The antibiotic anthelmycin was first isolated by Hamill and Hoehn from culture filtrates of Streptomyces longissimus. Anthelmycin (hikizimycin) has also been isolated from the fermentation broth of Streptomyces sp., strain A-5 which was obtained from a soil sample collected at the Hikizi river-side, Kanagawa Prefecture, Japan, by Uchida K. et al. Anthelmycin (hikizimycin) is active against fungi, especially phytopathogenic fungi. The drug inhibits the growth of a number of prokaryotic and eukaryotic organisms and also has antihelminthic activity. Anthelmycin inhibits protein synthesis on both pro- and eukaryotic ribosomes by preventing the peptide bond-forming reaction. The drug is structurally similar to certain other 4-aminohexosyl cytosine antibiotics including blasticidin S, gougerotin, amicetin and bamicetin although unlike these compounds anthelmycin lacks an aminoacyl moiety. It is proposed that anthelmycin inhibits the ribosomal peptidyl transferase centre by associating with a site that overlaps the (related) ribosomal receptor site(s) for the other four inhibitors.

Oleandrin is a toxic cardiac glycoside found in oleander (Nerium oleander L.). Along with neandrin it is primarily responsible for the toxicity of the sap of oleander. Oleandrin has been used for many years in China and Russia for its properties as a cardiac glycoside, for both suicidal and therapeutic purposes as in treatment of cardiac insufficiency. Because of its properties as a cardiac glycoside, oleandrin interferes in some essential processes within the cell, the most important of these being the inhibition of the Na-K ATPase. This protein enables the cell to exchange the cations Na+ and K+ between the intercellular and extracellular spaces by which, for instance, electronic signaling is made possible in nerve cells. Oleandrin binds to specific amino acids in the protein, causing it to lose its function. After depolarization of the cell in which Na+ flows into the cell, the Na+ cannot be transported back into the extracellular membrane, causing the sodium gradient to disappear. This gradient is the driving force for other transport proteins, such as the sodium-calcium exchanger, which plays an important role in cardiomyocytes. To make muscle contraction possible, a calcium influx from the extracellular fluid into the cell is crucial. After the muscle contraction, the calcium is normally pumped out of the cell and exchanged for sodium. When the sodium gradient is depleted, calcium cannot be pumped back and, as a consequence, accumulates in the cardiomyocyte. As a result of the high calcium concentration, actin and myosin filaments will bind stronger, unable to relax properly to make a new contraction possible. This may result in cardiac arrhythmias, in the worst case decreasing cardiac output and causing a shortage in oxygen supply in vital tissues. Apart from being a potent toxic compound, it may also be used in therapeutic ways. Both oleandrin and oleandrigenin, as well as their relatives, may be able to inhibit proliferation of tumor cells and stimulate their apoptosis as a result of the high concentration of intracellular calcium. In addition, it inhibits excretion of fibroblast growth factor 2 through membrane interaction and through inhibition of the Na,K-ATPase pump. However, there are no results from clinical testing on humans that support any use as a cancer treatment. Oleandrin has been reported to be lethal, but exact dosages are not fully documented. The fatal blood concentration of oleandrin has been estimated for humans to be approximately 20 ng/ml in decreased blood by extrapolation of intoxication symptoms. Symptoms present in poisoned animals include bloody diarrhea and colic, the latter especially in horses. Because the leaf itself is quite bitter, only starving animals will be likely to eat the plant. The lethal dosage for animals is estimated to be about 0.5 mg/kg.

Sepranolone (UC1010) is a GABA-A modulating steroid antagonist (GAMSA) and does not antagonize the effect of GABA itself or other GABAA agonists like benzodiazepines and barbiturates. The interaction of neuroactive steroids (i.e., allopregnanolone and Sepranolone) with GABA-A receptor is particularly important in mood disorders. For example, allopregnanolone administration decreased saccadic eye velocity in healthy female volunteers and induced sedation and these effects were diminished by simultaneous sepranolone administration. Thus, allopregnanolone effects are antagonized by its isomer sepranolone. UC1010 reduces symptom severity and impairment significantly more efficiently than placebo in women with a well-defined, pure premenstrual dysphoric disorder. No severe adverse events were reported during the UC1010 treatment and safety parameters (vital signs and blood chemistry) remained normal during the study. It was revealed also that increases in ring A-reduced progesterone metabolites, particularly Sepranolone, are associated with chronic fatigue syndrome.

