4,4’-Diamino-2,2’-stilbenedisulfonic acid (also known as amsonic acid) is used in the synthesis of dyes and optical brighteners or fluorescent whitening agents. Amsonic acid possesses estrogenic activity, and thus provided a possible mechanistic explanation for the complaints of impotency in factory workers exposed to this compound. In the 2-year feed studies on rodents, there was no evidence of carcinogenic activity of amsonic acid, in male or female F344/N rats receiving 12,500 or 25,000 ppm. In addition, there was no evidence of carcinogenic activity of this compound in male or female B6C3F1 mice receiving 6,250 or 12,500 ppm.

Vaccenic acid (VA) (t11 octadecenoic acid) is a positional and geometric isomer of oleic acid (c9-octadecenoic acid), and is the predominant trans monoene in ruminant fats (50%–80% of total trans content). Dietary VA can be desaturated to cis-9,trans-11 conjugated linoleic acid (c9,t11-CLA) in ruminants, rodents, and humans. Hydrogenated plant oils are another source of VA in the diet, and it has been recently estimated that this source may contribute to about 13%–17% of total VA intake. In contrast to suggestions from the epidemiological studies, the majority of studies using cancer cell lines (Awad et al. 1995; Miller et al. 2003) or rodent tumors (Banni et al. 2001; Corl et al. 2003; Ip et al. 1999; Sauer et al. 2004) have demonstrated that VA reduces cell growth and (or) tumor metabolism. Animal and in vitro studies suggest that the anti-cancer properties of VA are due, in part, to the in vivo conversion of VA to c9,t11-CLA. However, several additional mechanisms for the anti-cancer effects of VA have been proposed, including changes in phosphatidylinositol hydrolysis, reduced proliferation, increased apoptosis, and inhibition of fatty acid uptake. In conclusion, although the epidemiological evidence of VA intake and cancer risk suggests a positive relationship, this is not supported by the few animal studies that have been performed. The majority of the studies suggest that any health benefit of VA may be conferred by in vivo mammalian conversion of VA to c9,t11-CLA. VA acts as a partial agonist to both peroxisome proliferator-activated receptors (PPAR)-α and PPAR-γ in vitro, with similar affinity compared to commonly known PPAR agonists. Hypolipidemic and antihypertrophic bioactivity of VA is potentially mediated via PPAR-/-dependent pathways.

Urocanic acid is a breakdown (deamination) product of histidine. In the liver, urocanic acid is an intermediate in the conversion of histidine to glutamic acid, whereas in the epidermis, it accumulates and may be both a UV protectant and an immunoregulator. Urocanic acid (UA) exists as a trans isomer (t-UA, approximately 30 mg/cm2) in the uppermost layer of the skin (stratum corneum). t-UA is formed as the cells of the second layer of skin become metabolically inactive. During this process, proteins and membranes degrade, histidine is released, and histidase (histidine ammonia lyase) catalyzes the deamination of histidine to form t-UA. t-UA accumulates in the epidermis until removal by either the monthly skin renewal cycle or sweat. Upon absorption of UV light, the naturally occurring t-UA isomerizes to its cis form, c-UA. Because DNA lesions (e. g. , pyrimidine dimers) in the lower epidermis can result from UV-B absorption, initial research proposed that t-UA acted as a natural sunscreen absorbing UV-B in the stratum corneum before the damaging rays could penetrate into lower epidermal zones. c-UA also suppresses contact hypersensitivity and delayed hypersensitivity, reduces the Langerhans cell count in the epidermis, prolongs skin-graft survival time, and affects natural killer cell activity. It has also been proposed that c-UA may mediate the transient alteration in immune surveillance resulting in immunosuppression induced after UV-irradiation, by interacting with immune cells locally and/or systemically to generate T cells with suppressor function.

Flavodic acid is a synthetic hydrosoluble derivative of natural flavonoids. It has been shown to reduce capiliary fragility and permeability. Sodium flavodate was marketed by the Italian pharmaceutical company Farmaceutici under tradename Pericel.

Antineoplaston (Phenylacetylglutamine) is the amino acid acetylation product of phenylacetate (or phenylbutyrate after beta-oxidation). The chemical structure of Antineoplaston AS2-5 corresponds to phenylacetylglutamine. Two synthetic derivatives of Antineoplaston A10 were named Antineoplaston AS2-1 and AS2-5. All antineoplaston formulations were submitted for Phase I clinical studies in advanced cancer patients. The treatment was free from significant side-effects and resulted in objective response in a number of advanced cancer cases. Antineoplastons are an experimental cancer therapy developed by S.R. Burzynski, MD, PhD. Chemically, antineoplastons are a mixture of amino acid derivatives, peptides, and amino acids found in human blood and urine. The developer originally isolated antineoplastons from human blood and later found the same peptides in urine. Urine was subsequently used because it was less expensive and easier to obtain. Since 1980, antineoplastons have been synthesized from commercially available chemicals at the Burzynski Research Institute. According to the developer, antineoplastons are part of a biochemical surveillance system in the body and work as "molecular switches." For the developer, cell differentiation is the key to cancer therapy. At the molecular level, abnormal cells that are potential cancer cells need to be "switched" to normal mode. Antineoplastons are the surveillance system that directs cancer cells into normal channels of differentiation. According to statements published by the developer, people with cancer lack this surveillance system because they do not have an adequate supply of antineoplastons.