(1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) is a β-carboline indole alkaloid naturally occurring in plants, foods, insects, and endogenously in mammals and humans. It exerts antioxidant and antithrombotic properties. MTCA is thought to be a possible causative substance of eosinophilia-myalgia syndrome associated with ingestion of L-tryptophan.

Elaiophylin (also known as Azalomycin-B) is a natural compound, a macrolide antibiotic that was first isolated from a culture of Streptomyces melanosporus. Elaiophylin is a novel and potent inhibitor of late-stage autophagy with outstanding antitumor activity in human ovarian cancer cells. In addition was shown, that elaiophylin could be a promising therapeutic strategy for overcoming incurable multiple myeloma (MM), even when TP53 mutations are present. It is known, that autophagy inhibition is a promising approach and is being investigated as a new target strategy for ovarian cancer treatment. Autophagy, a lysosome-dependent pathway, is a complex catabolic process that involves the degradation of dysfunctional or useless cytoplasmic constituents. Thus, elaiophylin, a novel autophagy inhibitor with unique chemical structure, provides the potential for structure-based development of autophagy inhibitors for new cancer therapies. Also, elaiophylin is an inhibitor of a testosterone 5 alpha-reductase.