Sazeli S, Nath AR, Ahmad MH, Zulkifli NWM, Johan MR, Yehye WA, Voon LH. Semicarbazide and thiosemicarbazide containing butylated hydroxytoluene moiety: new potential antioxidant additives for synthetic lubricating oil.
RSC Adv 2021;
11:7138-7145. [PMID:
35423237 PMCID:
PMC8691112 DOI:
10.1039/d0ra10626g]
[Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/01/2021] [Indexed: 01/20/2023] Open
Abstract
New multipotent antioxidants (MPAOs), namely semicarbazides and thiosemicarbazides bearing thiolated butylated hydroxytoluene (BHT), were synthesized. The antioxidant activity of the synthesized compounds was evaluated using in vitro DPPH assay. Compounds containing thiosemicarbazides (5a′–h′) were found more active in free radical scavenger than semicarbazides (5a–h). Among the other compounds, compound 5f′ (IC50 of 25.47 ± 0.42 μM) showed the best antioxidant activity against DPPH radicals compared to standard antioxidant butylated hydroxytoluene (BHT). Based on DPPH results, compound 5f′ and its corresponding semicarbazide 5f were blended into trimethylolpropane trioleate (TMPTO) and isothermal differential scanning calorimetry (DSC) was carried out for the investigation of oxidative stability. At 125 °C isothermal DSC, TMPTO with 0.25 wt% of 5f′ showed 1.5 times higher oxidation stability than its corresponding semicarbazide 5f and was 2 times better than BHT. It was anticipated that due to the strong auto-synergistic effect, compound 5f′ showed promising oxidative stability to TMPTO by protecting from pre-mature oxidative degradation.
New multipotent antioxidants (MPAOs), namely semicarbazides and thiosemicarbazides bearing thiolated butylated hydroxytoluene (BHT), were synthesized.![]()
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