steroid hormone biosynthetic pathway C19-steroid hormone biosynthetic pathway 2010-04-20T03:43:21Z Androgen biosynthesis PW:0000770 Those metabolic reactions involved in the synthesis of C19-steroid hormones. Pregnenolone, a C21 steroid derived from cholesterol, and progesterone, to which pregnenolone can be converted, provide the starting material for the C21, C19 and C18 steroid hormones. The C19 class is represented by androgens such as testosterone. VPetri androgen biosynthetic pathway androgen biosynthetic process pathway