The selectivity of Novozym 435, an immobilized Candida antarctica lipase B toward linoleic (LA), conjugated linoleic (CLA), and pinolenic acids (PLA) was investigated in the esterification of glycerol with an equimolar (27.3 mol% each) mixture of the fatty acids (FAs) in a solvent‐free system to prepare triacylglycerols (TAGs) with anti‐obesity effects. The maximal TAG content of 98.9 wt% was achieved under the following conditions: temperature, 70°C; reaction time, 24 h; glycerol‐to‐FA mixture molar ratio, 1:3; enzyme loading, 10 wt% of total substrates; vacuum level, 0.4 kPa. During the initial phase of the reaction, Novozym 435 showed pronounced selectivity in the order of PLA > CLA > LA; however, no significant difference in the selectivity of Novozym 435 toward the three FAs was observed after the reaction plateaued. Novozym 435 showed the significant selectivity toward PLA over CLA and LA at the sn‐2 position of TAGs throughout the reaction. The resulting TAGs had the same total content (∼27 mol% each) of the three FAs. However, the LA, CLA, and PLA contents at the sn‐2 position were 27.7, 24.7, and 30.3 mol%, respectively, indicating that unlike LA, CLA, and PLA were unevenly distributed on the glycerol backbone of the TAGs. Practical applications: CLA and PLA have received much attention because of their anti‐obesity effects. Structured TAGs containing both CLA and PLA not only maintain the health benefits of each but also may provide several advantages (e.g., enhanced oxidative stability, reduced incidence of off‐flavor) to both for food applications compared to the free FA forms. The selectivity of a lipase toward FAs used as substrates for the lipase‐catalyzed synthesis of structured TAGs affects the composition and positional distribution of FAs in the resulting structured TAGs. The present study reports a new finding about the selectivity of Novozym 435 toward LA, CLA, and PLA which are all C18‐unsaturated FAs, in the esterification of glycerol with the FAs to prepare structured TAGs containing both CLA and PLA. Novozym 435‐catalyzed esterification of glycerol with an equimolar mixture of linoleic, conjugated linoleic, and pinolenic acids.

The positional distribution pattern of fatty acids (FAs) in the triacylglycerols (TAGs) affects intestinal absorption of these FAs. The aim of this study was to compare lymphatic absorption of pinolenic acid (PLA) present in structured pinolenic TAG (SPT) where PLA was evenly distributed on the glycerol backbone, with absorption of pine nut oil (PNO) where PLA was predominantly positioned at the sn-3 position. SPT was prepared via the nonspecific lipase-catalyzed esterification of glycerol with free FA obtained from PNO. Lymphatic absorption of PLA from PNO and from SPT was compared in a rat model of lymphatic cannulation. Significantly (P < 0.05) greater amounts of PLA were detected in lymph collected for 8 h from an emulsion containing SPT (28.5 ± 0.7% dose) than from an emulsion containing PNO (26.2 ± 0.6% dose), thereby indicating that PLA present in SPT has a greater capacity for lymphatic absorption than PLA from PNO.

The genetic diversity of Schistosoma haematobium remains largely unstudied in comparison to that of Schistosoma mansoni. To characterize the extent of genetic diversity in S. haematobium among its definitive host (humans), we collected S. haematobium eggs from the urine of 73 infected schoolchildren at 5 primary schools in White Nile State, Sudan, and then performed a randomly amplified polymorphic DNA marker ITS2 by PCR-RFLP analysis. Among 73 S. haematobium egg-positive cases, 13 were selected based on the presence of the S. haematobium satellite markers A4 and B2 in their genomic DNA, and used for RFLP analysis. The 13 samples were subjected to an RFLP analysis of the S. haematobium ITS2 region; however, there was no variation in size among the fragments. Compared to the ITS2 sequences obtained for S. haematobium from Kenya, the nucleotide sequences of the ITS2 regions of S. haematobium from 4 areas in Sudan were consistent with those from Kenya (> 99%). In this study, we demonstrate for the first time that most of the S. haematobium population in Sudan consists of a pan-African S. haematobium genotype; however, we also report the discovery of Kenyan strain inflow into White Nile, Sudan.

c9,t11-CLA in the FFA fractions were 43.6 and 21.5 wt%, respectively, based on their initial weights in the CLA mixtures.Abstract The aim of this study was to selectively enrich t10,c12-conjugated linoleic acid (t10,c12-CLA) and c9,t11-CLA in commercial CLA mixtures using a combination of urea crystallization and lipase-catalyzed esterification. The objective of the urea fractionation is to remove saturated and monounsaturated fatty acids (FA) from the CLA mixtures. CLA-enriched free FA (FFA) mixtures containing 53.8 wt% t10,c12-CLA and 39.1 wt% c9,t11-CLA were produced from the CLA mixtures containing ~34 wt% each of the two CLA isomers by a urea crystallization using methanol and the urea-to-FA weight ratio of 2.5:1. The CLA-enriched FFA mixtures were partially esterified with dodecan-1-ol in a recirculating packed-bed reactor using an immobilized lipase from Candida rugosa to further enrich the t10,c12-CLA and c9,t11-CLA in an FFA fraction and an FA dodecyl ester fraction, respectively, under the optimal conditions, i.e., temperature, 20 °C; FA-to-dodecan-1-ol molar ratio, 1:1; water content, 2 wt% of total substrates; residence time, 5 min; and reaction time, 24 h (for t10,c12-CLA enrichment) and 12 h (for c9,t11-CLA enrichment). After the reaction, an FFA fraction with 72.6 wt% t10,c12-CLA was obtained. Another FFA fraction with 62.0 wt% c9,t11-CLA was recovered after the saponification of the FA dodecyl ester fraction. The yields of t10,c12-CLA and

No abstract