Ferulic Acid Esters

Phytosterols have been demonstrated as being anti-cancer components in the diet (Awad and Fink 2000). Scientific studies indicate that phytosterols may offer profection against colon, breast and prostate cancers (Vanderhaeghe and Bouic, 2000). The possible mechanisms, as reported by these authors, include the effect of phytosterols on membrane structure and function and on the signal transduction pathways that regulate tumor growth and apoptosis. The rice bran derived phytosterol-cycloartenol-ferulic acid ester on the central nervous system has been studied by Hiraga et al. (1993). 

HIRAGA Y, NAKATA N, JIN H, ITO S, SATO R, YOSHIDA A, MORI T, OZEKI M, IKEDA Y (1993) Effect of the rice bran-derived ph)itosterol cycloartenol ferulic acid ester on the central nervous system. Arzneimittel-Forschung, 43(7) 715-21. 

How the aliphatic monomers are incorporated into the suberin polymer is not known. Presumably, activated co-hydroxy acids and dicarboxylic acids are ester-ified to the hydroxyl groups as found in cutin biosynthesis. The long chain fatty alcohols might be incorporated into suberin via esterification with phenylpro-panoic acids such as ferulic acid, followed by peroxidase-catalyzed polymerization of the phenolic derivative. This suggestion is based on the finding that ferulic acid esters of very long chain fatty alcohols are frequently found in sub-erin-associated waxes. The recently cloned hydroxycinnamoyl-CoA tyramine N-(hydroxycinnamoyl) transferase [77] may produce a tyramide derivative of the phenolic compound that may then be incorporated into the polymer by a peroxidase. The glycerol triester composed of a fatty acid, caffeic acid and a>-hydroxy acid found in the suberin associated wax [40] may also be incorporated into the polymer by a peroxidase. 

Cycloartenol ferulic acid ester Bran° ° Cycloeucalenol Sd oiP ° ... 

Determination of p-Hydroxycinnamic and Ferulic Acid Ester Units in Grass Lignins... 

Refined rice bran oil is an excellent salad oil and frying oil with high oxidative stability resulting from its high level of tocopherols and from the presence of the oryzanols (ferulic acid esters of sterols and triterpene alcohols). The oxidative stability of this oil is exploited in Good Fry Oil. This is a frying oil based on oleic-rich sunflower oil to which is added up to 6% of rice bran and/or sesame oil to confer high oxidative stability. Rice bran oil also finds several nonfood uses (45). 

Oryzanols are mixtures of ferulic acid esters of triterpene alcohols and plant sterols. Oryzanols were extracted from crude rice by column chromatography on a silica gel column using different volumes and ratios of hexane and di-Et ether. The fraction containing 18% oryzanol was further enriched by rechromatography, then 98% pure oryzanol was crystallized. 

Diesters hexadecan-7-yl p-coumarate Ferulic acid esters of Cu-Cjg primary alcohols 0 0 Ri-C-0CHj(CH2) CH2 0 C-R5 Diols C,-C , ... 

Rowe, J. W., C. L. Bower, and E. R. Wagner Extractives of jack pine bark Occurrence of cis- and /ran -pinosylvin dimethyl ether and ferulic acid esters. Phytochemistry 8, 235—241 (1969). 

Phenolic esters Ferulic acid esters of primary alcohols Cjg to C28 Commonly found in suberin-associated wax... 

The aliphatic components of suberin form polyester domains that are attached to the phenolics as indicated above (see Fig. 6.4.7). Activated cu-hydroxy acids and dicarboxylic acids are probably involved in the esterification as shown in cutin biosynthesis (232). It was proposed that the long-chain fatty alcohols found in suberin might be incorporated into the suberin polymer by peroxidase-catalyzed polymerization of phenylpropanoic acid esters of these alcohols (232), such as the ferulic acid esters of C18-C28 alcohols frequently found in suberin-as-sociated waxes (Table 6.4.2). 

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