CHEMOTYPE VERBOCCIDENTAFURAN IN Baccharis punctulata (Asteraceae): FURANIC SESQUITERPENES CORRELATION AND MOLECULAR DOCKING INTO THE BENZODIAZEPINE RECEPTOR

The compound verboccidentafuran (1) was identified from the essential oil of the leaves of Baccharis punctulata DC. (Asteraceae) specimens for the first time in Brazil. The variation of this compound found in male and female specimens may be associated to the existence of more than one type of chemotype, influenced by geographic variation, climatic conditions, stage of the vegetative cycle, genetic and ecological factors. The furanocadinan-type sesquiterpenes verboccidentafuran (1) and curzerene (2) have molecular descriptors with high similarities. Compound 2, found in Eugenia uniflora L. (Myrtaceae) and species of the genus Smyrnium L. (Apiaceae), is active to control seizures induced by pentylenetetrazole, what suggests a possible binding to the benzodiazepine-site of the GABAA (gamma-aminobutyric acid type A) receptor. Considering the occurrence and availability of 1 in the species B. punctulata and its structural similarity to compound 2, docking calculations were performed for the interaction of both compounds with the human α1-β2-γ2 GABAA receptor. The results suggest that both compounds 1 and 2 must have affinity for the cavity at α1-γ2 interface and support the development of pharmacological research on the compound verboccidentafuran 1 as a drug candidate for modulating the GABA/benzodiazepine complex in the central nervous system.