Computational study of the interaction of santhemoidin C and 2-oxo-8-deoxyligustrin on TcTS

Chagas disease, caused by the parasite Trypanosoma cruzi, represents a worldwide epidemiological, economic, and social problem. In the last decades, the trans-sialidase enzyme of Trypanosoma cruzi has been considered an attractive target for the development of new agents with potential trypanocidal activity. TcTS from Trypanosoma cruzi has received particular interest as a highly stereospecific trans-sialidase. Trypanosoma cruzi is incapable of synthesizing sialic acid (SA) de novo. Consequently, the expression of the trans-sialidase (TcTS) enzyme allows the cleavage of terminal SA residues present in glycoconjugates of host tissues. Sialidases catalyze trans-sialylation reactions via a classical ping-pong mechanism . The SA obtained from this process is afterwards transferred onto mucins on the parasite surface, creating a protective and adhesive coat against the immune system. Additionally, TcTS shedding into the bloodstream induces alterations in the sialylation pattern of host cells, generating immune dysfunction and hematological alterations. TcTS represents a potentially attractive drug target against T. cruzi since it is absent in mammalian hosts and because of its role in parasite survival. Molecular docking computationally predicts the conformation of a small molecule when binding to a receptor. Scoring functions are a vital piece of any molecular docking pipeline as they determine the fitness of sampled poses. Molecular docking results revealed that the new cleft may serve to accommodate the glycosyl acceptor. In this paper, we aim to study the anti-T. cruzi properties of two STLs isolated from Stevia species. In this sense, in vitro activities against different parasite forms and possible molecular mechanisms of parasite
inhibition are explored.