Change in the lipid composition of lichens in the spring period

The dynamics of the amount of total lipids, the ratio of the main classes of lipids, the amount of fatty acids, and the ratio of individual phospholipids in three epiphytic species of lichens from the Zhigulevsk reserve have been followed. It has been shown that all the classes of lipids of the lichens change to some degree or other in this period. The dynamics of the fatty acids has also confirmed a known rule: an increase in the amount of saturated and a decrease in the number of unsaturated fatty acids of the membranes with a rise in the temperature of the environment. This is the first time that the dynamics of the hydroxy acids have been followed.     

Fatty-acid and phospholipid composition of lichens of the Volga basin

The composition of the fatty acids and phospholipids of 16 species of lichens collected in the basin of the river Volga has been studied. The main phospholipid was phosphatidylcholine the amount of which ranged in the various species from 33.3 to 85.5% of the total phospholipids. Other phospholipids were also found: phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, and phosphatidylglycerol. The main fatty acids were the 16:0, 18:0, and 18:1 varieties. Institute of the Ecology of the Volga Basin, Russian Academy of Sciences, Tol'yatti. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 613–615, September–October, 1991.     

Fatty-acid and phospholipid composition of lichens of the Volga basin

The composition of the fatty acids and phospholipids of 16 species of lichens collected in the basin of the river Volga has been studied. The main phospholipid was phosphatidylcholine the amount of which ranged in the various species from 33.3 to 85.5% of the total phospholipids. Other phospholipids were also found: phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, and phosphatidylglycerol. The main fatty acids were the 16:0, 18:0, and 18:1 varieties.Institute of the Ecology of the Volga Basin, Russian Academy of Sciences, Tol'yatti. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 613–615, September–October, 1991.     

Analytical and statistical analysis of elemental composition of lichens

The elemental composition of lichens from remote southern South America regions has been studied with analytical and statistical techniques to determine if the values obtained reflect species, growth forms or habitat characteristics. The enrichment factors are calculated discriminated by species and collection site and compared with data available in the literature. The elemental concentrations are standardized and compared for different species. The information was statistically processed, a cluster analysis was performed using the three first principal axes of the PCA; the three groups formed are presented. Their relationship with the species, collection sites and the lichen growth forms are interpreted.     

Change in the mineral composition of phytates

The mineral composition of phytin has been studied as a function of the variety of the source of raw material and the possibility of its change during the process of isolation.All-Union Scientific-Research Chemical and Technological Institute of the Medicinal Industry, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 695–698, September–October, 1991.     

Change in the mineral composition of phytates

The mineral composition of phytin has been studied as a function of the variety of the source of raw material and the possibility of its change during the process of isolation. All-Union Scientific-Research Chemical and Technological Institute of the Medicinal Industry, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 695–698, September–October, 1991.     

The lipid composition of the Western Mediterranean aerosol

Summary Marine remote aerosol samples collected in a fixed station situated at 1100 m above sea level in Mallorca Island (Western Mediterranean) have been analyzed for lipids, both neutral and acidic, by capillary gas chromatography (GC) and GC coupled to mass spectrometry. Higher plant and algal compounds are predominant. The former encompass distributions of even numbered C22–C32 n-alkan-1-ols (8–21 ng/m³) and n-aldehydes, C25–C32 odd numbered n-alkanes (3–6 ng/m³), and n-nonacosan-10-ol, -sitosterol (0–0.09 ng/m³), dehydroabietic acid and triterpenols. The latter are constituted by even numbered C14–C18 fatty acids (0.6–30 ng/m³) and cholest-5-en-3-ol (0–0.86 ng/m³). Pyrolytic polycyclic aromatic hydrocarbons are also found (86–410 pg/m³) whereas direct petrogenic inputs are not significant.     

Elemental composition of lichens at Nahuel Huapi National Park,Patagonia, Argentina

Five species of epiphytic lichens were sampled from urban and periurban areas of Bariloche, a non industrial city located on the East side of the Nahuel Huapi National Park, North-Western Patagonia, Argentina, and from pristine areas of the Park. Each individual lichen was analyzed using Instrumental Neutron Activation Analysis. The results of the analysis showed high concentrations of lithophile elements, with very good correlations among them. The relative concentration of these elements in all lichen species is in good agreement with the elemental composition of sediments collected in the Park. Elemental concentrations which are not related to detritical inputs are also presented.     

Effect of lipid headgroup composition on the interaction between melittin and lipid bilayers

The effect of the lipid polar headgroup on melittin-phospholipid interaction was investigated by cryo-TEM, fluorescence spectroscopy, ellipsometry, circular dichroism, electrophoresis and photon correlation spectroscopy. In particular, focus was placed on the effect of the lipid polar headgroup on peptide adsorption to, and penetration into, the lipid bilayer, as well as on resulting colloidal stability effects for large unilamellar liposomes. The effect of phospholipid headgroup properties on melittin-bilayer interaction was addressed by comparing liposomes containing phosphatidylcholine, -acid, and -inositol at varying ionic strength. Increasing the bilayer negative charge leads to an increased liposome tolerance toward melittin which is due to an electrostatic arrest of melittin at the membrane interface. Balancing the electrostatic attraction between the melittin positive charges and the phospholipid negative charges through a hydration repulsion, caused by inositol, reduced this surface arrest and increased liposome susceptibility to the disruptive actions of melittin. Furthermore, melittin was demonstrated to induce liposome structural destabilization on a colloidal scale which coincided with leakage induction for both anionic and zwitterionic systems. The latter findings thus clearly show that coalescence, aggregation, and fragmentation contribute to melittin-induced liposome leakage, and that detailed molecular analyses of melittin pore formation are incomplete without considering also these colloidal aspects.     

