SINTESIS TURUNAN KHALKON DARI 2,4-DIHIDROKSIASETOFENON DENGAN VANILIN TERHALOGENASI DAN UJI AKTIVITASNYA SEBAGAI ANTIOKSIDAN

CHAIRUL RIJAL, Dr. Winarto Haryadi, M.Si.; Prof. Dr. Chairil Anwar

2022 | Tesis | MAGISTER KIMIA

Sintesis dan uji aktivitas antioksidan telah dilakukan untuk 3-kloro-4-hidroksi-5-metoksibenzaldehida (senyawa 1), 3-bromo-4-hidroksi-5-metoksibenzaldehida (senyawa 2), 2',4'-dihidroksi- 3-kloro-4-hidroksi -5-metoksihalkon (senyawa 3) dan 2',4'-dihidroksi-3-bromo-4-hidroksi-5-metoksihalkon (senyawa 4). Senyawa 1 diperoleh melalui reaksi klorinasi antara vanilin dengan Ca(ClO)2. Senyawa 2 diperoleh melalui reaksi brominasi antara vanilin dengan KBrO3 dalam pelarut asam asetat glasial dan katalis HBr. Senyawa 3 dan 4 diperoleh dari senyawa 1 dan 2 yang direaksikan dengan 2-4-dihidroksiasetofenon melalui kondensasi Claisen-Schmidt dengan menggunakan katalis basa KOH 40% dan KSF montmorillonit dalam pelarut metanol. Semua produk dilakukan karakterisasi menggunakan FTIR, GC-MS, TLC-Scanner, MS-Direct, 1H-NMR and 13C-NMR. Senyawa 1, 2, 3 dan 4 diuji aktivitas antioksidannya menggunakan DPPH. Hasil penelitian menunjukkan bahwa senyawa 1, 2, 3 dan 4 berhasil disintesis dengan rendemen masing-masing sebesar 52,77, 97,00, 1,86, dan 1,00 %. Hasil uji aktivitas antioksidan senyawa 1, 2, 3 dan 4 memiliki nilai IC50 sebesar 244,11, 269,44, 60,00 dan 162,10 ���¼g/mL. Berdasarkan nilai IC50 senyawa 1 dan 2 tidak memiliki aktivitas antioksidan terhadap DPPH. Senyawa 3 memiliki aktivitas dengan kategori kuat dan senyawa 4 memiliki aktivitas dengan kategori lemah terhadap DPPH

The syntheses and antioxidant activity test have been conducted for 3-chloro-4-hydroxy-5-methoxybenzaldehyde (compound 1), 3-bromo-4-hydroxy-5-methoxybenzaldehyde (compound 2), 2',4'-dihydroxy-3-chloro-4-hydroxy -5-methoxyhalcone (compound 3) and 2',4'-dihydroxy-3-bromo-4-hydroxy-5-methoxyhalcone (compound 4). Compound 1 was synthesized through a chlorination reaction between vanillin and Ca(ClO)2, Compound 2 was obtained by a bromination reaction between vanillin and KBrO3 in glacial acetic acid solvent with HBr catalyst. Compounds 3 and 4 were synthesized from compounds 1 and 2 which were reacted with 2-4-dihydroxyacetophenone by Claisen-Schmidt condensation using 40% KOH as a base catalyst and KSF montmorillonite in methanol. All synthesized compounds were characterized using FTIR, GC-MS, TLC-Scanner, MS-Direct, 1H-NMR and 13C-NMR. These compounds were also assessed for their antioxidant properties using DPPH. The results showed that compound 1, 2, 3 and 4 were succesfully synthesized with 52.77%, 97.00%, 1.86%, and 1.00% of yield, respectively. Based on the results of the antioxidant activity test, compounds 1, 2, 3 and 4 showed IC50 values of 244.11, 269.44, 60.00 and 162.10 ���¼g/mL, respectively. The IC50 values of compounds 1 and 2 suggested that these compounds did not have antioxidant activities against DPPH. Meanwhile, compound 3 has a strong category of activity and compound 4 has a weak category of activity against DPPH

Kata Kunci : klorinasi, brominasi, khalkon, antioksidan, DPPH