Phenolic lipids occurrence

This great variety of types is summarised in the section on natural occurrence. Since the appearance of previous reviews on phenolic lipids... 

Table 1. Occurrence of monohydric phenolic lipids (cardanol type)...

Dihydric phenolic lipids are the most abundant phenolic lipids. They are of the cardol-or urushio 1-type, i.e. with hydroxyl groups in the metha position (1,3-dihydroxy) or in the ortho (1,2-dihydroxy) position respectively. Urushiol-type, dihydroxy phenolic lipids, are practically restricted to the Anacardiaceae family (Rhus genus) of poisonous plants. The most well-known are poison ivy, poison oak and the Indian marking nut. The sap from various plants belonging to Anacardiaceae from which Japanese, Chinese, Burmese, Formosan and Vietnamese lacs is one of the richest source of these phenols. The occurrence of dihydric phenolic lipid of the urushiol type is depicted in Table 3. 

Table 3. Occurrence of dihydric phenolic lipids of the urushiol type...

In the marine environment there has been the first reported occurrence of so-called antifouling (namely, anticrustaceous activity) by (15 0)-anacardic acid. Thus bioassay-directed fractionation of the dichloromethane extract from twigs of Ozoroa insignis containing the phenolic lipid, was used with larvae from Artemia salina as a model to investigate the activity [296]. 

Whether the occurrence of an enzyme in a particulate fraction really represents its in vivo location can be substantiated by the following properties (a) close binding to membrane lipids, cf. cyclopenase (D 8.4.2), which is a lipoprotein of the plasma membrane (b) cooperation with other enzymes, cf. the catalytic facilitation in the biosynthesis of cyanogenic glycosides, cinnamic and benzoic acids (A 3.1) and (c) in situ examination by cytochemical methods, cf. the localization of phenol oxidases (C 2.3.1), peroxidases (C 2.4) and thioglucosidases (D 9.4). 

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