Steroid is the name for a very large group of natural and synthetic tetra cyclic carbohydrates with a common cyclopenta[a]phenanthrene skeleton. The rings are designated A, B, C, and D; however a unique numbering system is used.



The main part of steroids are tetra cyclic but some exceptions among the natural compounds are penta and even hexa cyclic (see saponines and steroid-alkaloids). Bufadienolides and cadenolides carry lactone rings as substituents. Steroids usually contain 21 - 30 carbon atoms and in case of 30 and more carbon atoms, they are called triterpenes. The thermodynamic more stable trans connection of cyclohexane rings A and B is preferred, and results in a flat and rigid molecular structure, hence the name steroid (Greek steros for rigid, solid:, and eides for designed). Cis connection is observed in some natural occurring groups of steroids like digitalis-glycosides, toad toxins and bile acids. Regardless the relatively simple ring structure we find a variety of compounds with remarkable biological activities, like toxins vitamin D, and hormones.

Important biological active steroids:


No other steroid is a more central point of discussion than cholesterol. It is the most abundant steroid in humans and important since many other steroids derive from it. An average adult has 200 g cholesterol. It is found in all body tissues and in especially large amounts in the neural system, because it is a major component of cell membranes and the myelin sheath, the essential protection of the neural cell axons. Mammals take up cholesterol with their diet; alternatively, it is biosynthesized from acetate. In combination with certain proteins, it aggregates to lipoproteins, which become insoluble. Those lipid rafts built up along the inside of arterial blood vessels causing the widespread disease atherosclerosis clogging of the vasculature, leading to heart attack and strokes.


Vitamin D
Vitamin D is the 7-dihydro derivative of cholesterol located in the skin. UV light induced bond break converts it to vitamin D3 an indispensable Ca2+ carrier. In earlier days especially in countries with weak winter sunlight infants suffered from rickets, a bone disease. Due to the deficiency of sun (UV) light vitamin B levels drop and not enough Ca2+ is carried to guarantee proper bone growth. Generations of toddlers got tortured with fish liver oil enriched with vitamin D (fish are adapted to synthesize vitamin D without UV light) that brought ease but nowadays, much to the relief of the children, synthetic vitamin D food supplements are provided.

Vitamin D

Hormones are chemical messengers secreted by endocrine gland and regulate biological processes. Corticosteroids are hormones produced by the cortex of the adrenal gland. They too are cholesterol derivatives. Cortisol is the most abundant corticosteroid but cortisone is the best known. Cortisone is a powerful remedy for treatment of chronic inflammation like rheumatoid arthritis, skin diseases like neurodermitis and most allergic responses, because it inhibits cell proliferation and suppresses the immune system. Cortisone has been celebrated as the wonder drug until grave side effects dampened the joy. However, it is still the most effective pharmaceutical against the mentioned diseases and therefore physicians cannot do without but it certainly requires proper dosage and careful usage.


Testosterone and estrogen are the male and female sex hormones, produced by the sex glands, testis and ovaries, respectively. Both are derivatives from cholesterol. They regulate sexual development in early adolescence and reproduction. Testosterone promotes secondary sex characteristics in young males as muscle growth, body hair and deepening of the voice. It is the precursor of estradiol, better known as estrogen, the main female sex hormone, which is the key substance in the female reproductive cycle and promotes female secondary sex characteristics. A separate synthesis leads from cholesterol to progesterone, another hormone involved in the menstrual cycle, suppressing premature ovulation during certain stages of the cycle and during pregnancy. Oral intake induces temporarily infertility and became the base of “The Pill”. New more tolerable synthetic substances like norethindrone have long replaced progesterone.

Bile acids
A large proportion of the body's cholesterol is degraded and oxidized to bile acids in the liver and stored the gall bladder. From there it is secreted into the intestines, usually in form of bile salts. Bile acids or better bile salts have a hydrophobic part and a hydrophilic part, one interacts with non-polar lipids the other with polar aqueous fluids (micelles). They can be considered as surfactants. Bile salts emulsify fats, which then are easier approached by lipases, and resorption in the intestine is facilitated. In biochemistry application of bile salts, helps to solve and isolate membrane bound proteins and enzymes. Cholic acid, its derivatives and salts are the principal bile acids found in the gall bladder.

Anabolic Steroids
A great temptation each price athlete comes across eventually is to take chemical substances to enforce body strength, stamina or what else his discipline requires. Testosterone as the principal male sex hormone, promotes also muscle growth. Increase in testosterone together with increase on amount of food will result in increase of the body's muscle mass. We call this process anabolic, since larger molecules are synthesized from smaller molecules. The reverse process would be catabolic, where larger molecules are degraded to smaller molecules. Testosterone's androgenic activity, however, makes it very poor anabolic steroid.
Research to find derivatives without masculinizing effects has led to the synthesis of androstenedione, methandrostenolone (Dianabol) and stanzolol. Athletes who to take any of those substances expose themselves to serious health risk, and provoke sterility, testicular atrophy and premature death from liver and heart failure.

Selection of Biosynth's Products
Cat.No. - Product Name
C-2940 - Chenodeoxycholic acid, sodium salt
C-5800 - 4-Cholesten-3-one
G-5300 - Glycocholic acid, sodium salt hydrate
G-8700 - Muristerone A
S-6500 - Sodium taurocholate
S-6560 - Sodium taurodeoxycholate
T-1150 - Taurocholic acid

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