Lipase‐catalyzed transesterification of trilinolein or trilinolenin with selected phenolic acids

Abstract

The enzymatic transesterification of selected phenolic acids with TAG, including trilinolein (TLA) and trilinolenin (TLNA), was investigated in an organic solvent medium. Maximal bioconversion of 66% was obtained with a dihydrocaffeic acid (DHCA) to TLA ratio of 1:2 after 5 d of reaction. Similarly, the highest bioconversion of 62% was obtained with a DHCA to TLNA ratio of 1:2, but after 12 d of reaction. However, a ratio of 1:4 DHCA/TLA decreased the bioconversion to 53%. Transesterification reactions of ferulic acid with both TAG, using a ratio of 1:2, resulted in low bioconversion of 16 and 14% with TLA and TLNA, respectively. The overall results indicated that bioconversion of phenolic MAG was higher than that of phenolic DAG. The structures of mono-and dilinoleyl dihydrocaffeate as well as those of mono-and dilinolenyl dihydrocaffeate were confirmed by LC-MS analyses. The phenolic lipids demonstrated moderate radical-scavenging activity. FIG. 2. HPLC chromatograms of the samples of the enzymatic transesterification reactions of DHCA with TLA (A and B) and trilinolenin (TLNA) (A′ and B′) monitored at 280 and 215 nm. Peak numbers were identified as follows: dihydrocaffeic acid, #1 and 1′; TLA, #7; TLNA, #7'; phenolic MAG, #2 and 2'; phenolic DAG, #5 and 5'; MAG, #3 and 3'; DAG, #6 and 6'; side reaction product, #4; and TLNA oxidation product, #8′. LIPASE-CATALYZED TRANSESTERIFICATION OF TRILINOLEIN AND TRILINOLENIN 105 JAOCS, Vol. 83, no. 2 (2006) FIG. 3. Atmospheric pressure chemical ionization MS analysis of monolinoleyl dihydrocaffeate (A), dilinoleyl dihydrocaffeate (B), monolinolenyl dihydrocaffeate (A'), and dilinolenyl dihydrocaffeate (B′). FIG. 4. Progress curves of the biosynthesis of phenolic MAG (I), phenolic DAG (I I), and total phenolic lipids (L) as well as the hydrolysis of TAG (L L) during the lipase-catalyzed transesterification of dihydrocaffeic acid with TLA (A) and TLNA (B).

Improved enzymatic production of phenolated acylglycerols through alkyl phenolate intermediates

“…The reason might be ascribed to the significant difference of substrate concentrations between two systems. The general concentration of DHCA in the system of Sabally et al (2006) was at 10 mM level, while the concentration of octyl dihydrocaffeate in the solvent-free system developed in this work was over 600 mM.…”

“…This was implemented successfully by Novozym 435-catalyzed esterification of DHCA with octanol in 2-butanone/hexane (1:3, v:v) binary solvent system according to the method of Sabally et al (2006). HPLC analysis showed the purity of the resulting product was 97% with minor unreacted DHCA.…”

“…The enzyme activity (Novozym 435) of solvent-free octyl dihydrocaffeate-tricaprylin interesterification system is over four times higher than the hexane-mediated system; remarkably, 190 times higher than solvent-free DHCA-tricaprylin system. Sabally et al (2006) reported lipasecatalyzed transesterification of DHCA with trilinolein and trilinolein in hexane/2-butanone (75:25, v/v), with the specific activity of around 0.5 μmol (g immobilized enzyme) -1 min -1 . If we neglect the difference between the two systems, in the protocol developed in this work the enzyme activity was >18 times higher than in hexane/2-butanone system.…”

“…However, their applications in oil-based food processing and cosmetic industries are limited due to their low solubility in hydrophobic media (Buisman et al, 1998;Figueroa-Espinoza and Villeneuve 2005). To improve the lipophilicity of phenolic acids, an alternative method is incorporation of phenolic acids into triacylglycerols through enzymatic reactions (Compton et al 2000;Sabally et al 2005Sabally et al , 2006Sabally et al , 2007Laszlo and Compton 2006). However, direct transesterification of phenolic acids with triacylglycerols is generally suffered from long reaction time and low efficiency (Figueroa-Espinoza and Villeneuve 2005;Compton et al 2000).…”

“…However, direct transesterification of phenolic acids with triacylglycerols is generally suffered from long reaction time and low efficiency (Figueroa-Espinoza and Villeneuve 2005;Compton et al 2000). Thus, many efforts, for example, through medium engineering to improve solubility of phenolic acids (Sabally et al 2006;Lue et al 2005), and through chemoenzymatic approach (Sun et al, 2009), have been made to improve the efficiency of related reactions.…”