There are many kinds of sterols, which are widely distributed in organisms. For example, cholesterol is an important component of higher animal cells. Cholesterol esters formed with long-chain fatty acids are important components of plasma lipoproteins and cell membranes.
Extended data sterol information
A kind of cyclopentanophenanthrene derivatives fused by three hexane rings and one cyclopentane. In addition to the lack of bacteria, it also exists widely in cells and tissues of animals and plants.
Sterol has many different biological functions, such as being a component of cell membrane, constituting adrenocortical hormone and sex hormone. Many phytosterols also have strong pharmacological or toxicological effects, such as digitalis and ouabain, which can enhance myocardial contraction and are good medicines for treating heart failure. Plants contain β -sitosterol and yeast contains ergosterol.
Cholesterol is the most abundant sterol in animals, which can be converted into steroid hormones-progesterone, estradiol, testosterone, cortisol and aldosterone.
Many contraceptive drugs are derivatives of progesterone; Some testosterone analogues are promoters of protein biosynthesis in vivo. 7- dehydrocholesterol can be transformed into vitamin D3 (cholecalciferol) when irradiated by ultraviolet rays in the skin, and the latter can be transformed into a hormone-1,25- dihydroxy cholecalciferol which regulates calcium and phosphorus metabolism in the body.
Ecdysone, which causes insect molting, and brown toxin against staphylococcus are also sterols. Frog toxin secreted by young phyllodes can block the transmission of neuromuscular nerve impulses in a small amount. The metabolic end product of cholesterol in the body is bile acid, while other sterols are biotransformed to increase their polarity and excreted.
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