Squaric acid is a dibasic organic acid and useful intermediate in a variety of synthetic reactions involving the synthesis of photosensitive squarylium dyes and inhibitors of protein tyrosine phosphatases. Medically, squaric acid dibutyl ester or dibutyl squarate derives from a squaric acid is used for the treatment of warts.

Fluoroacetic acid F-18 (18F-Fluoroacetate,18F-FAC) is an analog of acetate with a longer radioactive half-life (18F=110 min). Fluoroacetic acid F-18 was under investigation as a PET imaging agent. 18F-FAC was considered a promising alternative to 11C-ACE for positron tomographic imaging of prostate cancer, and possibly of other neoplasms with relatively low glucose use.

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.

2,2-DIMETHYLBUTYRIC ACID (HQK-1001) is an orally administered SCFAD (Short Chain Fatty Acid Derivative), which has shown an excellent safety profile and biologic effects on fetal hemoglobin induction and red blood cell production in the laboratory, relevant animal models, and in clinical trials carried out in healthy human subjects as well as patients with sickle cell disease and beta thalassemia. The compound has received Orphan Drug Designation in the United States and Europe for both sickle cell disease and beta thalassemia. HemaQuest Pharmaceuticals was developing HQK-1001 for the oral treatment of sickle cell anaemia and beta thalassaemia. HQK-1001 has been evaluated in phase II trials for beta thalassaemia and sickle cell anaemia.

D-aspartic acid is an essential amino acid and a key ingredient in various testosterone boosting anti-estrogen supplements. D-aspartic acid is not used to build proteins; instead, it plays a role in making and releasing hormones in the body. It is an endogenous NMDA receptor agonist with similar activity to the L-isomer. D-aspartic acid also enhances the release of luteinizing hormone (LH) and testosterone. This action is mediated in the pituitary by cGMP and in the testis by cAMP, which acts as the second messengers in the signal transduction in the pituitary and testes respectively. The pituitary and testis possess a D-Aspartate racemase, which provides the necessary production of this isomer.

Glutathione arsenoxide (GSAO) is a peptide trivalent arsenical that has potential anti-angiogenic capability, suggesting that it could be used for treatment in cancers where tumor metastasis relies on new blood vessel formation (angiogenesis). Endothelial cell proliferation drives new blood vessel formation. GSAO treatment causes a concentration-dependent increase in superoxide levels, ATP depletion, mitochondrial depolarization, and apoptosis in proliferating, but not endothelial cells. GSAO is able to block blood flow to solid tumors in mice, thereby inhibiting tumor growth in mice with no apparent toxicity at efficacious doses. Initial experiments have implicated GSAO in perturbing mitochondrial function. Other molecular effects of GSAO in human cells, for example on the phosphorylation of proteins, are still largely unknown. A phase I clinical trial has been terminated.

Iodohippuric acid I-125 (I-I25 Hippuran) is radioisotope that was used as a renogram probe in nefhrography in 1960s-1970s. It is an analog of I-131 labeled I(131) hippuran which has been recognized as the radiopharmaceutical standard for the measurement of effective renal plasma flow in subjects with renal failure but which use has been compromised by the suboptimal imaging characteristics of the 364-keV photon of 131I and the delivery of relatively high radiation doses to kidneys and thyroid in patients with impaired renal function. It was shown that radiation risk was rendered to a minimum with the use of the "cocktail" of 169U-EDTA and 125I-hippuran.