A vast array of small, non-peptide, organic compounds that are biologically active. Products include receptor antagonists, molecular probes, metabolites, GPCR ligands, neurotransmitters, ion channel modulators, and signaling activators and inhibitors.
The fungal metabolite brefeldin A (BFA) has multiple targets in cells and has proven valuable for dissecting the cellular processes, including vesicle formation and kinesin distribution, involved in exporting newly synthesized proteins.