Catalytic Synthesis of Ethyl Ester From Some Common Oils

Catalytic conversion of ethanol to fatty acid ethyl esters (FAEE) was carried out by homogeneous and heterogeneous transesterification of melon seed, shea butter and neem seed oils using NaOH, KOH and 5wt%CaO/Al2O3 catalyst systems respectively. Oil content of the seeds from n-hexane or hot water extract ranged from 25.0-33.3% and increased in the order melon seed< shea butter seed < neem seed. The heterogeneous catalyst maintained an optimal activity after 5 cycles of reusable applications and produced higher FAEE of 95.63% than 91.2% and 92.8% obtained with KOH and NaOH respectively. After purification by distillation of excess ethanol and neutralisation and separation of the homogeneous catalysts, the FAEE was subjected to qualitative analysis to determine its potential application as commercial biodiesel based on international specifications. With the exception of neem seed oil FAEE that shows high acid value and total ash content the esters could be used directly or as blend in diesel engines to give good performance. Key words: Ethyl ester, synthesis, catalytic activity, common oils, biodiesel potential

Chromium, Nickel and Zinc Levels from Canned and Non-Canned Beverages in Zaria, Kaduna state, Nigeria

Heavy metals (Chromium, Nickel and Zinc) were determined from both canned and non-canned beverages sold in Samaru, Zaria, Kaduna State, Nigeria. Concentration of Chromium was found to range from 0.528 - 1.509mg/L for canned and 0.176 - 1.358mg/L for non-canned beverages, Nickel concentration was found to range from 0.156 - 0.802mg/L for canned and 0.125 - 0.896mg/L for non-canned beverages while Zinc concentration was also found to range between 27.652 to 35.447mg/L for canned and 26.649 to 42.447mg/L for the non-canned beverages. All the samples studied have Chromium and Zinc concentrations exceeding the maximum concentration limit (MCL) as set by USEPA while 100% of the canned beverages exceeded the (MCL) for Nickel only 93.33% of the non-canned exceeded the Nickel MCL. Levels of the metals analysed exceeded the legislative safe limits set by both United States Environmental Protection Agency (USEPA) and Standard Organization of Nigeria (SON).Keywords: Chromium, Zinc, Nickel, Canned, Non-canned beverages

Oxamniquine resistance alleles are widespread in Old World Schistosoma mansoni and predate drug deployment

Do mutations required for adaptation occur de novo, or are they segregating within populations as standing genetic variation? This question is key to understanding adaptive change in nature, and has important practical consequences for the evolution of drug resistance. We provide evidence that alleles conferring resistance to oxamniquine (OXA), an antischistosomal drug, are widespread in natural parasite populations under minimal drug pressure and predate OXA deployment. OXA has been used since the 1970s to treat Schistosoma mansoni infections in the New World where S. mansoni established during the slave trade. Recessive loss-of-function mutations within a parasite sulfotransferase (SmSULT-OR) underlie resistance, and several verified resistance mutations, including a deletion (p.E142del), have been identified in the New World. Here we investigate sequence variation in SmSULT-OR in S. mansoni from the Old World, where OXA has seen minimal usage. We sequenced exomes of 204 S. mansoni parasites from West Africa, East Africa and the Middle East, and scored variants in SmSULT-OR and flanking regions. We identified 39 non-synonymous SNPs, 4 deletions, 1 duplication and 1 premature stop codon in the SmSULT-OR coding sequence, including one confirmed resistance deletion (p.E142del). We expressed recombinant proteins and used an in vitro OXA activation assay to functionally validate the OXA-resistance phenotype for four predicted OXA-resistance mutations. Three aspects of the data are of particular interest: (i) segregating OXA-resistance alleles are widespread in Old World populations (4.29–14.91% frequency), despite minimal OXA usage, (ii) two OXA-resistance mutations (p.W120R, p.N171IfsX28) are particularly common (>5%) in East African and Middle-Eastern populations, (iii) the p.E142del allele has identical flanking SNPs in both West Africa and Puerto Rico, suggesting that parasites bearing this allele colonized the New World during the slave trade and therefore predate OXA deployment. We conclude that standing variation for OXA resistance is widespread in S. mansoni