Observation of inhomogeneity in the lipid composition of individual nanoscale liposomes

Liposomes, or vesicles, have been studied extensively both as models of biological membranes and as drug delivery vehicles. Typically it is assumed that all liposomes within the same preparation are identical. Here by employing pairs of fluorescently labeled lipids we demonstrated an up to 10-fold variation in the relative lipid composition of individual liposomes with diameters between 50 nm and 15 μm. Since the physicochemical properties of liposomes are directly linked to their composition, a direct consequence of compositional inhomogeneities is a polydispersity in the properties of the individual liposomes in an ensemble.     

Change in consistency and composition of trichloroethylene- and trichloroethane-treated asphalts

Solvent extraction of asphalt from pavement mixtures is a technique used to study the change in asphalt during service. Rheological measurements indicate that asphalts recovered from trichloroethylene or trichloroethane are markedly hardened. Compositional studies on asphaltic fractions reveal a notable decrease in saturates, naphthenes, H, N, Ni and V, and increase in polar aromatics and asphaltenes along with incorporation of Cl in all fractions. These structural changes are responsible for the hardening of the asphalt and are interpreted in terms of cyclization of saturates, aromatization of naphthenes, coupling of free radicals with neutral species to give a high content of asphaltenes, and in terms of loss of the relatively volatile Ni and V porphyrins during the extraction—recovery process.     

Salt-induced changes in lipid composition and ethanol tolerance inSaccharomyces cerevisiae

The effect of salt stress on lipid composition and its relationship with ethanol tolerance inSaccharomyces cerevisiae was studied. Amounts of phospholipids as well as that of sterols decreased, whereas that of protein and glycolipids increased with increasing salt concentration. Relative proportion of amino phospholipids (phosphatidylethanolamine and phosphatidylserine) decreased, whereas that of phosphatidylcholine showed a reverse trend. Cells grown under increasing salt concentration were more resistant to ethanol-induced leakage of UV-absorbing substances, an index of ethanol endurance. Results showed an overlap between osmotolerance and ethanol tolerance in this strain.     

Analysis of the effect of malaria on lipid composition of rhesus plasma

The phospholipid distribution and the ratio of cholesterol-to-cholesterol ester have been determined for plasmas isolated from normal, fasted and P. knowlesi-infected rhesus monkeys. Compared to normal plasmas, the infected plasmas show phospholipid patterns with slight increases in phosphatidylcholine and larger decreases in lysophosphatidylcholine. The cholesterol-to-cholesterol ester ratio is always less than one in normal plasmas and greater than one for infected plasmas. There are no differences between samples isolated from fasting and non-fasting animals for any of the constituents examined.     

潜指纹残留物中油脂的气相色谱分析

建立一种适于分析潜指纹残留物中油脂组成的简便快速、灵敏可靠的GC/FID分析方法。以V(正己烷)∶V(CH2Cl2)=1∶10为提取剂,HP-5毛细管色谱柱和氢火焰离子检测器进行分析。潜指纹残留物中油脂组成复杂,不同个体捺印所得样品组成之间既有共同之处,又有各自典型特征;暗处保存及自然光照条件下,油脂组成发生变化,油脂含量总体呈下降趋势,但部分物质含量呈波动性变化;两种老化方式下的变化趋势相似,但自然光照条件下油脂衰减速度较快,光照10天后的潜指纹残留物中仍可见含量丰富的油脂。方法灵敏度能够达到单枚指纹残留物检测要求。     

Investigation of mercury speciation in lichens.

Epiphytic lichens have long been considered to be reliable bioindicators of air pollution. In the present study only one lichen species, Hypogymnia physodes (L.) Nyl., was chosen; this species is very often used for biomonitoring in Europe. Total mercury and methylmercury were determined in lichens taken from various polluted and unpolluted locations in Slovenia, including a mercury mining area around Idrija. Additionally, total gaseous mercury in air was also determined at several sampling points.     

Influence of the degree of ripeness of cotton seeds on their lipid composition

The influence of the degree of ripeness of the seeds of the cotton plant on their lipid composition has been studied. It has been established that as the seeds ripen their lipid composition becomes simpler, and in the developing cotton seeds the biosynthesis of triglycerides takes place with the participation of the mono-and diacylglycerides as intermediates.     

Influence of the degree of ripeness of cotton seeds on their lipid composition

The influence of the degree of ripeness of the seeds of the cotton plant on their lipid composition has been studied. It has been established that as the seeds ripen their lipid composition becomes simpler, and in the developing cotton seeds the biosynthesis of triglycerides takes place with the participation of the mono-and diacylglycerides as intermediates.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 40–44, January–February, 1982.     

Influence of the temperature of cultivation on the lipid composition of the bacterium Yersinia pseudotuberculosis

Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Institute of Marine Biology, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 579–580, July–August, 1991.