Steroid biosynthesis Steroidal glycoalkaloids

McCue, K. F., Shepherd, L. V. T., Allen, P. V, Maccree, M. M., Rockhold, D. R., Corsini, D. L., Davies, H. V, Belknap, W. R. (2005). Metabolic compensation of steroidal glycoalkaloid biosynthesis in transgenic potato tubers using reverse genetics to confirm the in vivo enzyme function of a steroidal alkaloid galactosyltransferase. Plant science, 168, 267-273. 

Plants synthesise a number of steroid substances from cycloartenol, including 4,4-drmethylsterols, 4-methylsterols and demethylsterols. Cycloartenol is a precursor of many other steroids that are aglycons of saponins, of steroidal glycoalkaloids and of other compounds. Lanosterol in animals is a precursor for the biosynthesis of the most important zoosterol cholesterol (3-114). An intermediate in the biosynthesis of cholesterol is 7-dehydrocholesterol, which is a precursor of vitamin D3 (see Section 5.3.1). Cholesterol in the body is used for the biosynthesis of steroid hormones and bile acids (3-126). 

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