Fulvestrant is a drug treatment of hormone receptor-positive metastatic breast cancer in post-menopausal women with disease progression following anti-estrogen therapy. It is an estrogen receptor antagonist with no agonist effects, which works both by down-regulating and by degrading the estrogen receptor. Fulvestrant competitively and reversibly binds to estrogen receptors present in cancer cells and achieves its anti-estrogen effects through two separate mechanisms. First, fulvestrant binds to the receptors and downregulates them so that estrogen is no longer able to bind to these receptors. Second, fulvestrant degrades the estrogen receptors to which it is bound. Both of these mechanisms inhibit the growth of tamoxifen-resistant as well as estrogen-sensitive human breast cancer cell lines. Fulvestrant is used for the treatment of hormone receptor positive metastatic breast cancer in postmenopausal women with disease progression following anti-estrogen therapy. Fulvestrant is marketed under the trade name Faslodex, by AstraZeneca.

Exemestane is an oral steroidal aromatase inhibitor used in the adjuvant treatment of hormonally-responsive (also called hormone-receptor-positive, estrogen-responsive) breast cancer in postmenopausal women. It acts as a false substrate for the aromatase enzyme, and is processed to an intermediate that binds irreversibly to the active site of the enzyme causing its inactivation. Breast cancer cell growth may be estrogen-dependent. Aromatase (exemestane) is the principal enzyme that converts androgens to estrogens both in pre- and postmenopausal women. While the main source of estrogen (primarily estradiol) is the ovary in premenopausal women, the principal source of circulating estrogens in postmenopausal women is from conversion of adrenal and ovarian androgens (androstenedione and testosterone) to estrogens (estrone and estradiol) by the aromatase enzyme in peripheral tissues. Estrogen deprivation through aromatase inhibition is an effective and selective treatment for some postmenopausal patients with hormone-dependent breast cancer. Exemestane is an irreversible, steroidal aromatase inactivator, structurally related to the natural substrate androstenedione. It acts as a false substrate for the aromatase enzyme, and is processed to an intermediate that binds irreversibly to the active site of the enzyme causing its inactivation, an effect also known as "suicide inhibition". Exemestane significantly lowers circulating estrogen concentrations in postmenopausal women, but has no detectable effect on the adrenal biosynthesis of corticosteroids or aldosterone. This reduction in serum and tumor concentrations of estrogen delays tumor growth and disease progression. Exemestane has no effect on other enzymes involved in the steroidogenic pathway up to a concentration at least 600 times higher than that inhibiting the aromatase enzyme. Exemestane is marketed under the trade name Aromasin.

Zidovudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Zidovudine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated. Zidovudine, a structural analog of thymidine, is a prodrug that must be phosphorylated to its active 5′-triphosphate metabolite, zidovudine triphosphate (ZDV-TP). It inhibits the activity of HIV-1 reverse transcriptase (RT) via DNA chain termination after incorporation of the nucleotide analogue. It competes with the natural substrate dGTP and incorporates itself into viral DNA. It is also a weak inhibitor of cellular DNA polymerase α and γ. Zidovudine is used in combination with other antiretroviral agents for the treatment of human immunovirus (HIV) infections. Zidovudine is marketed as Retrovir.

Andrographolide, a diterpenoid, is known for its anti-inflammatory effects. It can be isolated from various plants of the genus Andrographis, commonly known as 'creat'. Andrographolide has been tested for its anti-inflammatory effects in various stressful conditions, such as ischemia, pyrogenesis, arthritis, hepatic or neural toxicity, carcinoma, and oxidative stress. Apart from its anti-inflammatory effects, andrographolide also exhibits immunomodulatory effects by effectively enhancing cytotoxic T cells, natural killer (NK) cells, phagocytosis, and antibody-dependent cell-mediated cytotoxicity (ADCC). The properties of andrographolide, such as its ability to induce apoptosis of cancer cells and inhibition of DTH, its anti-oxidative and cytoprotective effect, and its ability to enhance CTLs and NK cell activation makes it a potent antiviral agent. Andrographolide inhibited the growth of human breast, prostate, and hepatoma tumors. Andrographolide could be a potent anticancer agent when used in combination with other chemotherapeutic agents.

Friedelin is a natural compound with promising proprieties. On its own or with chemical modification it is possible to introduce relevant biological activities, e.g. anti-cancer, anti-aging and agrochemical. Its availability in significant amounts has been a major drawback on its regular use and in the pursuit of different applications. Cork and cork-derived materials (e.g. black condensate) are the most relevant sources of Friedelin in nature (up to 10% in concentration). Friedelin has being shown to possess marked antioxidant and liver protective effects. Friedelin has also being demonstrated to possess potent anti-inflammatory, analgesic and antipyretic activities.

Asparanin B is a steroidal saponin from the roots of Asparagus racemosus. It has being shown to exhibit significant anticancer activity in both in vitro and in vivo experimental models.

BMS-536924 is an ATP-competitive IGF-1R/IR inhibitor with IC50 of 100 nM/73 nM, modest activity for Mek, Fak, and Lck with very little activity for Akt1, MAPK1/2. BMS-536924 has been shown to inhibit the catalytic activity of IGF-1R and its down stream signaling components such as Akt and MAPK in cells; it also inhibits proliferation in a wide variety of human cancer cell lines including, colon, breast, lung, pancreas, prostate, sarcoma and multiple myeloma. In vivo, BMS-536924 inhibits tumor growth in an IGF-1R-dependent tumor model (IGF-1R Sal) as well as in a broad range of human tumor xenografts.

Beauvericin is a famous mycotoxin produced by many fungi, such as Beaveria bassiana and Fusarium spp. Beauvericin is a cyclic hexadepsipeptide (Figure 1) that belongs to the enniatin antibiotic family. It contains three D-hydroxyisovaleryl and three N-methylphenylalanyl residues in an alternating sequence. Beauvericin was first isolated from Beaveria bassiana, which is a common and commercial entomopathogenic mycoinsecticide. Beauvericin was one of the active constituents of B. bassiana and was confirmed to have antimicrobial and anti-tumor activities. Beauvericin has a strong antibacterial activity against human, animal and plant pathogenic bacteria with no selectively between Gram-positive and Gram-negative bacteria. The cytotoxicity of beauvericin to human tumor cells has been frequently reported.

Harpagide and harpagoside are two iridoid glycosides existing in many medicinal plants. They are believed to be the main bioactive compounds related to the anti-inflammatory efficacy of these plants. In vitro Harpagide has shown cytotoxic activity against tumor cell lines A431, HeLa and MCF7. Harpagide emerged as a leishmanicidal agent. Harpagide is common in nature and is known to possess anti-inflammatory activity. In addition, it has been shown that the hydrolysed products of harpagoside and harpagide have more pronounced anti-inflammatory activity when compared to the unhydrolysed compounds.

Digoxigenin is a 390.5 Da steroid expressed in heart, kidney, liver, adrenal gland, cerebral cortex, lung and placental tissues; Antibodies to Digoxigenin can be used to study tumor development. Bispecific antibodies (bsAbs) that bind to both tumor specific antigens on the cell surface and to haptens such as digoxigenin (Dig) can direct digoxigeninylated payloads to tumor cells. Digoxigenin is widely used as a method for generating non-radioactive probes, and is an alternative to biotinylation.