Senyawa turunan tiosemikarbazon adalah senyawa kimia yang memiliki sifat aktivitas biologis yang cukup baik. Pada penelitian kali ini, telah dilakukan sintesis senyawa turunan tiosemikarbazon dengan menggunakan limonen dan kamfen dengan empat senyawa aldehida aromatik yang berbeda yaitu benzaldehida, 2-hidroksibenzaldeh ida, 4-metoksibenzaldehida, dan sinamaldehida. Produk akhir senyawa turunan tiosemikarbazon yang terbentuk diidentifikasi menggunakan KLT serta dikarakterisasi menggunakan Fourier Transform Infra-red spectroscopy (FTIR), dan Liquid Chromatography Mass Spectrometry (LC-MS/MS). Produk hasil akhir senyawa turunan tiosemikarbazon diuji aktivitas antioksidannya dengan menggunakan metode 1,1-Difenil-2-pikril-hidrazil (DPPH). Kedelapan produk akhir, yaitu benzaldehida limonen tiosemikarbazon (1), 2-hidroksibenzaldehida limonen tiosemikarbazon (2), 4-metoksibenzaldehida limonen tiosemikarbazon (3), sinamaldehida limonen tiosemikarbazon (4), benzaldehida kamfen tiosemikarbazon (5), 2-hidroksibenzaldehida kamfen tiosemikarbazon (6), 4-metoksibenzaldehida kamfen tiosemikarbazon (7), dan sinamaldehida kamfen tiosemikarbazon (8) memiliki hasil masing-masing sebesar 76,32%; 80,75%; 91,79%; 71,61%; 96,82%; 89,94%; 87,98%; dan 97,65%. Berdasarkan uji aktivitas antioksidan menggunakan metode DPPH, diperoleh IC50 senyawa (1), (2), (3), (4), (5), (6), (7), dan (8) sebesar 158,64 ppm; 76,35 ppm; 107,38 ppm; 170,82 ppm; 152,92 ppm; 84,56 ppm; 118,34 ppm; dan 175,69 ppm.

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Thiosemicarbazone derivatives are chemical compounds known for their significant biological activity. In this study, thiosemicarbazone derivatives were synthesized using limonene and camphene with four different aromatic aldehydes: benzaldehyde, 2-hydroxybenzaldehyde, 4-methoxybenzaldehyde, and cinnamaldehyde. The final thiosemicarbazone derivative products were identified using Thin Layer Chromatography (TLC) and characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Liquid Chromatography-Mass Spectrometry (LC-MS/MS). The antioxidant activity of the final thiosemicarbazone derivative products was tested using the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) method. The yields of the eight final products, benzaldehyde limonene thiosemicarbazone (1), 2-hydroxybenzaldehyde limonene thiosemicarbazone (2), 4-methoxybenzaldehyde limonene thiosemicarbazone (3), cinnamaldehyde limonene thiosemicarbazone (4), benzaldehyde camphene thiosemicarbazone (5), 2-hydroxybenzaldehyde camphene thiosemicarbazone (6), 4-methoxybenzaldehyde camphene thiosemicarbazone (7), and cinnamaldehyde camphene thiosemicarbazone (8), were 76.32%, 80.75%, 91.79%, 71.61%, 96.82%, 89.94%, 87.98%, and 97.65%, respectively. Based on the antioxidant activity test using the DPPH method, the IC50 values of compounds (1), (2), (3), (4), (5), (6), (7), and (8) were found to be 158.64 ppm; 76.35 ppm; 107.38 ppm; 170.82 ppm; 152.92 ppm; 84.56 ppm; 118.34 ppm; and 175.69 ppm, respectively.