estra13510triene

Estra-1,3,5(10)-triene, also known as estrane or estra-1,3,5(10)-triene, is a polycyclic hydrocarbon that forms the core structure of estrogens. It consists of four fused rings: three six-membered carbocyclic rings (A, B, and C) and one five-membered carbocyclic ring (D). The "1,3,5(10)-triene" designation indicates the positions of three double bonds within the structure, specifically in the A ring, which is aromatic. This aromaticity of the A ring is a defining characteristic of the estrogen steroid skeleton.

The estrane structure is the fundamental building block upon which various estrogenic hormones are based. Modifications to this basic skeleton, such as the addition of hydroxyl groups at specific positions or alterations to the side chain at the D ring, result in different biologically active estrogens. For instance, estradiol, the most potent naturally occurring estrogen in humans, is estra-1,3,5(10)-triene-3,17β-diol.

While estrane itself does not possess significant estrogenic activity, its derivatives play crucial roles in the development and regulation of female reproductive systems and secondary sexual characteristics. They are also involved in various other physiological processes in both males and females. The study of the estrane skeleton is fundamental to understanding steroid chemistry and endocrinology.