a Chemometric (statistical) methods are employed to classify a set of neolignan compounds with activity against Paracoccidioides brasiliensis. The AM1 (Austin Model 1) method was used to calculate a set of molecular descriptors (properties) of the neolignan compounds under study. The descriptors were further analyzed using Principal Components Analysis (PCA), Hierarchical Cluster Analysis (HCA) and K-Nearest Neighbor (KNN) chemometric methods. The PCA and HCA methods were quite efficient to

more »

... sify the compounds into two groups (active and inactive) and three descriptors were found to be important in the classification: the highest occupied molecular orbital energy (E HOMO ), the bond order between C 1' -R 7 atoms (L 14 ) and the bond order between C 5' -R 6 atoms (L 22 ). The three variables responsible for the separation between active and inactive compounds are all electronic descriptors, therefore we can conclude that electronic effects should have an important role when one is trying to understand the activity of neolignan compounds against Paracoccidioides brasiliensis.