SINTESIS DAN UJI AKTIVITAS ANTIBAKTERI SECARA IN VITRO TURUNAN KLOROPIRAZOLINA BERBAHAN DASAR VANILIN

ESTIN NOFIYANTI, Dr. Tutik Dwi Wahyuningsih, M.Si

2014 | Tesis | S2 Ilmu Kimia

Sintesis dan uji antibakteri secara in-vitro senyawa kloropirazolina dari vanilin atau veratraldehida dengan p-kloroasetofenon telah dilakukan. Penelitian dilakukan melalui tahap sintesis senyawa kalkon 1a dan 1b dari veratraldehida atau vanilin dengan p-kloroasetofenon dan sintesis pirazolina 2a dan 2b dari kalkon 1a atau 1b dengan fenilhidrazin. Kemudian dilakukan uji aktivitas antibakteri senyawa pirazolina 2a dan 2b. Sintesis kalkon 1a dilakukan menggunakan metode pengadukan pada temperatur ruang terhadap veratraldehida, p-kloroasetofenon dan NaOH 30% (b/v) selama 4 jam, sedangkan kalkon 1b disintesis dari vanilin, p-kloroasetofenon dan NaOH 60% (b/v) selama 24 jam. Sintesis pirazolina 2a dan 2b dilakukan dengan mereaksikan kalkon 1a atau kalkon 1b dengan fenilhidrazin dalam suasana asam menggunakan metode refluks selama 4 jam. Semua produk kalkon dan pirazolina dilakukan analisis struktur menggunakan FTIR, GC-MS dan spektrometer 1H dan 13C-NMR. Senyawa pirazolina yang terbentuk diuji aktivitas antibakteri secara in-vitro terhadap Staphylococcus aureus, Bacillus cereus, Bacillus subtillis, Escherichia coli dan Shigella flexnerri menggunakan metode difusi sumuran. Hasil penelitian menunjukkan senyawa kalkon 1a dan 1b telah berhasil disintesis dari veratraldehida atau vanilin dengan p-kloroasetofenon dengan rendemen berturut-turut sebesar 79,07 dan 59,22%. Sintesis Senyawa pirazolina 2a dan 2b telah berhasil disintesis dari kalkon 1a atau kalkon 1b dengan fenilhidrazin dalam suasana asam menghasilkan rendemen berturut-turut sebesar 52,90 dan 93,10%. Uji antibakteri menunjukkan bahwa senyawa pirazolina 2a dan 2b memiliki aktivitas antibakteri terhadap bakteri gram positif dan gram negatif. Pirazolina 2a memiliki aktivitas antibakteri dengan nilai zona penghambatan/konsentrasi pada Staphylococcus aureus (8,75/300), Bacillus cereus (7,75/1000), Bacillus subtillis (6,50/1000), dan Escherichia coli (3,50/300). Pirazolina 2b memiliki aktivitas antibakteri terhadap semua bakteri dengan nilai zona penghambatan/konsentrasi pada Staphylococcus aureus (4,75/100), Bacillus cereus (2,50/500), Bacillus subtillis (4,50/300), Escherichia coli (4,75/500) dan Shigella flexnerri (3,75/300). Hasil tersebut menunjukkan bahwa adanya subtituen kloro, hidroksi dan metoksi pada senyawa turunan pirazolina mampu menghambat pertumbuhan bakteri patogen yang diujikan.

Synthesis and in-vitro test of antibacterial activity of some chloropyrazoline derivatives from vanillin or veratraldehyde with pchloroacetophenone was performed. The research was carried out through three steps. The first step was synthesis of chalcone from veratraldehyde or vanillin with p-chloroacetophenone to give chalcone 1a and 1b. The second step was synthesis of pyrazoline from chalcone 1a and 1b with phenylhydrazine to give pyrazoline 2a and 2b. The final step was in-vitro test of antibacterial activity of pyrazolines 2a and 2b. Synthesis of chalcone 1a was performed by stirring veratraldehyde, p-chloroacetophenone and NaOH 30% (b/v) at room temperature for 4 h, while chalcone 1b was performed by stirring vanillin, p-chloroacetophenone and NaOH 60% (b/v) at room temperature for 24 h. Synthesis of pyrazoline 2a and 2b were performed by refluxing the chalcone 1a and 1b with phenylhydrazine in acidic condition for 4 h. The structure of the synthesized compounds was confirmed by FTIR, GC-MS and 1H and 13C-NMR spectrometers. The pyrazolines (2a and 2b) were screened for antibacterial activity by agar well-diffusion against Staphylococcus aureus, Bacillus cereus, Bacillus subtillis, Escherichia coli and Shigella flexnerri The result showed that chalcone 1a and 1b had been successfully synthesized by the reaction of veratraldehyde or vanillin with pchloroacetophenone. The yields were 79.07 and 59.22% respectively. Pyrazoline 2a and 2b had been synthesized from chalcone 1a or 1b with phenylhydrazine to give 52.90 and 93.10% yield, respectively. Antibacterial screening showed that both pyrazoline 2a and 2b were active against selected gram positive and negative bacterial. Pyrazoline 2a was found to exhibits an antibacterial activity and its zone of inhibition/concentration against Staphylococcus aureus (8.75/300), Bacillus cereus (7.75/1000), Bacillus subtillis (6.50/1000), and Escherichia coli (3.50/300). Pyrazoline 2b was found to exhibits an antibacterial activity and its zone of inhibition/concentration against Staphylococcus aureus (4.75/100), Bacillus cereus (2.50/500), Bacillus subtillis (4.50/300), Escherichia coli (4.75/500) and Shigella flexnerri (3.75/300). The result showed that pyrazoline derivatives which were subtituted with chloro, hydroxyl and methoxy, were able to inhibit the growth of the tested pathogenic bacteria

Kata Kunci : kalkon, pirazolina, antibakteri, vanilin, veratraldehida