlands. The effects of nitrogen deposition, freezing and thawing, fire and other factors on nitrogen availability of northern peatlands were reviewed. The responses of plants and soil microorganisms to changes in nitrogen availability were elaborated from carbon fixation and carbon emission processes, respectively. The research related to carbon sink function of peat ecosystems under the influence of glo-bal change was prospected, aiming to help the implementation of the 'double carbon' goal.