Steroids are chemical substances with biological activity. They’re made up of four rings organised in a certain molecular arrangement. Steroids have two major functions: they work as a key component of the cell membrane, altering the fluidity of the membrane, and they act as a hormone. These serve as a signalling molecule as well. Animals, plants, and fungus all contain hundreds of steroids. They’re also known as corticosteroids, and they’re anti-inflammatory drugs. Sterols like lanosterols and cycloartenol are used to make all of the steroids in the cells. These two sterols are produced through the cyclization of the triterpene squalene.
Steroids are made up of seventeen carbon atoms bound together in four fused rings, three of which are six-membered cyclohexane rings and one of which is a five-membered cyclopentane ring. The functional groups connected to the ring structure, as well as the oxidation state of the rings, distinguish the steroids from one another. Sterols are steroid derivatives with a hydroxyl group in the third position. These steroids can be drastically altered by altering the ring structure.
Hormones of Steroids
These are substances that have been synthesised to mimic hormones. Corticosteroids and sex steroids are two types of hormones that can be found in the human body. These classes can be varied by the different receptors connected to the ring structures, resulting in five different types of steroids:
- Glucocorticoids
- Mineralocorticoids
- Androgens
- Estrogens
- Progestogens
Steroid hormones are involved in the regulation of metabolism, the development of sexual characteristics, inflammation, immune system functions, and salt-water balance. Steroids are hormones that are produced naturally in the body as well as hormones that are produced intentionally to mimic the actions of natural hormones.
Steroids Nomenclature
Steran, also known as Gonane, is the most basic of all the steroids available and serves as the nucleus for all other steroids and sterols. It is made up of seventeen carbon atoms that are joined together by carbon-carbon bonds to form four fused rings in three-dimensional patterns. The skeleton of the steroids is made up of three cyclohexane rings. The skeleton is connected to the remaining five carbon atoms, which are joined to form a cyclopentane structure. The cholestane framework is formed when the eight carbon-side chains and two methyl groups are connected to this skeleton. When a hydrogen atom is linked to the carbon-5 atom in the structure, it causes a change in the side of the big planar ring structure, resulting in the two stereoisomeric forms of 5 and 5.
The following are some examples of steroid hormones:
- Cholic acid
- Lanosterol
- Medrogestone
- Testosterone
- Progesterone
All of these variations that occur to the Carbon-Carbon Bonds might vary the Steroids Framework in addition to the Expansions, Contractions, and Cleavages:
- They have the ability to change the bond ordering in the ring structure.
- The amount of methyl groups on the rings can also differ.
- The side chains and functional groups connected to the ring structure can differ.
- The groups linked to the ring structure and the side chains might have different configurations.
Steroids Come in a Variety of Forms
The functions and structure of steroids are classified as follows:
By Purpose These are categorised as follows:
1.Corticosteroids: It is divided into two subclasses:
- Glucocorticoids
- Mineralocorticoids
These steroids are used to inhibit the immune system, regulate blood pressure, and keep the water-electrolyte balance in check.
2.Sex Steroids: It aids in the maintenance of uterine cyclical changes as well as the development of secondary sexual characteristics.
By means of structure These are categorised as follows:
1)Intact Ring System-The chemical composition can be used to classify items in the intact ring system. Cholanes with 24 carbon atoms, estranes with 18 carbon atoms, and so on are examples.
2.)Rings that have been cleaved, expanded, and contracted:
- The biosynthetic or conceptual cleavage of the parent steroid rings produces secosteroids, a subclass of these steroidal substances.
- Biosynthetic steps produce norsteroids and homosteroids. It is made up of acyclic precursors with fewer or more ring atoms than the parent steroid framework, which undergo enzymatic ring expansion-contraction processes and ring closure.
Metabolism and Biosynthesis
The lanosterol or cycloartenol is the source of many steroids found in fungus, plants, and animals. The biosynthesis of steroids is an anabolic mechanism in which basic precursors are used to produce steroids. The animals, on the other hand, have their own biosynthetic pathway that provides a common target for the production of antibiotics and anti-infection medications. Statins are a cholesterol-lowering medication that targets steroid metabolism in humans. For the manufacture of steroids, humans and other animals use the mevalonate pathway. They use acetyl-CoA as a building block for DMAPP, which stands for dimethylallyl pyrophosphate, and IPP, which stands for isopentenyl pyrophosphate, in this process. These two combine in subsequent steps to generate GPP, which is extended into geranyl pyrophosphate, which is then synthesised into the steroid lanosterol, and the modifications made to these are referred to as steroidogenesis transformations.
1. The mevalonate pathway, also known as the HMG-CoA reductase pathway, begins with acetyl-CoA and concludes with IPP and DMAPP. The isoprene units are donated by the DMAPP and IPP, which are assembled and changed further to generate terpenes and isoprenoids. Squalene is made up of isoprene units that are linked together and folded into a ring to generate lanosterol, which is then transformed into cholesterol and ergosterol. Two kinds of medications are created as a result of this pathway: statins, which are used to lower cholesterol levels, and bisphosphonates, which are used to treat degenerative bone problems.
2. Steroidogenesis is the biological process through which steroids are produced from cholesterol, which is then transformed into other steroids.
- All other human steroids are derived from progesterone. All steroid-producing tissue in the human body must first convert cholesterol to pregnenolone. It occurs as a rate-limiting step in the production of steroids in the mitochondria.
- Aldosterone, testosterone, cortisol, and corticosterone are all produced by the adrenal cortex.
- During pregnancy, estriol is produced in the placenta, testosterone is produced in the testes, and estrone, progesterone, and estradiol are produced in the ovary.
- Estradiol is converted via the major pathway of DHEA-androstenedione-estrone or directly from testosterone.
Conclusion
Steroids are substances that are created naturally or intentionally to imitate the activities of particular hormones, according to the definition of steroids. Bodybuilders utilise anabolic drugs as steroids. These anabolic steroids even contain the Deca steroid. These can improve a muscle’s strength. Inflammatory diseases can be treated with certain steroids. There are several more advantages: bone density can be improved, red blood cell production can be improved, fat content in the body can be reduced, and so on.