RESUMO
Lignans are a large class of natural products that have been isolated from many plants. They reveal diverse biological activities, especially antiviral and antitumor properties. From Piper cubeba, lignans of several classes can be isolated from the roots, rhizomes, stems, leaves, seeds, and fruits. Among its various chemical constituents, (-)-cubebin and (-)-hinokinin are found in significant quantities. Although they have been known for some time, during the last few decades their biological properties have been studied by several research groups. The cubebins have been identified as a lactol monomer and dimers as a mixture of diastereoisomers. Recently, their structural characterization and the synthesis of the possible structures have led to the correction of some earlier structural proposals. This review describes the more recent developments in the study of the medicinal attributes of cubebin and hinokinin extracted from Piper cubeba and the synthesis and biological testing of some analogues.
RESUMO
(-)-Cubebin (CUB), isolated from seeds of Piper cubeba, was used as starting material to obtain the derivatives (-)-hinokinin (HK) and (-)-O-benzyl cubebin (OBZ). Using paw edema as the experimental model and different chemical mediators (prostaglandin and dextran), it was observed that both derivatives were active in comparison with both negative (5% Tween® 80 in saline) and positive (indomethacin) controls. The highest reduction in the prostaglandin-induced edema was achieved by OBZ (66.0%), while HK caused a 59.2% reduction. Nonetheless, the dextran-induced paw edema was not significantly reduced by either of the derivatives (HK or OBZ), which inhibited edema formation by 18.3% and 3.5%, respectively, in contrast with the positive control, cyproheptadine, which reduced the edema by 56.0%. The docking analysis showed that OBZ presented the most stable ligand-receptor (COX-2 - cyclooxygenase-2) interaction in comparison with CUB and HK.