The Materials and methods section contained errors in the labeling of the compounds. The corrected text and image provided by the Authors appear below. The corrected figure is reproduced in color in the online version of this correction.
2.9 Determination of absolute configuration of natural 12-hydroxy stearic acid derivatives
2.9.1 Reduction of 8b and 8a
A mixture of 8b (300 mg, 0.57 mmol) and 12 mg of 5% Pd/C in MeOH (3 ml) were stirred under hydrogen atmosphere (1 atm) for 6h at room temperature. Ethyl acetate (50 mL) was added as dilute solvent, the mixture was filtered through Celite short column. The solvent was removed under reduced pressure; the residue was purified by column chromatography on silica-gel with CHCl3/EtOAc (15:1). After removed the solvent, the product was purified by using HPLC (KUSANO silica-gel column, 2.2 cmφ × 30 cmL, N = 976–11 205) to give 9a (210 mg, 70%).
The same procedure used for the reduction of 8b was adopted with 8a. A mixture of 8a (300 mg, 0.57 mmol) and 12 mg of 5% Pd/C in MeOH (3 ml) were stirred under hydrogen atmosphere (1 atm) for 8 h at room temperature afforded 9b (201 mg, 67%).
3.3 Synthesis of comparing derivatives from MαNP ester of acetylenic octadecanol
Comparing samples were derived from 8-a/8-b which have acetylenic MαNP esters by hydrogenation of triple bond. The reaction was carried out under hydrogen atmosphere (1 atm) on 5% Pd/C. The products are purified by HPLC with silica-gel glass column (2.2 cmφ × 30 cmL, hexane/EtyOAc□30/1). After reduction, saturated long chain ester 9-b (R,S)/9-a (R,R) with known absolute configuration were synthesized.