Z-Chlorogenic acid better known as cis-5-caffeoylquinic acid is a cinnamate ester formed by condensation fo the carboxy group of cis-caffeic acid with the 5-hydroxy group of (+)-quinic acid. It is a naturally occurring isomer of Chlorogenic acid and can be extracted from Nerium indicum flowers, coffee plant, Purpurascen leaves, Artemisia pectinata, and tobacco. In some but not all extractions cis-5caffeoylquinic content is increased after UV exposure of plant or cells.

ABC-294640 is an orally bioavailable and selective sphingosine kinase-2 (SphK2) inhibitor with IC50 of approximately 60 uM. ABC-294640 inhibits SK2, a lipid kinase that catalyzes formation of the lipid signaling molecule sphingosine 1-phosphate (S1P). S1P promotes cancer growth, and proliferation and pathological inflammation, including TNFα signaling and other inflammatory cytokine production. Specifically, by inhibiting the SK2 enzyme, ABC-294640 blocks the synthesis of S1P which regulates fundamental biological processes such as cell proliferation, migration, immune cell trafficking and angiogenesis, and are also involved in immune-modulation and suppression of innate immune responses from T cells. Preliminary evidence suggests that because of its specificity for targeting SK2, rather than SK1, ABC-294640 may have a better therapeutic ratio than nonspecific sphingosine kinase inhibitors or those targeting only SK1. Oral administration of ABC-294640 to mice bearing mammary adenocarcinoma xenografts results in dose-dependent antitumor activity associated with depletion of S1P levels in the tumors and progressive tumor cell apoptosis. Therefore, this newly developed SK2 inhibitor provides an orally available drug candidate for the treatment of cancer and other diseases. ABC-294640 has completed multiple successful pre-clinical studies in inflammatory, GI, radioprotection and oncology models, as well as a Phase I clinical study in cancer patients with advanced solid tumors.

ZSTK474 is a new PI3K inhibitor with strong antitumor activity against human cancer xenografts without toxic effects in critical organs. Specifically, ZSTK474 is an ATP-competitive inhibitor of class I phosphatidylinositol 3 kinase isoforms. ZSTK474 blocks VEGF-induced cell migration and the tube formation in human umbilical vein endothelial cells (HUVECs), and inhibits the expression of HIF-1α and secretion of VEGF in RXF-631L cells, exhibiting potent in vitro antiangiogenic activity. ZSTK474 demonstrated prophylactic efficacy in a rat model of rheumatoid arthritis (RA) through inhibition of T cell and FLS functions.

Trichostatin A (TSA) was originally isolated as an antifungal antibiotic along with its fermentation congeners trichostatin B ((TSA)3-Fe) and the D-glucopyranosides trichostatin C and D. TSA inhibits HDAC in the low nanomolar range and is an inducer of histone hyperacetylation, both in vitro and in vivo. It inhibits all class I and II deacetylases to a similar extent in both tumor and non-tumor cells, although HDAC4 is slightly resistant when compared with HDAC1 and HDAC6. Class III HDAC is not affected by TSA. It has been shown that TSA dosedependently inhibits growth and induces apoptosis in a plethora of carcinoma cell lines in vitro. Recently, it was also found that TSA inhibits angiogenesis, which is important for the growth and metastasis of solid tumors, both in vivo and in vitro. In HT-29 colon carcinoma cells, a single dose of TSA induced transient hyperacetylation of histone H4 resulting in the induction of p21WAF1/Cip1 and inhibition of cellular proliferation at both the G1 and G2 phases of the cell cycle. Growth inhibition was associated with decreased cyclin D1 mRNA and cdk6 protein levels and increased cyclin D3 protein and p21WAF1/Cip1 mRNA levels. Cyclin D1 protein, cyclin D3 mRNA, cdk2 and cdk4 remained unaffected. In addition, TSA induced apoptosis by upregulating the expression of the pro-apoptotic genes ID1, ID2 and ID3, whereas the expression of the anti-apoptotic genes BclxL and Hsp27 was decreased In vivo, TSA induces differentiation and shows chemotherapeutic activity against N-methylnitrosureainduced rat mammary cancer without toxic side effects. TSA may also have therapeutic potential for the treatment of a variety of genetic and infectious diseases since silenced, transduced genes are reactivated probably due to structural changes of the chromatin on integrated viral sequences.

SNS-032 (formerly BMS-387032) is a potent, selective inhibitor of cyclin-dependent kinases (CDK). SNS-032 blocks the cell cycle via inhibition of CDKs 2 and 7, and transcription via inhibition of CDKs 7 and 9. SNS-032 was investigated for the treatment of solid tumors and hematologic malignancies (Phase I studies), however, its development was discontinued.

