Production and properties of 7,10,12‐trihydroxy‐8(E)‐octadecenoic acid from ricinoleic acid conversion by Pseudomonas aeruginosa

Abstract

AbstractThis study was undertaken to produce a novel antifungal compound, 7,10,12‐trihydroxy‐8(E)‐octadecenoic acid (7,10,12‐THOD), in large quantities for determining its properties by use of crude ricinoleic acid as converted by Pseudomonas aeruginosa NRRL B‐23260. A useful reactor process was developed by employing a unique aeration mechanism and a new agitation device. The aeration mechanism involved a filtered airflow constantly supplied from the top through two ports on the headplate at 220 mL/min and at varied rates as needed and regulated through a bottom sparger, to control foaming. The agitation device combined a marine impeller and an open turbine to overcome the early phase of oxygen depletion and enhance production yields. A yield of 40% was achieved after 77 h of reaction when down‐stream processing of the bioproduct was most suitable. 7,10,12‐THOD was crystallized from ethyl acetate extracts of the reactor broth following a sequential cooling process to −20 °C. The melting point of 7,10,12‐THOD was 94.5–95.0 °C. The 1H‐ and 13C‐NMR signals of all protons and carbons in the 2(E)‐ene‐1,4,6‐triol moiety of 7,10,12‐THOD were now assigned, also with the aid of various 2D techniques. 7,10,12‐THOD was found to exhibit a unique surface‐active property. This study provides basic information and process technology for potential new uses of 7,10,12‐THOD.