Campe sterol

Major flaxseed sterols are stigmasterol, camp sterol, and 5-5 avenasterol (Daun et al., 2003). Obtusifoliol, gramisterol, and citrostadienol constituted 45%, 22%, and 12%, respectively, of the total 4a-monomethylsterol in flaxseed (Kamm et al., 2001). Squalene content of flaxseed oil was reported as 4 mg/100 g oil, which was significantly lower than olive, corn, and rice bran oils. Squalene content is an intermediate compound of biosynthesis of plant sterols, which may have protective effects on lipid quality. Squalene could act as a peroxy radical scavengers in high polyunsaturated fatty acid oil (Dessi et al., 2002). 

Category Myri- stic (%) Linole- nic (%) Arachidic (%) Eico- senoic (%> Behenic Lignoceric (%) (%) trans-oleic isomers (%) linolenic isomers (%) Chole- sterol (%) Brassi- casterol3 (%) Campe- sterol (%) Stigma- sterol (%) P-Sito- sterol (%) Stigma- sterol (%) Total sterols (mg/kg) ... 

Figure 8-6. Hormonal regulation of cholesterol synthesis by reversible phosphorylation of HMG CoA reductase. Availability of mevalonic acid as the fundamental building block of the sterol ring system controls flux through the pathway that follows. cAMP, cyclic adenosine monophosphate HMG CoA, hydroxymethylglutary I CoA.

Brudioside A (= Ruscogenin tetrasaccharide) (sterol tetrasaccharide) Brodiaea californica (Liliaceae) [tuber] cAMP PDE (89)... 

Furastanol hexasaccharides (2, 3 4) (sterol saponins) Ipheion uniflorum (Liliaceae) [ bulb] cAMP PDE (145 412 983)... 

Schaeffer, A., Bronner, R., Benveniste, P. and Schaller, H. (2002) The ratio of campes-terol to sitosterol that modulates growth in Arabidopsis is controlled by sterol methyl-transferase 2 1. Plant., 25, 605-15. 

Haider, S.K., M. Fink, M.R. Waterman, and D. Rozman (2002). A cAMP-responsive element binding site is essential for sterol regulation of the human lanosterol 14a-demethylase gene (CYP51). Mo/. Endocrinol. 16, 1853—1863. 

The sterols (0.6%) are mainly )8-sitosterol, camp-esterol and stigmasterol. The triterpenes (0.04%) include cycloartenol, cycloartanol, 24-methylene-cycloartenol and probably a-amyrin (Fedeli et aL, 1966). 

A number of plants synthesize ecdysteroids and sequester them in much greater concentrations than do insects (Fig. 23.19). It is probable that these compounds serve as defensive systems in the plant much in the same way as juvenile hormone mimics. For activity, a cw-A,B-ring fusion, a 6-keto-7-ene group, a full sterol side chain with a 22/ -oxygen function, an oxygen function at C-3, and oxygen groups at C-14 and 2p are necessary. However, not all insects may respond in an identical manner (Camps, 1991). 

Brassicastarol, ergosta-S,22-dien-3p-ol a plant sterol (see Sterols), M, 398.69, [a]o -64°, m.p. 148 °C, first isolated form rapeseed (Brassica campes-tris) oil. 

Cholesterol, long considered to be an indicator of the presence of animal fat, also occurs in small amounts in plants (Table 3.52). Campe-, stigma-and sitosterol, which are predominant in the sterol fraction of some plant oils, are structurally related to cholesterol only the side chain on C-17 is changed. The following structural segments (only... 

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