SINTESIS DAN UJI ANTIBAKTERI SENYAWA PIRAZOLINA N1-HIDROGEN DAN N1-BENZOIL DARI VANILIN DAN VERATRALDEHIDA; SYNTHESIS AND ANTIBACTERIAL TEST OF N1-HYDROGEN AND N1-BENZOYL PYRAZOLINES FROM VANILLIN AND VERATRALDEHYDE

PUTRA JIWAMURWA PAMA TJITDA, Tutik Dwi Wahyuningsih

2015 | Disertasi | FMIPA

Syntheses of N1-hydrogen and N1-benzoyl pyrazoline derivatives and antibacterial test in vitro have been carried out. The aims of this research is studying the synthesis of N1-hydrogen and N1-benzoyl pyrazoline derivatives within study the effect of N1-benzoyl against antibacterial activity. Reaction step was started from the synthesis of precursor compound which is chalcone. Chalcone A compound was obtained by reaction of vanillin and 2?- hydroxychalcone in the presence of NaOH 40% as catalyst for 4 h. While chalcone B compound was produced by condensation reaction between veratraldehyde and 2?-hydroxychalcone in similar condition to chalcone A compound. The second step is synthesis of N1-hydrogen pyrazoline. N1-hydrogen pyrazoline A was synthesized from cyclisation reaction both chalcone A compound and hydrazine monohydrate for 2 h. Whereas N1-hydrogen pyrazoline B was obtained by cyclisation reaction of chalcone B compound and hydrazine monohydrate for 4 h. The third is synthesis N1-benzoyl pyrazoline. Each N1- hydrogen A and B pyrazolines were reacted with benzoyl chloride and acetic acid glacial as catalyst for 2 h to produce N1-benzoyl A and B pyrazolines. The synthesis method for all compound is reflux. The elucidation of structure products obtained used FTIR, GC-MS, 1H- and 13C-NMR spectrometers. Antibacterial test conducted by disk diffusion method against Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus, Bacillus subtilis) and Gram-negative (Escherichia coli, Shigella flexneri). Claisen-Schmidt condensation reaction between vanillin and 2- hydroxychalcone produced chalcone A in 55.39% yield. While chalcone B was synthesized from veratraldehyde and 2-hydroxychalcone to yield 77.97%. N1- hydrogen A and B pyrazoline compounds have been successfully synthesized in 76.22 and 84.39% yield, respectively. Modification of N1-hydrogen pyrazoline into N1-benzoyl A and B pyrazolines have been also successfully performed 50.74 and 82.49% yield, respectively. Antibacterial test results indicate that the presence of N-benzoyl substituent decreases antibacterial activity and is only active on Gram-positive bacteria. While the N1-hydrogen pyrazoline compounds have a good antibacterial activity against Gram positive and Gram negative bacteria.

Kata Kunci : N1-hydrogen pyrazoline; N1-benzoyl pyrazoline; antibacterial.