SINTESIS 2apostrophe,6apostrophe-DIHIDROKSI-3,4-DIMETOKSIKHALKON DAN 5-HIDROKSI-3apostrophe,4apostrophe-DIMETOKSIFLAVON SERTA UJI AKTIVITASNYA SEBAGAI ANTIBAKTERI

STEVIN CAROLIUS, Prof. Drs. Sabirin Matsjeh, Ph.D. ; Dr. Winarto Haryadi, M.Si.

2016 | Skripsi | S1 KIMIA

Sintesis 2',6'-dihidroksi-3,4-dimetoksikhalkon dan 5-hidroksi-3',4'-dimetoksiflavon serta uji aktivitasnya sebagai antibakteri telah dilakukan.Penelitian ini diawali dengan sintesis khalkon melalui reaksi Claisen-Schmidtberbahan dasar veratraldehida, 2,6-dihidroksiasetofenon dan katalis basa NaOHmelalui metode penggerusan selama 30 menit pada temperatur kamar. Selanjutnyasintesis flavon dilakukan melalui siklisasi secara oksidatif dengan mereaksikankhalkon hasil sintesis dan I2 dalam pelarut dimetilsulfoksida menggunakanmetode refluks selama 45 menit. Elusidasi struktur senyawa khalkon dan flavonhasil sintesis dilakukan menggunakan spektrometer FT-IR, GC-MS dan 1H-NMR.Kedua senyawa hasil sintesis diuji aktivitas antibakterinya menggunakan metodedifusi sumur terhadap bakteri Gram positif (Staphyloccocus aureus, Bacilluscereus) dan Gram negatif (Salmonella typhimurium, Escherichia coli). Senyawa 2',6'-dihidroksi-3,4-dimetoksikhalkon berhasil disintesis dengan rendemen 20,08% berupa padatan berwarna kuning dan titik leleh 144-146 C. Senyawa 5-hidroksi-3',4'-dimetoksiflavon berhasil disintesis dengan dengan rendemen 68,90% berupa padatan berwarna coklat dan titik leleh 328-333 C.Hasil uji antibakteri menunjukkan bahwa senyawa hasil sintesis memiliki aktivitas antibakteri terhadap bakteri Gram positif dan Gram negatif. Aktivitas tertinggi terhadap bakteri Staphylococcus aureus, Bacillus cereus, Salmonella typhimurium dan Escherichia coli berturut-turut ditunjukkan dengan nilai diameter daya hambat (mm)/konsentrasi senyawa uji (ppm) untuk 2',6'-dihidroksi-3,4- dimetoksikhalkon sebesar 2,97/1000; 4,52/1000; 3,94/1000; dan 4,42/700 sedangkan untuk 5-hidroksi-3',4'-dimetoksiflavon sebesar 3,22/1000; 4,82/1000; 4,20/1000; dan 5,80/500.

Synthesis of 2',6'-dihydroxy-3,4-dimethoxychalcone and 5-hydroxy-3',4'-dimethoxyflavone with its activity test as antibacterial have been carried out. This research was began with synthesis of chalcone through Claisen-Schmidt reaction by reacting veratraldehyde and 2,6-dihydroxyacetophenone with NaOH as base catalyst via grinding methods for 30 minutes at room temperature. Furthermore, flavone was synthesized through oxidative cyclization by refluxing the synthesized chalcone and I2 in dimethylsulfoxide for 45 minutes. Structure elucidation of chalcone and flavone compounds were confirm by FT-IR, GC-MS and 1H-NMR spectrometers. The produced compounds were tested for its antibacterial activity by agar well diffusion method against Gram positive (Staphyloccocus aureus, Bacillus cereus) and Gram negative bacteria (Salmonella typhimurium, Escherichia coli). The 2',6'-dihydroxy-3,4-dimethoxychalcone was obtained as yellow solid in 20.08% yield and its melting point is 144-146 C. The 5-hydroxy-3',4'-dimethoxyflavone was obtained as brown solid in 68.90% yield and its melting point is 328-333 C. Antibacterial test showed that produced compounds were active against Gram positive and Gram negative bacteria. Highest activity against Staphylococcus aureus, Bacillus cereus, Salmonella typhimurium, and Escherichia coli showed by its inhibition zone (mm)/tested compound concentration (ppm) for 2',6'-dihydroxy-3,4-dimethoxychalcone were 2.97/1000; 4.52/1000; 3.94/1000; and 4.42/700 meanwhile for 5-hydroxy-3',4'- dimethoxyflavone were 3.22/1000; 4.82/1000; 4.20/1000; and 5.80/500 respectively.

Kata Kunci : Khalkon, flavon, antibakteri