84280-95-5Relevant articles and documents
Synthesis, Antioxidant Activity and Cytotoxicity of N-Functionalized Organotellurides
Bandeira, Pamela T.,Dalmolin, Mara C.,de Oliveira, Mariana M.,Nunes, Karine C.,Garcia, Francielle P.,Nakamura, Celso V.,de Oliveira, Alfredo R.M.,Piovan, Leandro
, p. 410 - 415 (2019)
The use of antioxidants is the most effective means to protect the organism against cellular damage caused by oxidative stress. In this context, organotellurides have been described as promising antioxidant agents for decades. Herein, a series of N-functionalized organotellurium compounds has been tested as antioxidant and presented remarkable activities by three different in vitro chemical assays. They were able to reduce DPPH[rad] radical with IC50 values ranging from 5.08 to 19.20 μg mL?1, and some of them also reduced ABTS[rad]+ radical and TPTZ-Fe3+ complex in ABTS[rad]+ and FRAP assays, respectively. Initial structure-activity relationship discloses that the nature of N-substituent strongly influenced both activity and cytotoxicity of the studied compounds. Furthermore, radical scavenging activities of N-functionalized organotellurides have been compared with those of their selenilated congeners, demonstrating that the presence of tellurium atom has an essential role in antioxidant activity.
Stereoselective Bioreduction of Telluro-Acetophenones to Optically Active Hydroxy Tellurides
Bandeira, Pamela Taisline,Gotor-Fernández, Vicente,Piovan, Leandro
, (2020/02/27)
Organotellurium compounds exhibit a broad range of useful applications in organic synthesis, materials science and medicinal chemistry fields. Despite their increasing applicability, the synthesis of enantiomerically pure organotellurium compounds remains nowadays scarcely reported in the literature. Herein, the chemical synthesis and biocatalyzed reductions of a set of telluro-acetophenones using both (R) and (S)-selective alcohol dehydrogenases (ADHs) is described for the first time, obtaining enantiomerically enriched hydroxy tellurides with excellent selectivities under very mild reaction conditions. On the one hand, enantiopure para-substituted (S)-hydroxy tellurides were obtained using the Ras-ADH (77–95 % conversion) and ADH-A (52–75 %), the ADH-A leading to the enantiopure (S)-hydroxy tellurides substituted at the meta-position (69–75 %). On the other hand, the evo-1.1.200 displayed high selectivity towards the preparation of optically alcohols with substitutions at the para-position of the aromatic ring (60–68 % conversion and 92–97 % ee), while the Lb-ADH led to the best results when reducing bulky ketones at the meta-position (79–82% conversion and 88–99 % ee).
Diacetal Ditellurides as Highly Active and Selective Antiparasitic Agents toward Leishmania amazonensis
Bandeira, Pamela T.,Souza, Jo?o Pedro A.,Scariot, Débora B.,Garcia, Francielle P.,Nakamura, Celso V.,De Oliveira, Alfredo R. M.,Piovan, Leandro
, p. 806 - 810 (2019/05/06)
Leishmaniasis is a neglected tropical disease and a public health concern in at least 98 countries, affecting mainly the poorest populations. Pharmaceuticals and chemotherapies available for leishmaniasis treatment have several limitations, which clearly justify the efforts to find new potential antileishmanial drugs. In this context, antiprotozoal activities toward different Leishmania species have been reported for hypervalent tellurium compounds, which motivated us to investigate, for the first time, the leishmanicidal properties of some nonhypervalent diaryl ditellurides. Thus, this work describes in vitro activity against Leishmania amazonensis and the cytotoxicities of diaryl ditellurides. Ditelluride LQ7 revealed a strong leishmanicidal activity on promastigotes and amastigotes at submicromolar levels (IC50 = 0.9 ± 0.1 and 0.5 ± 0.1 μmol L-1, respectively) and presented selectivity indexes greater than those of reference drug miltefosine. This preliminary study suggests that diaryl ditellurides may be promising scaffolds for the development of new agents for leishmaniasis treatment.
