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641.
M. Kamel 《African Journal of Ecology》2008,46(1):96-104
Three species, Zygophyllum album L., Z. coccineum L. and Z. simplex L., from family Zygophyllaceae were collected from two locations in Egypt to study their response to environmental conditions. Organic solutes (amino acids, soluble proteins and soluble sugars) and inorganic solutes (Na+, K+, Ca2+, Mg2+, Cl?, PO43? and SO42?) were estimated to study their role in osmotic adjustment under the effect of drought and salinity. The study showed that Z. coccineum is most tolerant for drought and salinity than Z. simplex. Z. coccineum was dependent on soluble proteins and soluble sugars, to increase its content of bound water, to undergo water deficit in desert. Z. simplex accumulated inorganic solutes more than Z. coccineum and less organic solutes. Amino acids content increased in Z. coccineum and Z. simplex survived in saline conditions to play a role in osmotic adjustment. Under the effect of salinity, all the studied species showed a tendency and high capacity to accumulate inorganic solutes. The main inorganic salutes were Ca2+, Mg2+ and Cl?. The role of Na+ was less than Ca2+ and Mg2+. Z. album and Z. simplex preferred Mg2+ more than Z. coccineum which preferred Ca2+. 相似文献
642.
epi-Androsterone 1 was converted into its hydrazone derivative through the reaction with hydrazine hydrate 80%. Hydrazonoandrostane derivative 2b reacted with hydrazonoyl halides in the presence of K2CO3 forming the corresponding hydrazopyridazinoandrostane derivatives 6a–d. The 3β-acetyl-17-hydrazonoandrostane derivative 2b reacted with a halogen reagent, benzoyl chloride, to form the non-cyclic 16-benzoylated hydrazone 9.On the other hand, compound 2b produced the corresponding pyridazinoandrostane derivatives 11 and 12 via its reaction with phenacyl bromide and chloroacetone respectively. Reaction of the hydrazono derivative 2b with benzaldehyde in the presence of acetic acid drops led to the formation of the benzylidenehydrazonoandrostane derivative 13. The product 14, phosphinom-ethylenehydrazonoandrostane was obtained by the reaction of the derivative 13 with trisdimethylaminophosphine in the presence of dry benzene. The reaction of compound 2b with phenyl isothiocyanate followed by boiling in chloroacetic acid or thioglycolic acid produced the pyrazoloandrostane derivatives 17 and 18 respectively. The biological activity of compounds 6a, 6d, 11, 12, and 15 was evaluated as inhibitor of growth in a human liver carcinoma cell line and doxorubicine was used for comparison. Compounds 15 and 12 showed a higher potency than the other tested compounds. 相似文献
643.
This paper examines the requirements for building database managementsystems and multi-database information resources to supportmolecular biology research. The paper profiles the most importantfeatures of 16 integrated resources and 102 databases relatedto molecular biology research. The aspects surveyed in thispaper include the nature of information in these databases,their sizes, update properties, cross-references, database managementsystem heterogeneity, geographical distribution, data quality,use of temporal information and level of interpretation. Thepaper also comments on the access patterns to these databases.Since not all these aspects were available for all databases,specific comparisons sometimes compare fewer than the full 102databases. Consequently, the same set of databases is not necessarilyalways being compared with respect to every aspect. The paperis organized primarily according to these comparison aspectsand ends with some concluding remarks. 相似文献