Figure 6.

PCA based on molecular descriptors of compounds detected and identified in the EPfB library shows that the retrieved bacterial metabolites cover the chemical space of the approved drugs. (a) Chemical space coverage of identified compounds from consensus spectra exclusively detected in the following growth conditions: elicited (blue), controls (white) and both (yellow). Compounds found in the bioactive fractions are denoted by a red edge. For reference, compounds present in the UNPD-ISDB database (n = 208,009 natural products) and the DrugBank (subset of approved drugs, n = 2078 drugs) were also used in the PCA analysis and are shown in grey and salmon, respectively. A zoomed view at the central region of the PCA is shown in the inset for better visualization. (b) The PC1 and PC2 axes that separate the four quadrants (Q1 to Q4) are shown in black dotted lines. The main variables of contributing molecular descriptors are shown and labeled. (c) Relative frequency of compounds found in each quadrant by chemical collection/set.