The aims of this study were the analysis of the secondary metabolites and evaluation of the
antibacterial and antifungal activity of Alternaria alternata. Twenty six bioactive compounds were
identified in methanolic extract of Alternaria alternata. The identification of bioactive chemical
compounds is based on the peak area, retention time molecular weight and molecular formula. GC-MS
analysis of A. alternata revealed the existence of the ?-acetyl-L-serine, 2(5H)-furanone, 6-oxabicyclo[
3.1.0]hexan-3-one, D-glucose,6-O-?-D-GALACTOPYRANOSYL, DL-arabinose, ?-N-fommyl-Llysine,
2-[4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid) (HEPES), thrietol, 2-O-heptyl, 2-deoxy-2-
fluoro-1,6-anhydro-?-d-glucopyranose, d-ribo-hexos-3-ulose, ?-D-glucopyranoside, O-?-Dglucopyranosyl-(
1.fwdarw.3)-?-D-fru, maltose, 4H-pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl,
desulphosinigrin, uric acid, midazole-4-carboxylic acid, 2-fluoro-1-methoxymethyl-ethyl ester, geranyl
isovalerate, 1-nitro-?-d-arabinofuranose, tetraacetate, glycyl-D-asparagine, ?-D-xylofuranose, cyclic
1,2:3,5-bis(butylboronate), estra -1,3,5(10)-trien-17?-ol, glucobrassicin, N-2,4-Dnp-L-arginine,
dasycarpidan-1-methanol, acetate(ester) and 5alpha-androstane-3,17-monooxime. The fourier transform
infrared (FTIR) analysis of A. alternata proved the presence of aromatic rings, aliphatic fluoro
compounds, tetiary amine, C-N stretch, ammonium ions, organic nitrate, methylene-CH. asym, and
normal polymeric O-H stretch which shows major peaks at 711.73, 846.57, 873.75, 1026.13, 1149.57,
1205.51, 1238.30, 1409.96, 1631.78, 2517.10, 2854.65, 2924.09, 3059.75 and 3271.27. A. alternate had
maximum zone formation (5.04 ± 0.29) mm against Klebsiella pneumonia.