Textbook - BIOLOGICAL CHEMISTRY - Hubsky Yu.I. - 2000

Chapter V. HORMONES IN THE SYSTEM OF INTERCELLULAR INTEGRATION OF BODY FUNCTIONS

CHAPTER 25. HORMONAL REGULATION OF METABOLISM AND CELLULAR BIOLOGICAL FUNCTIONS. III. HORMONES AND OTHER LIPID-DERIVED BIOREGULATORS

25.1. GENERAL CHARACTERISTICS OF STEROID HORMONES

Steroid Hormones are a broad group of biologically active derivatives of the hydrocarbon stane, which chemically represent substituted cyclopentanoperhydrophenanthrene:

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Depending on the Chemical Nature of the R₁, R₂, and R₃ radicals, steroid hormones are classified into several groups:

Based on this chemical nomenclature, steroid hormones are divided into the following groups:

1. The pregnane group (C₂₁-Steroids), which includes:

1.1. corticosteroids, which are differentiated by their biological activity into:

1.1.1. glucocorticoids;

1.1.2. mineralocorticoids;

1.2. progestogens.

2. The estrane group (C₁₈-steroids) — estrogens.

3. The androstane group (C₁₉-steroids) — androgens;

All of these groups of steroid hormones are synthesized in the body from a polycyclic alcohol — a C₂₇-Δ⁵-steroid — Cholesterol (see Chapter 16). The general pathway of steroid hormone Biosynthesis is shown in Fig. 25.1.

Fig. 25.1. Biosynthesis of steroid hormones from cholesterol.

A distinct class of physiologically active compounds of steroid origin is the group D Vitamins (D₂, D₃, and their derivatives). These compounds, exhibiting both hormonal and vitamin properties, are chemically C₂₇-steroids (see section 25.4 below).