SINTESIS TURUNAN PIRAZOLINA SEBAGAI AGEN ANTIBAKTERI DARI VANILIN DAN MINYAK GANDAPURA; SYNTHESES OF PYRAZOLINE DERIVATIVES AS ANTIBACTERIAL AGENTS FROM VANILLIN AND WINTERGREEN OIL

Setyawati, Amri, Tutik Dwi Wahyuningsih

2015 | Disertasi | FMIPA

The pyrazoline derivatives (3a-3b) and benzohydrazide (3c) have been synthesized from 5-bromovanillin (1) through chalcone intermediate (2). They have been tested as antibacterial agents by diffusion method. Pyrazolines were produced from vanillin while benzohydrazide was produced from wintergreen oil. Pyrazoline 3a was synthesized by refluxing chalcone with hydrazine monohydrate in methanol, while N-acetyl pyrazoline 3b was refluxed in glacial acetic acid. Benzohydrazide was formed by stirring chalcone and salicyl hydrazine at room temperature. The structure of all products was elucidated by spectrometers FTIR, GCMS, 1H- and 13C-NMR. Pyrazolines and benzohydrazide products were tested as antibacterial agents to against growth of Staphylococcus aureus, Bacillus subtilis, Bacillus cereus (Gram positive) and Escherichia coli, Shigella flexnerri (Gram negative) with tetracycline as positive control and DMSO 99.99% as negative control. The result showed that 5-bromovanillin (1), chalcone (2), pyrazoline (3a), pyrazoline (3b) and benzohydrazide (3c) were produced in 98, 78, 87, 88, and 33% yield, respectively. All of the tested compounds showed antibacterial activity in broad spectrum and pyrazoline (3b) showed increasing antibacterial activity for Gram positive. The highest antibacterial activity of pyrazoline was obtained by pyrazoline (3b) to against Staphylococcus aureus (1000 ppm: 7.25 mm) while benzohydrazide at (3c) for Bacillus subtilis (1000 ppm: 7.62 mm).

Kata Kunci : Vanillin; Chalcone; Pyrazoline; Antibacterial