15-Hydroxy-epern-8(20)-en-18-saeure

The naturally occurring polyether ionophore salinomycin was previously found to display promising anti-proliferative activity against bloodstream forms of Trypanosoma brucei. Here, we report the evaluation of 20-deoxysalinomycin, a naturally occurring homolog to salinomycin, for trypanocidal and cell swelling activity. The concentration of 20-deoxysalinomycin required to reduce the growth rate of bloodstream-form trypanosomes by 50% was determined to be 0.12 μM and found to be 8 times more trypanocidal than that of salinomycin. Moreover, 20-deoxysalinomycin and salinomycin displayed similar cytotoxic activity against human HL-60 cells. Measured as the ratio of cytotoxic to trypanocidal activity, 20-deoxysalinomycin thus exhibits a four-fold higher selectivity compared to salinomycin. The stronger trypanocidal activity of 20-deoxysalinomycin is attributed to an enhanced ability to induce cell swelling in trypanosomes. The findings support 20-deoxysalinomycin as a useful lead in the rational development of new and improved anti-trypanosomal drugs.

Micrometer-sized spherical composites based on 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (CL-20) with fluororubber (F2604), dioctyl sebacate (DOS), and polyvinyl butyral (PVB) were prepared by an electrospray method. After preparation, the morphology, chemical bonds, thermal decomposition properties, mechanical sensitivity, and explosion performance were characterized. The main explosive CL-20 transformed from ε-CL-20 to β-CL-20 after electrospray preparation. With an insensitive additive mass ratio of 5 wt %, the CL-20/F2604 composite had the highest maximum peak exothermic temperature and the lowest mechanical sensitivity. The explosion pressures of the composites with the same mass ratio of additives decreased in the order CL-20/F2604 > CL-20/PVB > CL-20/DOS and were lower than that of raw CL-20.

The effect of temperature and light intensity on the polar lipidome of endophytic brown algae Streblonema corymbiferum and Streblonema sp. in vitro was investigated. More than 460 molecular species have been identified in four glycoglycerolipids classes, five phosphoglycerolipids classes and one betaine lipid class. The lipids glucuronosyldiacylglycerol and diacylglyceryl-N,N,N-trimethyl-homoserine were found in the algae of the order Ectocarpales for the first time. A decrease in cultivation temperature led to an increase in the unsaturation level in all classes of polar lipids. Thus, at low temperatures, the content of 18:4/18:4 monogalactosyldiacylglycerol (MGDG), 20:5/18:4 digalactosyldiacylglycerol (DGDG), 18:3/16:0 sulfoquinovosyldiacylglycerol (SQDG), 18:3/18:3 and 18:3/18:4 phosphatidylglycerol (PG), 20:4/20:5 and 20:5/20:5 phosphatidylethanolamine (PE), 14:0/20:5, 16:0/20:5 and 20:5/20:5 phosphatidylcholine (PC), 20:5/20:4 phosphatidylhydroxyethylglycine and 18:1/18:2 DGTS increased. At high temperatures, an increase in the content of chloroplast-derived MGDG, DGDG and PG was observed. Both low and high light intensities caused an increase in 20:5/18:3 MGDG and 18:3/16:1 PG. At low light intensity, the content of DGDG with fatty acid (FA) 18:3 increased, and at high light intensity, it was with FA 20:5. The molecular species composition of extraplastid lipids also showed a dependence on light intensity. Thus, the content of PC and PE species with C20-polyunsaturated FA at both sn-positions, 18:1/18:1 DGTS and 16:0/18:1 phosphatidylinositol increased. Low light intensity induced a significant increase in the content of chloroplast-derived 18:1/16:1 phosphatidylethanolamine.