Oestrone plants

Progesterone is synthesized from either cholesterol or alkylated plant sterols by a pathway similar to that in animals. Hydroxylation at C-20 and C-22 is a prerequisite for removal of the C-6 residue of the side chain (A, B, C, Fig. 16). The product pregnenolone is then reduced to progesterone (D, Fig. 16). Traces of oestrone, testosterone, deoxycorticosterone and closely related compounds have been found in plants but nothing is known of their biosynthesis. 

Terpenoids are also used as chemical messengers. If the communication is between different parts of the same organism, the messenger is referred to as a hormone. Examples of hormones are shown in Figure 1.8. Giberellic acid is a hormone used by plants to control their rate of growth. Testosterone and oestrone are mammalian sex hormones. Testosterone is a male hormone and oestrone, a female. 

A number of plant sterols have been reported to possess growth-regulating activity and developmental modification properties in plants (Heftman, 1975a, 1975b, Mandava, 1979). For example, -sitosterol (4) initiates flower buds in Chrysanthemum species exogenously applied lanosterol (15) (not a plant product) also stimulates flowering in these plants. Estrone (oestrone) (21) and related compounds are... 

The first phytooestrogen identified in plants was oestrone, found in small quantities in pahn and pahn kernel oils (obtained from oil pahn, Elaeis guineensis, Arecaceae) and pomegranate seeds Punica granatum, Punicaceae). 

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