Electro-oxidation of hispanolone and anti-inflammatory properties of the obtained derivatives.
The electrochemical oxidation ((+)Pt-Ni(-)/NH(4)Br/MeOH) of the natural product hispanolone (1a) produced, in high yield (>95%), spiro-tetracyclic compounds 7a-7d as a result of the intramolecular addition of the C-9 hydroxyl group into the C-16 position with the simultaneous addition of a CH(3)O group at the C-15 position of the hispanolone furan moiety. After the electrochemical oxidation, an acid-catalyzed slow secondary reaction occurred producing the previously undescribed alpha-butenolide derivative, iso-Leopersin G (9). An anti-inflammatory study with the electro-synthesized compounds showed that 1a has higher anti-inflammatory properties with very low cytotoxicity (e.g., the inhibition of TPA-induced ear edema assay IC(50) = 1.05 microM/ear, positive control indomethacin IC(50) = 0.27 microM/ear).
Nieto-Mendoza
Elizabeth
E
Instituto de Química de la Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Coyoacán C.P. 04510, Mexico.
Guevara-Salazar
Juan A
JA
Ramírez-Apan
María Teresa
MT
Frontana-Uribe
Bernardo A
BA
Cogordan
Juan A
JA
Cárdenas
Jorge
J
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D010084:Oxidation-Reduction
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000970:Antineoplastic Agents; D004224:Diterpenes; C501367:hispanolone; C501368:iso-leopersin G