Tay Zugman

Scopus Publications

Efficacy of selenium- and tellurium-based organocompounds against ruminant gastrointestinal nematodes in vitro
Taynara Gabriele Ribeiro Piano, Irineu Romero Neto, Leandro Piovan, Leandro Bittencourt de Oliveira, Alda Lúcia Gomes Monteiro, et al.
Revista Brasileira De Parasitologia Veterinaria, 2026
Abstract Gastrointestinal nematode (GIN) infections significantly impact the health of ruminants. The indiscriminate use of anthelmintics contributes to the selection of drug-resistant parasites. Compounds containing selenium (Se) and tellurium (Te) have emerged as promising alternatives. This study aimed to evaluate the anthelmintic activity of diphenyl diselenide (PhSe)2, phenylselenenyl chloride (4-Cl-PhSe)2, and ammonium trichloro (dioxoethylene-O,O’) tellurate (AS-101) on eggs and larvae (L3) of GIN. The compounds were tested using egg-hatch and larval-migration inhibition tests. Additionally, the possible in vitro cytotoxic effects were evaluated using the AlamarBlue assay. (PhSe)2 exhibited the highest ovicidal effect, with a 50% inhibitory concentration (IC50) of 1.801 mmol L−1 for GIN isolated from sheep and 1.845 mmol L−1 for GIN from cattle. AS-101 showed the highest larvicidal activity, with IC50 values of 0.976 mmol L−1 for GIN of sheep and 1.035 mmol L−1 for GIN of cattle. Combinations of (PhSe)2 with ivermectin (IVM) showed a mild synergistic effect, with an additive interaction of 13.33%. Among the tested compounds, (PhSe)2 showed the lowest cytotoxicity in LLC-MK2 cells. Taken together, these data highlight the therapeutic potential of the novel molecules.
A blending-based therapeutic strategy using diaryl dichalcogenides and ivermectin against gastrointestinal nematodes of small ruminants
Irineu Romero-Neto, Júlia Dall’Anese, Tay Zugman, Eduarda Proença, Alda Lúcia Gomes Monteiro, Leandro Piovan, Marcelo Beltrão Molento
Veterinary Parasitology, 2025
New Dichalcogenides Induce Oxidative Stress and Cell Death of Leishmania amazonensis
Andressa Dalólio Valente, Rian Richard Santos de Farias, Tay Takeshita Botogoske Zugman, Leandro Piovan, Celso Vataru Nakamura, Francielle Pelegrin Garcia
Drug Development Research, 2024
Leishmaniasis are caused by protozoa of the genus Leishmania and affect millions of people worldwide. They are considered neglected diseases that primarily impact individuals in tropical and subtropical regions. The drugs currently available for treating this infection have limitations, such as high toxicity, adverse reactions, and a long therapeutic intervention period. Numerous studies, using various experimental models, have sought to develop more effective and less toxic chemotherapeutic agents against these protozoa. In this context, the present study aimed to evaluate the antileishmanial activity of two new dichalcogenides, LQ64 and LQ62, as well as their possible mechanism of action in promastigote forms of Leishmania amazonensis. Both substances, LQ64 and LQ62, exhibited activity against promastigote (IC50 = 2.35 and 12.59 µM, respectively), and amastigote forms (IC50 = 3.50 and 6.58 µM, respectively). Furthermore, the substances revealed selectivity for the parasite when analyzing their cytotoxicity in J774A‐1 macrophages. Moreover, electron microscopy analysis and mechanisms of action assays investigated in promastigote forms with both substances showed mitochondrial depolarization. This phenomenon possibly promoted changes in intracellular ATP levels, resulting in increased reactive species and lipid peroxidation, leading the parasites to oxidative stress. Additionally, the treatments induced changes in plasma membrane integrity, lipid body accumulation, alterations in the cell cycle, and phosphatidylserine externalization. Thus, the results indicate that LQ64 and LQ62 may induce characteristic changes in the protozoan suggestive of apoptosis cell death.
Ovicidal activity of diaryl dichalcogenides and ivermectin on Fasciola hepatica: A novel candidate for a blending-based therapeutic strategy
Irineu Romero-Neto, Thayany Magalhães de Almeida, Tay Zugman, Leandro Piovan, Marcelo Beltrão Molento
Acta Tropica, 2024
Exquisite use of Selenoesters as Recyclable Acyl Donors for Lipases-catalyzed Kinetic Resolution
Tay Zugman, Maria Clara da Silva Durigon, Suelem Kluconski Campos, Rodolfo Rodrigues da Silva, Thiago Sabino da Silva, Alfredo Ricardo Marques de Oliveira, Leandro Piovan
Chemistryselect, 2022
Abstract Lipase‐catalyzed enantioselective synthetic reactions employing enol esters, activated esters, anhydrides, and oximes as acyl donors is a well‐consolidated strategy towards enantiopure compounds. However, lipases can also cleave the C−S bond of thioesters, proving that other classes of substances can be used as acyl donors in lipase‐catalyzed transformations. Herein we describe the application of selenoesters as a new class of acyl donors in enzymatic kinetic resolution of chiral alcohols. A series of selenoesters was successfully employed in the resolution of chiral primary and secondary alcohols, demonstrating that lipases can also cleave the C−Se bond. Assays using selenoesters as acyl donors in lipase‐catalyzed reactions furnished enantiopure compounds (e.e.>99 %) and enantiomeric ratio (E>200). We also observed that the enzymatic reaction is accelerated in an oxygen atmosphere and performing a preparative scale reaction could demonstrate how simple and easy the purification process is to recover the diselenide formed during the resolution.
Complementary performance of organoselenides and organotellurides as antimicrobials agents
Felipe Borges, Tay Zugman, Pamela Bandeira, Mara Dalmolin, Débora Scariot, Francielle Garcia, Alfredo de Oliveira, Celso Nakamura, Leandro Piovan
Journal of the Brazilian Chemical Society, 2021
Fungi and bacteria are well-known pathogens for plants, fruits, and animals, including humans. In this context, the prospection of antimicrobial agents is crucial to provide new alternatives for the treatment of microbial diseases. Hence, seleniumand tellurium-containing compounds are underexploited and herein, antimicrobial activity of several organochalcogenated compounds was evaluated against Gram-negative and Gram-positive bacteria and fungi. A direct comparison between Seand Te-containing compounds was performed, as well as structure-activity relationship studies. Among assayed compounds, secondary Se-amines LQ16 and LQ20 and secondary Te-amine LQ28 showed excellent results against a variety of fungi, while primary Te-amine LQ10 demonstrated promising results against bacteria. These results suggest organoselenides and organotellurides may be used for the development of new antimicrobial agents.