GC-MS ANALYSIS OF ANTI-MICROBIAL COMPOUNDS FROM ANTHERAEA MYLITTA COCOONS

The architecture of cocoons and the chemical compounds present in the cocoons play crucial role to provide protection of the pupae during metamorphosis. Insects spin a silk web as cocoon to facilitate protection and ensuring proper inner environment inside the cocoon during the metamorphosis. Such cocoons are equipped with a variety of chemical compounds which include antibacterial, antifungal, insecticidal and insect repellent etc. Tasar silk worms are wild silkworms grown on forest trees for their commercial value, are subject to harsh environmental conditions in comparison with domesticated Bombyx mori silk worms. In this study antimicrobial compounds were screened from Indian tropical wild tasar cocoons by Fourier transform infrared spectroscopy (FT-IR), Fourier transform-Raman spectroscopy (FT-Raman), Gas chromato-graphy- Mass spectrometry (GC-MS) and identified the chemical compounds by NIST05 MS Library. The wild cocoons possess active alcoholic and phenolic compounds, aromatic organic acids, alkaloids, fatty acids and their derivatives for various protective functions. This chemical defence strategy of wild cocoons was confirmed by evaluating the antimicrobial potential of methanolic extract of Antheraea mylitta cocoons (AmCE) against pathogenic bacterial strains of Escherichia coli, Staphylococcus aureus and fungal strains of Candida albicans, Aspergillus flavus. We concluded the bioactive chemical compounds of wild silkworm cocoons other than silk sericin and fibroin proteins are responsible for stability of the cocoon for long duration in wild harsh environmental conditions during metamorphosis. These bioactive compounds involved in the protection of Antheraea mylitta cocoons have been elucidated.