Concentrations, Stability, and Isolation of the Furan Fatty Acid 9-(3-Methyl-5-pentylfuran-2-yl)-nonanoic Acid from Disposable Latex Gloves.

Because of their antioxidant properties, furan fatty acids (furan-FAs) are valuable minor compounds with a widespread occurrence in all living matter. Unfortunately, pure standards are not readily available, because they usually contribute only 1% to the lipid fraction. A known exception of this is the milky fluid of Hevea brasiliensis, commonly known as latex, in which the furan-FA 9-(3-methyl-5-pentylfuran-2-yl)-nonanoic acid (9M5) contributes about 90% to the triacylglycerides. In this study, we investigated the content of 9M5 in 30 different disposable latex gloves, which ranged from 0.7 to 8.2 mg/g of glove. The light degradability of 9M5 in latex gloves was investigated, and different amounts of 9M5 in disposable latex gloves were attributed to varying exposure time to light. Additionally, over 100 mg of the methyl or ethyl ester of 9M5 (purity of >98%) could be extracted from disposable latex gloves, employing cold extraction and silver ion chromatography. With this method, standards for the quantitation of furan-FAs are obtained easily and rapidly in all laboratories.

Isolation of a furan fatty acid from Hevea brasiliensis latex employing the combined use of pH-zone-refining and conventional countercurrent chromatography.

Furan fatty acids are valuable and bioactive minor fatty acids that usually contribute <0.1% to the fatty acid content of food samples. Their biological role still remains unclear as authentic furan fatty acid standards are not readily available and thorough experimental studies verifying the relevance of furan fatty acids are thus virtually impossible. An efficient protocol for the isolation of the furan fatty acid 9-(3-methyl-5-pentylfuran-2-yl)-nonanoic acid from hydrolyzed and centrifuged latex of Hevea brasiliensis was developed using countercurrent chromatography. A first run using pH-zone-refining countercurrent chromatography provided 48.4 mg of 9-(3-methyl-5-pentylfuran-2-yl)-nonanoic acid from 210 mg latex extract in a purity of 95%. The purity was increased to 99% by means of one second run in conventional countercurrent chromatography mode. The Structure and purity of 9-(3-methyl-5-pentylfuran-2-yl)-nonanoic acid were determined by gas chromatography coupled to mass spectrometry and (1)H and (13)C NMR spectroscopy.