Composition of the triacylglycerols of the phloem of Larix sibirica

The annual dynamics of the amount of acylglycerols in the phloem of the Siberian larch has been established. It has been shown that, depending on the phenological state of the wood their amount varies between 0.192 and 1.435%. The triacylglycerols of the phloem form the bulk of the acylglycerols of this tissue over the whole of the annual cycle. The stereovariety composition of the triacylglycerls of the phloem has been studied by the method of stereospecific analysis. It has been established that they have an asymmetric structure. The bulk of them contains acylglycerols in the molecules of which the sn-2 positions are acylated by unsaturated acids.Siberian Technological Institute, Krasnoyarsk. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 154–158, March–April, 1986.     

Heterocyclic compounds from 3-(4-phenyl) benzoyl propionic acid

3-(4-Phenyl) benzoyl propionic acid was used as the starting material for the synthesisof furanones (2), pyrrolinones (5), pyridazinones (7), benzoxazinones (8) and quinazolinones (9-11). The behaviour of the derivatives of furanones and benzoxazinones toward different nucleophiles is reported.     

几种乙酸铵离心法测定土壤阳离子交换量的方法探讨

乙酸铵离心交换法测定酸性和中性土壤阳离子交换量是经典方法,但此方法的蒸馏过程繁琐、时间长、效率低。本文引用纳氏试剂分光光度法测定土壤CEC值,并将结果与乙酸铵离心法常用的几种传统测定方法进行了实验对比和总结。通过对国家标准样品及实际土壤样品的CEC值测定,纳氏试剂比色法的精密度在2-4%之间,准确度与经典方法一致。与传统滴定法比较,取代了蒸馏的步骤,测定方法简单,干扰少,结果可靠,可操作性强。     

Oil in Louisiana's estuarine environments: A development model

Coastal erosion, accelerated by sea level rise, and subsidence are major Louisiana issues. With current sea-level-rise projections, coupled with the state's eroding barrier islands and coastal wetlands, the region's estuarine environments are in jeopardy of being lost, redefined, or permanently altered. As the coast erodes, Louisiana is endangered of losing valuable wetland's habitat. In addition, if the barrier islands disappear, the region's wetland-oriented oil and gas wells and associated infrastructure will be at risk to open Gulf conditions. If this should occur, each well, pipeline, and storage battery represents a potential environmental catastrophe.     

Photoredox mediated annelation of iododifluoromethylated alcohols with 1,1-diarylethylenes

A method for the synthesis of 3,3-difluorotetrahydrofurans from iododifluoromethylated alcohols and 1,1-diarylethylenes is described. The reaction is performed under irradiation with 400?nm light emitting diodes in the presence of a cationic iridium(III) photocatalyst, [Ir(ppy)₂(dtbbpy)]PF₆, substoichiometric amounts of triphenylphosphine and sodium trifluoroacetate as a base.     

Seasonal change in the essential oil ofLarix sibirica

Information is given on the qualitative and quantitative changes in the essential oil from the woody verdure of the Siberian larch. It has been established that during the vegetation period not only does the amount of essential oil in the woody verdure of the Siberian larch change but so also does the ratio of its individual components.