Lipophilic metabolite profiling of maize and sorghum seeds and seedlings, and their pest spotted stem borer larvae: A standardized GC-MS based approach.

In order to better understand the biochemical interactions and to identify new biomarkers for plant resistance against insects, we proposed a suitable lipophilic profiling method for insects and their host plants. The critical components of GC-MS based analysis are: sample amount, extraction, derivatization, temperature gradient, run time, and identification of peaks. For lipophilic metabolite profiling of maize and sorghum, and their insect pest, spotted stem borer larvae, we recommend 100 mg sample weight for seeds and insect samples (whole insect body), and 200 mg for seedlings. Maize and sorghum seeds required less time for fat extraction in comparison to their seedlings and the pest fed on these seedlings. GC-MS was standardized for better separation and intensity of peaks using different temperature gradients in the range of 180-300 C. A total of 48 lipophilic compounds encompassing various classes based on their functional groups such as fatty acids, fatty alcohols, hydrocarbons, sterols and terpenoids, vitamin derivative, etc. were separated in the seedlings (30), seeds (14), and the pest (26) in the retention time range of 3.22 to 29.41 min. This method could be useful to study nutritional aspects of different field crops in relation to various stresses apart from the analysis of lipophilic compounds for better understanding of insect-plant interactions.

Beneficial effects of Zingiber officinale Roscoe on fructose induced hyperlipidemia and hyperinsulinemia in rats.

Fructose supplementation produced cardinal features of Syndrome-X including significant elevations in seum cholesterol, triglyceride, glucose and insulin and also in body weight. While treatment with methanolic extract of dried rhizomes of Zingiber officinale produced a significant reduction in fructose induced elevation in lipid levels, bodyweight, hyperglycemia and hyperinsulinemia, treatment with ethyl acetate extract of Z officinale did not poduce any significant change in either of the last two parameters. However, it produced a significant reduction in elevated lipid levels and body weight The concentration of 6-gingerol was found to be higher in methanolic extract and less in ethyl acetate extract. The results suggest that the methanolic extract of Z officinale produces better effects as compared to ethyl acetate extract in fructose induced hyperlipidemia associated with insulin resistance. The extent of activity appears to be dependent on the concentration of 6-gingerol present in the extracts.

Bioquimica del ciclo evolutivo del triatoma infestans: VII. Composición de los lipidos de la superficie de la cuticula extraibles con hexano / Biochemistry of the developmental cycle of Triatoma infestans: VII. Lipid composition of the cuticle surface extracted with hexane

Los lípidos epicuticulares del insecto Triatoma infestans (vinchuca) fueron extraídos con hexano y fraccionados por cromatografía. Se detectaron alcocholes grasos hidrocarburos, ceras, triacilgliceroles, diacilgliceroles, ácidos grasos libres, colesterol, ésteres de colesterol y monoacilgliroles. Los alcoholes superiores e hidrocarburos constituín los componentes amyoritarios. La composición de los ácidos grasos, hidrocarburos y alcoholes fue estudiada por cromatografía gaseosa y espectrografía de masa. Los hidrocarburos fueron separados en lineales y ramificados. Ambos componentes estaban en proporciones similares y comprendían principalmente cadenas de número impar de carbonos de hasta 41 unidades. En los hidrocarburos lineales predominaron los de 27 a 33 carbonos. Se identificaron hidrocarburos monometil ramificados con la ramificación en posición iso, antelso e interna y dimetil-ramificados. Los alcoholes grasos fraccionados e identificados estaban constituidos por cadenas lineales de 16 a 34 carbonos, predominando los de 28 a 34 carbonos. Los ácidos grasos reconocidos y analizados en las diversas fracciones demostraron la presencia por un lado de un grupo principalmente constituido por ácidos de 16 y 18 carbonos, saturados y no saturados, y un grupo de ácidos saturados pares de m ayor longitud de cadena de 24 a 32 carbonos. La presencia de alcoholes, hidrocarburos y ceras constituidos por componentes principalmente saturados y alta longitud de cadena le conflere a la epicutícula una alta resistencia a los agentes químicos y físicos externos