N-acetylmuramic acid (MurNAc) is a bacterial cell wall component. Peptidoglycan, also called murein, is a polymer that consists of long glycan chains that are cross-linked via flexible peptide bridges to form a strong but elastic structure that protects the underlying protoplast from lysing due to the high internal osmotic pressure. The peptidoglycan is the only cell wall polymer common to both gram-negative and gram-positive bacteria. The glycan chain is built up of alternating, β-1,4-linked N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc) subunits. The chemistry of the glycan chains varies only slightly between different bacteria.

Perfluorooctane sulfonic acid (PFOS) is a global pollutant and an environmental toxicant, widely used as a fabric protector, serving as a stain repellant in drapery, carpets, and clothing. While its use in Europe, Canada, and the U.S. has been banned due to its human toxicity, it continues to be used in China and other developing countries as a global pollutant. However, epidemiologic evidence does not support a causal association between PFOS exposure and cancer risk in humans. However, in utero exposure to PFOS adversely affect the fetal synthesis and secretion of reproductive hormones (e.g., testosterone, estradiol, and inhibin B) in humans. Since the half-life of PFOS is relatively long, at 5.4-yr, even low-dose exposure to PFOS can accumulate in the body over an extended period of time. The mechanisms of PFOA -induced hepatic dysfunction are not completely understood but was shown, that PFOS induces their effects via targeting hepatocyte nuclear factor 4-alpha (HNF4α) and thus altered its conformation. In addition, some recent experiments in vitro revealed, that PFOS-induced male reproductive dysfunction can possibly be managed through an intervention on Akt1/2 expression.

5-Fluoroorotic acid is a fluorinated derivative of the pyrimidine precursor orotic acid. 5-Fluoroorotic acid exert considerable antitumor activity against transplanted tumors in rats and mice. 5-Fluoroorotate shows increased cytotoxicity on ovarian carcinoma cell lines following encapsulation in liposomes. 5-Fluoroorotic acid is used in vitro in the positive selection of genetically transformed yeast cells.