Dexniguldipine (B8509-035, (-)-(R)-niguldipine) is a new dihydropyridine derivative, that exerts selective antiproliferative activity in a variety of tumor models and, in addition, has a high potency in overcoming multidrug resistance. Dexniguldipine is ( - )-(R)-enantiomer of niguldipine, of which the ( )-(S)-enantiomer shows pronounced cardiovascular hypotensive activity due to its high affinity for the voltage-dependent Ca2 channel. As compared with the (S)-enantiomer, the (R)-enantiomer has a 40-fold lower affinity for the Ca 2 channel and, accordingly, only minimal hypotensive activity in animal pharmacology models. Dexniguldipine have shown antiproliferative activity in several tumor cell lines, but the concentrations necessary to inhibit growth have varied by several orders of magnitude between cell lines. Initial results of preclinical investigations for the evaluation of the mechanism of its antiproliferative activity demonstrate that dexniguldipine interferes with intracellular signal transduction by affecting phosphoinositol pathways, protein kinase C expression, and intracellular Ca 2 metabolism. In a series of human tumor xenografts in vitro, dexniguldipine demonstrated selective antiproliferative activity against several tumor types, e.g., melanoma and renal-cell carcinoma. Striking results were obtained in a hamster model, in which neuroendocrine lung tumors could be completely eradicated by 20 weeks of oral treatment with 32.5mg/kg dexniguldipine, whereas Clara-cell-type lung tumors were not affected. In in vitro studies, dexniguldipine has been found to bind to P-glycoprotein (P-gp) and to enhance the cytotoxicity of chemotherapeutic agents such as doxorubicin and etoposide in several cell lines The synergistic effect may well be associated with the reversal of multidrug resistance (MDR) related to the activity of P-gp. In the clinical therapy of cancer, resistance to many cytostatic drugs is a major cause of treatment failure. However, the high potency of dexniguldipine (about 10-fold as compared with that of verapamil in vitro) and its low cardiovascular activity provide the opportunity to achieve blood or tumor concentrations that might be high enough to overcome Mdr 1 resistance in patients without producing dose-limiting cardiovascular effects.

Swainsonine is an indolizidine alkaloid found in Australian Swainsona canescens, North American plants of the genera Astragalus and Oxytropis and also in the fungus Rhizoctonia leguminocola. It is competitive inhibitor of Golgi alpha-mannosidase II and lysosomal alpha-mannosidases. This compound has been reported to be a potent antiproliferative and immunomodulatory agent. However, no evidence of anti-tumor activity of swainsonine was seen in phase II clinical trial, in patients with locally advanced or metastatic renal cell carcinoma. Adverse events such as fatigue, nausea and diarrhea were common but generally mild. Swainsonine is locoweed toxin. Locoweed poisoning is seen throughout the world and annually costs the livestock industry millions of dollars. Swainsonine inhibits lysosomal alpha-mannosidase and Golgi mannosidase II. Poisoned animals are lethargic, anorexic, emaciated, and have neurologic signs that range from subtle apprehension to seizures.

Xanthohumol is a prenylated flavonoid most abundant in hops. It is found in beers and refreshment drinks. It can attenuate several factors of the metabolic syndrome. It has been reported to inhibit adipogenesis or increase cell apoptosis and therefore can be used in preventing obesity. Xanthohumol inhibited angiogenesis by suppressing NF-κB activity in pancreatic cancer. Xanthohumol may represent a novel therapeutic agent for the management of pancreatic cancer. Moreover, it is in phase I clinical trials for preventing many types of cancer. It has a range of other biological properties: antiviral, antimalarial, antibacterial and as an osteoporosis preventing agent.

Pepstatin is a pentapeptide of microbial origin. The peptide inhibits the acid proteases pepsin and cathepsin D and the pressor enzyme renin. Pepstatin was shown to provide long-lasting inhibition (3 to 6 days) of cathepsin D in vivo in non-tumor bearers particularly in spleen, liver, kidney, lung, and heart. Pepstatin may prove useful as "anticachexia" agent by decreasing proteolysis in muscle and other tissues. The in vivo pepstatin and IL-2 treatment decreased the T-cells and increased the natural killer-like LAK precursor cells, possibly also with an increase in its activity, which were further induced by in vitro IL-2 culture to generate an augmented LAK cell activity. This suggests the clinical potential of pepstatin in IL-2-related immunotherapy. In rats injected centrally with the specific cathepsin D inhibitor, pepstatin, the protease activity was inhibited up to 90% in most brain regions.

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.