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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Design, synthesis and photobiological properties of 3,4-cyclopentenepsoralens
Ornella Gia1, Sebastiano Marciani Magno, Humberto Gonzalez-Diaz
1Department of Pharmaceutical Sciences, University of Padova, via Marzolo, 5, 35131 Padova, Italy.
Abstract:
The QSAR directed synthesis of tetracyclic psoralen derivatives (3-5) characterised by the condensation of a cyclopentane ring at the level of the 3,4 double bond of the tricyclic psoralen moiety is reported. The new compounds present a methoxy (3), a hydroxy (4) or a dimethylaminopropoxy (5) side chain inserted in position 8 of the lead chromophore. The evaluation of photoantiproliferative activity on human tumour cell lines reveals for 5 an ability to inhibit cell growth significantly higher with respect to that of the reference drug, 8-MOP. Interestingly, the enhancement in antiproliferative activity is accompanied by the disappearance of skin phototoxicity. On the other hand, no significant photobiological activity was scored for 3 and 4. The ability to photoreact with DNA, evaluated by isolating the 4',5' monoadduct and by estimating the ability to form interstrand cross-links, appeared to be significant for 5, practically negligible for 3 and 4. Furthermore, a back-projection of the more active compound identifies structural features suitable for further synthetic modifications.
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