Synthesis, physicochemical and pharmacological properties of pentacyclic alkaloid-analogues]

Quinazolinocarboline rutaecarpine and evodiamine (Evodia rutaecarpa) are main alkaloid components of traditional Chinese folk-remedies. Evodiamine exhibited selective antitumor and antimetastatic effects on several cancer cell lines and became lead structure of anticancer agents. During our synthetic research we achieved to gain alkaloid hybrid derivatives by combining the structural elements of quinazolinocarbolines with analogous alkaloids or drug molecules having similar effects by bioisosteric replacements. 8-norrutaecarpine, a hybrid molecule of rutaecarpine and luotonin A containing the indolo-pyrroloquinazolinone ring system has been synthesized. The hybrids of rutaecarpine and piroxicam bearing the indolo-pyridobenzothiazine and the 12-azaindolo-pyridobenzothiazine structures were prepared on two alternative routes. Two new heterocondensed pentacyclic compounds, 5-sulfarutaecarpine and 5-sulfa-8-norrutaecarpine were reached via bioisosteric replacement on the structure of rutaecarpine and 8-norrutaecarpine. Two new tricyclic ring systems, pyrido-benzothiadiazine and pyrrolo-benzothiadiazine were produced as intermediaries of these pentacyclic molecules. Series of substituted derivatives were prepared for pharmacological studies by modification of the structures with various substituents and solubilizing groups. During our work alternative way for synthesis of nauclefine (Nauclea latifolia) was laboured, and we published the synthesis of indolylquinazolinone derivative bouchardatine (Bouchardata neurococca) for the first time. Some of the physicochemical attributes of the synthesized intermediaries were defined, such as the pKa constants of 2,3-poly-methylene-benzothiadiazines. Proton/deuteron exchange kinetic constants of active methylene-groups of five tricyclic compounds were measured by 1H NMR technique. Solvent-dependent ratio of the Z/E isomers of phenyhydrazone-derivatives in polar and apolar solvents were determined. In the case of 18 produced compounds our work was completed by in vitro pharmacological studies performed within co-operation with the Institute of Pharmacology. The viability of HeLa cells was inhibited by five of our compounds to similar extent as the effect of evodiamine. Eight of our compounds induced apoptosis on HeLa cells to similar extent as evodiamine.