9,16-dihydroxy-10-oxo-hexadecanoic acid, a novel component in citrus cutin
✍ Scribed by Karl E. Espelie; Wolfram Köller; P.E. Kolattukudy
- Publisher
- Elsevier Science
- Year
- 1983
- Tongue
- English
- Weight
- 718 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0009-3084
No coin nor oath required. For personal study only.
✦ Synopsis
When grapefruit cutin was treated with [SH] NaBH 4 and subsequently depolymerized with LiA1H~, a radioactive component which was more polar than 1,7,16-trihydroxyhexadecane was released. This component was identified by mass spectrometry as 1,7,8,16-tetrahydroxyhexadecane. Mass spectrometry of the tetraols derived from NaBD 4 reduction followed by LiAIH 4 depolymerization and from NaBH, reduction followed by LiAID 4 depolymerization indicated that these tetraols were derived from a dihydroxy C~e acid which contained a carbonyl group at C-10 or C-16. Periodate cleavage and permanganate oxidation of the labeled tetraol showed that the aH was located at C-10. Thus the cutin monomer from which the tetraol was generated was identified as 9,16-dihydroxy-10-oxo-hexadecanoate. This identity was confirmed by NMR analysis of the C t 6 tetraol obtained by LiAll-I 4 reduction of Citrus cutin which had been treated with NaBD 4. This dihydxoxyoxo-C16 acid was found to be a minor component of the fruit peel cutin from grapefruit (4.2%), lime (0.1%), lemon (1.2%) and orange (0.3%). 9,10,16-Trihyckoxyhexadecanoic acid was also identified as a minor component (0.1-1.9%) in these cutins.