Abstract

Bioactives are chemical compounds often referred to as secondary metabolites. Thirty five bioactive compounds were identified in the methanolic extract of Aspergillus niger. The identification of bioactive chemical compounds is based on the peak area, retention time molecular weight and molecular formula. Gas chromatography-mass spectrometry (GC-MS) analysis of Aspergillus niger revealed the existence of the 6-Acetyl-ß-d-mannose, 4-[Dichloromethyl]-2-[[2-[1-methyl-2-pyrrolidinyl]ethyl]amino-6-trichloro, 2-Furan-carboxaldehyde,5-methyl, 2,2,2-Trifluoro-N-[2-(1-hydroxy-2,2,6,6-tetramethyl-piperidin-4-yl), 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one, HEPES (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid), Tetraacetyl-d-xylonic nitrile, Eicosanoic acid, phenylmethyl ester, Dodecanoic acid, 3-hydroxy, Desulphosinigrin, Glycyl-dl-serine, 2,5-Dimethyl-4-hydroxy-3(2H)-furanone, 2,5-Furandicarboxaldehyde, 2H-Oxecin-2-one,3,4,7,8,9,10- hexahydro-4-hydroxy-10-methyl, 6-Acetyl-ß-d-mannose, DL-Leucine, N-glycyl, 4H-Pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl, I-Gala-l-ido-octonic lactone, 2H-Pyran,tetrahydro-2-(12-pentadecynyloxy), 5-Hydroxymethylfurfural, Strychane,1-acetyl-20α-hydroxy-16-methylene, α-D-Glucopyranoside, O-α-D-glucopyranosyl-(1.fwdarw.3)ß-D-fru, Boroxin, tris(2,3-dimethylbut-2-yl), 16-Nitrobicyclo[10.4.0]hexadecane-1-ol-13-one, 3-[3-Bromophenyl]-7-chloro-3,4-dihydro-10-hydroxy-1,9(2H,10H)-a, Uric acid, 1,2,4-Trioxolane-2-octanoic acid ,5-octyl-,methyl ester, Tetraacetyl-d-xylonic nitrile, 1,2-Cyclopentanedicarboxylic acid, 4-(1,1-dimethylethyl)-,dimethyl, 2-Bromotetradecanoic acid, i-Propyl 11,12-methylene-octadecanoate, 1H-2,8a-Methanocyclopenta[a]cyclopropa [e]cyclodecan-11-one, and Octadecanoic acid. The FTIR analysis of A. niger proved the presence of aromatic rings, alkenes, aliphatic fluoro compounds, tetiary amine, C-N stretch, aromatic nitro compounds, ammonium ions and organic nitrate which shows major peaks at 696.30, 744.52, 821.68, 844.82, 900.76, 931.62, 1026.13, 1145.72, 1207.44, 1234.44, 1261.45, 1315.45, 1359.82, 1377.17, 1413.82, 1452.40, 1631.78, 1741.72, 2924.09, 3118.90, 3217.27 and 3271.27. Datura stramonium was very active against A. niger. Methanolic extract of bioactive compounds of A. niger were assayed for in vitro antibacterial activity against Pseudomonas aerogenosa, Escherichia coli, Proteus mirabilis, Staphylococcus aureus and Klebsiella pneumonia by using the diffusion method in agar. The zones of inhibition were compared with different standard antibiotics. The diameters of inhibition zones ranged from 0.46±0.1 to 6.52±0.61 mm for all treatments.

Key words: Aspergillus niger, bioactive compounds, gas chromatography-mass spectrometry, fourier-transform infrared spectroscopy.