Dideoxyadenosine (2′,3′-dideoxyadenosine) is a prodrug form of didanosine (2',3'-dideoxyinosine), a nucleoside reverse transcriptase inhibitor analog of adenosine. 2',3'-Dideoxyadenosine and 2',3'-dideoxyinosine were shown to be equally effective in the inhibition of HIV proliferation in human T cells. Dideoxyadenosine competitively inhibits adenylyl cyclase, thereby reducing levels of cyclic adenosine monophosphate (cAMP). By inhibiting cAMP-mediated gene activation in tumor cells, this agent may retard tumor cell proliferation. 2',3'-dideoxyadenosine inhibits retroviral DNA synthesis and mRNA expression in T cells exposed to the virus that causes acquired immunodeficiency syndrome, and affords such cells long-term protection in vitro under conditions of substantial viral excess. 2',3'-dideoxyadenosine appears to completely block reverse transcription from viral RNA to viral DNA. 2',3'-dideoxyadenosine was also shown not only to possess antibacterial activity in vitro against a variety of Enterobacteriaceae, but also to be effective in vivo, dideoxyadenosine was active in experimental mouse infections by the oral route against 5 Salmonella strains, 2 of 3 Arizona strains, 5 of 7 Citrobacter strains, 3 of 8 Klebsiella strains, 3 of 5 Escherichia strains, 1 of 3 Shigella strains, and 3 of 15 Serratia strains at concentrations generally well below the toxic level.

Curcumol is one of the major components of the essential oil of Rhizome Curcumae with the structure of sesquiterpenoid hemiketal. It exhibits characteristics such as antitumor, ant proliferation, anti-inflammatory, anti-hepatic fibrosis, antioxidant, and antimicrobial activities with low cytotoxicity. Curcumol suppresses the Breast Cancer Cells, Colorectal Cancer Cell Line, lung adenocarcinoma cell lines and others. However, its effect and mechanisms against tumor metastasis are still unclear. Recently was discovered a preliminary mechanism the suppression of breast cancer cell metastasis by curcumol. This mechanism suggested the inhibition of MMP-9 via JNK1/2 and Akt (Ser473)-dependent NF-κB signaling pathways.

CNDAC (TAK-109) is an analog of the nucleoside deoxycytidine with potential antineoplastic activity. CNDAC is incorporated into DNA and induces single-strand breaks, which are converted into double-strand breaks (DSBs) when cells go through a second S phase. This results in the cell cycle arrest in the S and G2/M phases, DNA fragmentation, and tumor cell apoptosis. Sapacitabine, a prodrug of CNDAC, is being developed by the US biotechnology company Cyclacel for the treatment of hemalogical cancers and solid tumors.

Icometasone (CL09) is a synthetic glucocorticoid corticosteroid. It is a metabolite of Mometasone Furoate. The binding on human serum albumin was shown to be non saturable, suggesting that other proteins were involved in CL09 binding. This binding was demonstrated to be reversible. CL09 was extensively metabolized since no unchanged CL09 was recovered in bile or urine and at least nine metabolites have been detected. It was studied in Europe as an anti-asthmatic agent but investigation is discontinued.

Puerarin (7, 4’-dihydroxyisolavone-8-β-glucopyranoside) is an active isoflavone extracted from the roots of Pueraria lobata (Willd.) Ohwi. Puerarin is widely used in traditional Chinese medicine, and is clinically used in China for the treatment of coronary artery disease, heart failure, hypertension and myocardial infarction. It has been reported that puerarin had therapeutic effects on diabetes mellitus, arteriosclerosis and myocardial ischemia in animals. Puerarin demonstrated beta-adrenergic receptor blocking effect. On the other hand, puerarin stimulated alpha1-adrenoreceptor to increase glucose uptake into cultured C2C12 cells of mice. Puerarin has been investigated for the treatment (phase II clinical trials) of Alcohol Abuse, Rheumatoid Arthritis and Hypertension.

Gemcitabine elaidate is an ester of anticancer drug gemcitabine and elaidic fatty acid. The motivation to make an ester was to facilitate gemcitabine uptake and prolong retention in the cell. The drug is converted to parent compound gemcitabine both inside and outside the cell. Gemcitabine elaidate was developed by Clavis Pharma for treatment of solid tumors, including non-small cell lung cancer and pancreatic cancer, but its development was discontinued after product missed the primary endpoint in the Phase II LEAP trial to treat metastatic pancreatic cancer.