The 17-ketosteroid epiandrosterone is a metabolite of testosterone precursor dehydroepiandrosterone (DHEA). Epiandrosterone have been considered to be merely inactive end product of DHEA, but may in fact be physiological effectors in their own right. It is formed in peripheral tissues, from which it is released into the circulation and is ultimately excreted in the urine. Epiandrosterone is only a weak androgen, but it is widely recognized to inhibit the pentose phosphate pathway and to decrease intracellular NADPH levels. Epiandrosterone may act as a L-type Ca2+ channel antagonist. Epiandrosterone mainly transformed into 17beta-hydroxylated derivatives, 7- or 16alpha-hydroxylated metabolites under NAD(P)H conditions, and 5alpha-androstane-3,17-dione under NAD(P)+ conditions. Epiandrosterone is used as an anabolic agent (dietary supplement, a precursor to dihydrotestosterone) to increase strength, muscle hardness and also improves libido.

Biopterin (also known as L-erythro-biopterin or 6-Biopterin) is an oxidation product of tetrahydrobiopterin. Bioptrrin is an endogenous enzyme cofactor and its accumulation serves as markers of Parkinson's disease, Hyperphenylalaninemia and in addition, it can serve as a non-invasive biomarker for cancer.

Hypoxanthine is a naturally occurring purine derivative and a reaction intermediate in the metabolism of adenosine and in the formation of nucleic acids by the salvage pathway. Hypoxanthine is a necessary additive in the certain cell, bacteria, and parasite cultures as a substrate and nitrogen source. For example, it is commonly a required reagent in malaria parasite cultures, since Plasmodium falciparum requires a source of hypoxanthine for nucleic acid synthesis and energy metabolism.

Stigmastanol is a plant lipid molecule that resembles cholesterol in structure. It inhibits cholesterol absorption. Sitostanol powder (1 g) reduced cholesterol absorption by only 11.3 /- 7.4% (P = 0.2), confirming in vitro data showing poor solubility of sitostanol powder in artificial bile. In contrast, sitostanol in lecithin micelles reduced cholesterol absorption by 36.7 /- 4.2% (P = 0.003) at a dose of 700 mg and by 34.4 /- 5.8% (P = 0.01) at a dose of 300 mg. Stigmasterol, which is used for the synthesis of progesterone and vitamin D3 is a potential anti-inflammatory compound. Its action is mediated by the inhibition of several pro-inflammatory and matrix degradation mediators involved in osteoarthritis-induced cartilage degradation.

Histamine is a depressor amine derived by enzymatic decarboxylation of histidine. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and a centrally acting neurotransmitter. Phosphate salt of jistamine was used as a diagnostic aid for evaluation of gastric acid secretory function. In addition, this compound is used as a positive control in evaluation of allergenic (immediate hypersensitivity or "Type I") skin testing. In addition, histamine is being studied for treatment of multiple sclerosis. It was approved, that histamine physiological functions are mediated by four 7-transmembrane G protein-coupled receptors (H1R, H2R, H3R, H4R) that are all targets of pharmacological intervention. The receptors display molecular heterogeneity and constitutive activity. H1R antagonists are long known antiallergic and sedating drugs, whereas the H2R led to the development of H2R-antagonists that revolutionized stomach ulcer treatment. The H3R is an auto receptor and heteroreceptor providing negative feedback on histaminergic and inhibition on other neurons. The H4R occurs on immuncompetent cells and the development of anti-inflammatory drugs is anticipated.