Progesterone formation

Ascorbic acid depleted from adrenal cortex or ovary on progesterone formation Niacin diphosphopyridine nucleotide (DPN) involved in progesterone synthesis... 

Scheme 5.30 CYPllAl-catalyzed conversion of ergosta-5-ene-ol and ergosta-5,22-diene-ol to pregnenolone in recombinant yeast- CYPllAl reaction details described in Section 5.2.1 and Scheme 5.4). Coexpression of 3p-hydroxysteroid dehydroge-nase/isomerase (3P-HSD) leads to progesterone formation.

Bioluminescence can also be used as the basis for immunoassay. For example, bacterial luciferase has been used in a co-immobilized system to detect and quantify progesterone using a competitive immunoassay format (34), and other luciferase-based immunoassays have been used to quantify insulin, digoxin, biotin, and other clinically important analytes (35). 

Oxidative degradations of aldehyde derived enamines with ozone (4) or sodium dichromate (485-487) have been applied to the formation of progesterone from 3-ketobisnor-4-cholenaldehyde. 

FIGURE 25.43 The steroid hormones are synthesized from cholesterol, with intermediate formation of pregnenolone and progesterone. Testosterone, the principal male sex hormone steroid, is a precursor to /3-estradiol. Cortisol, a glucocorticoid, and aldosterone, a mineralocorticoid, are also derived from progesterone. 

Koenig, HE, Schumacher, M, Ferzaz, B, DeThi, A, Ressouches, A, Gennoun, R, Jung-Tester, L, Robel, P, Akwa, Y and Baulieu, EE (1995) Progesterone S5mthesis and myelin formation by Schwann cells. Science 286 1500-1503. 

Figure 19.8 A brief summary of the pathways for formation and secretion of oestradiol and progesterone within the cells of the follicle. Cholesterol is taken up by thecal cells in a complex with low density lipoprotein. In the thecal cells, cholesterol is converted to testosterone which is released to be taken up by granulosa cells where it is converted into oestradiol. For synthesis of progesterone in the granulosa cells, cholesterol is synthesised de novo within the cells from acetyl-CoA. In the follicle the enzyme aromatase, which produces the aromab c ring in the female sex hormones, is restricted to the granulosa cells. The reacrions that are stimulated by LH and FSH increase synthesis and, therefore, secretion of testosterone and increased synthesis of oestrogens and progesterone.

An important transformation in steroid biochemistry is the conversion of pregnenolone into progesterone. Progesterone is a female sex hormone, a progestogen, but this reaction is also involved in the production of corticosteroids such as hydrocortisone and aldosterone. The reaction also occurs in plants, and features in the formation of cardioactive glycosides, such as digitoxin in foxglove. 

Congenital defects in the biosynthesis of steroid hormones can lead to severe developmental disturbances, in the adrenogenital syndrome (AGS), which is relatively common, there is usually a defect in 21-hydroxylase, which is needed for synthesis of cortisol and aldosterone from progesterone. Reduced synthesis of this hormone leads to increased formation of testosterone, resulting in masculin-ization of female fetuses. With early diagnosis, this condition can be avoided by providing the mother with hormone treatment before birth. 

---