Antitumour promoters

In star anise, the presence of a prenyl moiety in the phenylpropanoids plays an important role in antitumour-promoting activity. Hence, the prenylated phenylpropanoids might be valuable as a potential cancer chemopreventive agent (Padmashree et al., 2007). 

A wide range of biological activities has been described for triterpenes and nor-triterpene quinonemethides. These include anti-inflammatory, anti-hyperlipidemic, antitumour-promotion, hepatoprotective, anti-ulcer, anti-microbial and hypoglycemic activitiy, among others [16,35]. Among the compound mentioned previously in this review, antitumour-promotion, anti-inflammatory, inmunosuppressive, anti-tumour, insecticide and anti-AIDS activities were found and are described below. 

Paederia scandends Paederoside Cancer chcmopreventivc Active as inhibitor of Epstein-Barr virus activation and antitumour promoting activity. [76J... 

Antitumour activity has been reported for alkyltins, particularly dibutyltin. The effect in mouse skin initiation/promotion protocols showed dibutyltin inhibiting the promotion stage (Arakawa Wada,... 

Peroxy derivatives of steroids have been isolated from both marine and terrestrial sources. They are most commonly 5a, 8a-endoperoxides with variations in the side-chains. The ergosterol peroxide 102 is the most ubiquitous endoperoxide-containing natural product and is isolated from a large number of sources. Ergosterol peroxide 102 was found to have antitumour activity against breast cancer and carcinosarcoma cell lines. A number of other steroidal endoperoxides have been reported which differ in the nature of the side-chain. Compound 103 was found to be an inhibitor of tumour promotion in mouse studies . 

Being able to use HMPA to promote [1,4]-Brook rearrangements is at the heart of the versatility of 67 as an equivalent for the synthon 68.53 55 The first alkylation is followed by addition of the second electrophile in the presence of HMPA, allowing the construction of molecules such as 69, a spiroketal component of the spongistatin antitumour agents.54... 

The counterattack mechanism is often favoured by nonfunctioning, down-regulation or loss of the cancer cell Fas receptors. Moreover, it has been reported that treatment with antitumour dmgs promotes the induction of Fas ligands on the cancer cells. ... 

Hastie, C.J. and Cohen, P.T.W., Purification of protein phosphatase 4 catalytic subunit inhibition by the antitumour drug fostriecin and other tumour suppressors and promoters, FEES Lett., 431, 357, 1998. 

Evans, F.J., and S.E. Taylor Pro-inflammatory, tumour-promoting and antitumour diterpenes of the plant families Euphorbiaceae and Thymelaeaceae. Fortschritte Chem. Org. Naturst. 44, 1 (1984). 

---