Biological antitumor activity

Source Crotolariajuncea. Molecular formula Cig H25 N O5. Molecular weight 335.44. Melting point 232-3 deg C. Biological activity Antitumor. 

Source Calotropis procera. Molecular formula C29 H40 O 9. Molecular weight 532.69. Melting point 221 deg C. Biological activity Antitumor. 

Source Taxus brevifolia. Molecular formula C47H51 N O4. Molecular weight 853.99. Melting point 213-6 deg C. Biological activity Antitumor. 

BIOLOGICAL ACTIVITY Antitumor [8191] cytotoxic against leukaemia L 1210 cells [8191,8192]. 

The resorcinylic macrolides (also known as resordnylic add lactones or RALs) are a family of naturally occurring homologous macrolides. They are derived from polyketide biogenesis in different fungi and have been isolated from different fungal strains [12]. They have unique chemical structures and potent biological activities (antitumoral, antibiotic, and antimalarial activities) [13]. 

Several semisynthetic maytansinoids have been prepared by acylating the C-3 hydroxyl group of maytansinol. Some of these derivatives have antiprotozoal and antitumor activity similat to maytansine (104) and ansamitocin P-3 (127) (52,254). 3-Epimaytansinoids have been synthesized and were not biologically active (255). 

Biological Activity. The maytansinoids possess antitumor activity, particulady against P 388 lymphocytic leukemia, B 16 melanocarcinoma, and Lewis lung carcinoma. A number of semisynthetic esters of maytansinol have been prepared and exhibit good antileukemic activity (52,255). The maytansides lack antitumor activity, indicating that the ester at C-3 is a requirement for activity (50,52). The carbinolamide also appears to be necessary for... 

Since the pioneer work by Merigan in 1967 [1], many kinds of synthetic or natural polyanionic polymers have been examined for their biological activities [2-8], such as cytotoxicity, antiviral activity, antitumor activity, and immunomodulating activity. Although the biological results were interesting, the extent of activity for clinical application was still low. 

Finally, more and more experimental data must be collected in order to understand the biological (including antitumor) activity of organotin(IV) complexes... 

Polypropionate chains with alternating methyl and hydroxy substituents are structural elements of many natural products with a broad spectrum of biological activities (e.g. antibiotic, antitumor). The anti-anti stereotriad is symmetric but is the most elusive one. Harada and Oku described the synthesis and the chemical desymmetrization of meso-polypropionates [152]. More recently, the problem of enantiotopic group differentiation was solved by enzymatic transesterification. The synthesis of the acid moiety of the marine polypropionate dolabriferol (Figure 6.58a) and the elaboration of the C(19)-C(27) segment of the antibiotic rifamycin S (Figure 6.58b) involved desymmetrization of meso-polypropionates [153,154]. 

MORiNAGA T (1985) Studies on an antitumor polysaccharide RBS derived fi om rice bran. 1. Preparation, physico-chemical properties, and biological activities of RBS. Yakugaku Zasshi, 105(2) 188-93. 

There are numerous examples of intramolecular Heck reactions,151 such as in Entries 10 to 14. Entry 11 is part of a synthesis of the antitumor agent camptothecin. The Heck reaction gives an 11 1 endocyclic-exocyclic mixture. Entries 12-14 are also steps in syntheses of biologically active substances. Entry 12 is part of a synthesis of maritidine, an alkaloid with cytotoxic properties the reaction in Entry 13 is on a route to galanthamine, a potential candidate for treatment of Alzheimer s disease and Entry 14 is a key step in the synthesis of a potent antitumor agent isolated from a marine organism. 

The pyrrolizidines and indolizidines are a group of alkaloids that are characterized by the presence of the basic azabicyclo[3.3.0]octane and azabicyclo[4.3.0]nonane frameworks, respectively. These alkaloids exhibit remarkably diverse types of biological activity and have been reported to act as antitumor, hypotensive, anti-inflammatory, carcinogenic, or hepatoxic agents. Various pyrrolizidines and indolizidines have been prepared by 1,3-dipolar cycloaddition.115 Synthesis of these is described in the section 8.2 discussing cycloaddition. 

Most of the l,2,4-triazino-l,2,4,5-tetrazine derivatives 4 have been evaluated in vitro for antitumor activity. Results showed that these compounds exhibited a moderate anticancer activity toward leukemia <2003PS2055>. For biological activities of the previous compounds discussed in CHEC-II(1996), please refer to the same <1996CHEC-II(8)743>. 

Several reports are available on the biological activities of thioamide derivatives. The thioamide derivatives have shown significant activities, such as antituberculosis drug, anti-influenza virus activity, antitumor activity, anthelmintic activity, opioid receptor binding property, etc.94 101... 

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