Sintesis N-benzil-4-metoksisinamamida dan Uji Aktivitasnya Sebagai Kandidat Senyawa Tabir Surya

SULFAH, Sugeng Triono, S.Si., M.Si.; Prof. Dr. Harno Dwi Pranowo, M.Si

2019 | Skripsi | S1 KIMIA

Telah dilakukan sintesis senyawa turunan amida sinamat (sinamamida) berbahan dasar 4-metoksisinamat dengan benzilamina. Tujuan penelitian ini adalah untuk mendapatkan metode alternatif sintesis 4-metoksisinamat, sintesis N-benzil-4-metoksisinamamida dan mempelajari potensi turunan sinamamida sebagai kandidat senyawa tabir surya. Sintesis turunan sinamat dilakukan dengan mereaksikan asam malonat dan 4-metoksibenzaldehida melalui reaksi kondensasi Knoevenagel dalam pelarut basa dimetilformamida dan katalis trietilamina menggunakan metode refluks selama 5 jam. Sintesis senyawa turunan sinamamida dilakukan melalui reaksi amidasi senyawa 4-metoksisinamat dengan benzilamina dalam pelarut toluena dan penambahan katalis asam borat (B(OH)3) 5% mol menggunakan metode refluks dan apparatus Dean-Stark Trap selama 10 jam. Struktur senyawa hasil sintesis dielusidasi dengan spektrometer FT-IR, GC-MS, DI-MS, dan 1H-NMR. Senyawa turunan sinamamida hasil sintesis diuji aktivitasnya sebagai tabir surya menggunakan spektrofotometer UV-Vis dan ditentukan nilai SPFnya. Hasil penelitian menunjukkan senyawa 4-metoksisinamat berupa padatan berbentuk jarum berwarna putih dengan rendemen 92% dengan titik leleh 172-173 oC. Pada senyawa N-benzil-4-metoksisinamamida diperoleh padatan berbentuk serbuk berwarna putih dengan rendemen 78% dengan titik leleh 123-125 oC. Hasil uji aktivitas tabir surya senyawa N-benzil-4-metoksisinamamida memiliki λmaks pada kisaran serapan sinar UV-B, yaitu 293 dan 308 nm dan memiliki nilai SPF sebesar 34,28 pada konsentrasi 25 µg/mL yang dapat dikategorikan sebagai kandidat tabir surya proteksi tinggi (high protection).

Synthesis of cinnamic amide (cinnamamide) derivative based on 4-methoxycinnamic with malonic acid have been conducted. The objectives of this research were to obtain an alternative methode to synthesis of 4-methoxy cinnamic, synthesis N-benzyl-4-methoxycinnamamide, and to study the potential of cinnamamide derivatives as candidate of sunscreen compound. Synthesis of cinnamic derivative was conducted using 4-methoxy benzaldehyde with malonic acid through Knoevenagel condensation reaction in dimethylformamide base solvent and triethylamine catalyst under reflux condition for 5 hours. Synthesis of the cinnamamide derivative compound was performed through amidation by refluxing with Dean-Stark Trap of 4-methoxycinnamic compound with benzylamine in toluene solvent and using boric acid (B(OH)3) 5% mol catalyst for 10 hours. The structures of the products were elucidated by FT-IR spectrometer, GC-MS spectrometer, DI-MS spectrometer, and 1H-NMR. The cinnamamide derivative product was tested for its activity as a sunscreen by UV-Vis spectrophotometer and its SPF value was determined. The results showed that 4-methoxycinamic was obtained as white needle solid with a yield of 92% and melting point 172-173 oC. Meanwhile, N-benzyl-4-methoxycinnamamide was obtained as white powder solids with a yield of 78% and melting point of 123-125 oC. The results of sunscreen activity test of the N-benzyl-4-methoxycinnamamide have λmax in the range of UV-B rays, 293 and 308 nm and have SPF values of 34.28 at a concentration of 25 µg / mL which can be categorized as a high protection sunscreen compound.

Kata Kunci : Sinamamida, tabir surya, kondensasi Knoevenagel, amidasi.