Lipase‐catalyzed methanolysis of triricinolein in organic solvent to produce 1,2(2,3)‐diricinolein

Abstract

The objective of this study was to find the optimal parameters for lipase-catalyzed methanolysis of triricinolein to produce 1,2(2,3)-diricinolein. Four different immobilized lipases were tested, Candida antarctica type B (CALB), Rhizomucor miehei (RML), Pseudomonas cepacia (PCL), and Penicillium roquefortii (PRL). n-Hexane and diisopropyl ether (DIPE) were examined as reaction media at three different water activities (a(w)), 0.11, 0.53, and 0.97. The consumption of triricinolein and the formation of 1,2(2,3)-diricinolein, methyl ricinoleate, and ricinoleic acid were followed for up to 48 h. PRL gave the highest yield of 1,2(2,3)-diricinolein. Moreover, this lipase showed the highest specificity for the studied reaction, i.e., high selectivity for the reaction with triricinolein but low for 1,2(2,3)-diricinolein. Recoveries of 93 and 88% DAG were obtained using PRL in DIPE at a(w) of 0.11 and 0.53, respectively. Further, NMR studies showed that a higher purity of the 1,2(2,3)-isomer vs. the 1,3-isomer was achieved at higher a(w) (88% at a(w) = 0.53), compared to lower a(w) (71% at a(w) = 0.11). The DAG obtained was acylated by the DAG acyltransferase from Arabidopsis thaliana. Therefore, this enzymatic product is a useful enzyme substrate for lipid biosynthesis. Accordingly, the use of PRL in DIPE at a(w) 0.53 is considered optimal for the synthesis of 1,2(2,3)-diricinolein from triricinolein.

Castor diacylglycerol acyltransferase type 1 (DGAT1) displays greater activity with diricinolein than Arabidopsis DGAT1

“…Dipalmitolein and diolein were obtained from Larodan Fine Chemicals (Malmo, Sweden) and diricinolein was prepared by lipase digestion of triricinolein obtained by HPLC as described (Turner et al, 2003). Preparation of yeast microsomes and DGAT assays were done as described (He et al, 2004a(He et al, , 2004b) using 1-[ 14 C]-oleoylCoA as the acyl donor.…”

Lipase Catalyzed Methanolysis of Tri-(12-Hydroxy Stearoyl)-Glycerol in Organic Solvents

“…The course of esterification was monitored by reverse phase HPLC as previously described [3]. The expected products of lipase reaction, i.e., HS, MHS-glycerol, DHSglycerol and THS-glycerol were analyzed by injection of 50μL of sample on a C 18 RP-HPLC column, using mobile phase of methanol (A) and methanol: water (90:10) (B).…”

“…Preparation of THS-glycerol for methanolysis reactions was carried out by combining the product from multiple reactions and isolating the THS-glycerol by preparative HPLC using a 250 × 15 mm Phenomenex Luna C 18 RP column, 5 micron particle size, from Phenomenex, (Torrance, CA) eluted according to Turner et al [3].…”

“…Additionally, by judicious use of solvent and lipase, we have been able to produce high yields of 1,2-diricinoleoyl diacylglycerol [3]. The 1,2-diricinoleoyl DG was especially useful in identifying the activity of the diacylglycerol acyltransferase from castor seed [4].…”

Lipase‐catalyzed esterification of 2‐monoricinolein for 1,2(2,3)‐diricinolein synthesis

“…In previous work, we described how to produce 1,2(2,3)-diricinolein from triricinolein by methanolysis using Penicillium roquefortii lipase (5). However, to further characterize the RcDGAT, it would be helpful to have a source of radiolabeled 1,2-diricinolein to broaden our understanding of the RcDGAT substrate specificity.…”