Cholinesterase inhibitor (Altenuene) from an endophytic fungus Alternaria alternata: optimization, purification and characterization

• Published in: Journal of applied microbiology Vol. 121; no. 4; pp. 1015 - 1025
• Main Authors: Bhagat, J., Kaur, A., Kaur, R., Yadav, A.K., Sharma, V., Chadha, B.S.
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.10.2016
• Subjects: acetylcholinesterase inhibitor; altenuene; Alternaria - chemistry; Alternaria - isolation & purification; Alternaria - metabolism; Alternaria alternata; Animals; antioxidant; Antioxidants; Catharanthus - microbiology; Catharanthus roseus; Cholinesterase Inhibitors - chemistry; Cholinesterase Inhibitors - isolation & purification; Cholinesterase Inhibitors - metabolism; Cholinesterase Inhibitors - pharmacology; Cholinesterases - chemistry; Cholinesterases - metabolism; Endophytes - chemistry; Endophytes - isolation & purification; Endophytes - metabolism; endophytic fungi; Fungi; Insect Proteins - antagonists & inhibitors; Insect Proteins - metabolism; insecticidal; Insecticides; Insecticides - chemistry; Insecticides - isolation & purification; Insecticides - pharmacology; Lactones - chemistry; Lactones - isolation & purification; Lactones - metabolism; Lactones - pharmacology; Neurological disorders; Spodoptera - drug effects; Spodoptera - enzymology; Vinca; Vinca rosea; antioxidant; endophytic fungi; altenuene; acetylcholinesterase inhibitor; Vinca rosea; Alternaria alternata; insecticidal
• DOI: 10.1111/jam.13192
• ISSN: 1364-5072

Aims The aim of this study was to screen endophytic fungi isolated from Vinca rosea for their potential to produce acetylcholinesterase (AChE) inhibitors. Method and Results Endophytic fungi isolated from V. rosea (Catharanthus roseus), were screened for AChE inhibitor production using Ellman's method. Maximum inhibition against AChE (78%) was observed in an isolate VS‐10, identified to be Alternaria alternata on morphological and molecular basis. The isolate also inhibited butyrylcholinesterase (73%). Significant increase (1·3 fold) was achieved after optimization of process parameters using one variable at time approach. The inhibitor was purified using chromatographic techniques. The structure elucidation of the inhibitor was carried out using spectroscopic techniques and was identified to be ‘altenuene’. The purified inhibitor possessed antioxidant potential as revealed by dot blot assay. The insecticidal potential of purified inhibitor was evaluated by feeding Spodoptora litura on diet amended with inhibitor. It evinced significant larval mortality. Conclusions Endophytic A. alternata can serve as a source of dual cholinesterase inhibitor ‘altenuene’ with significant antioxidant and insecticidal activity. This is the first report on acetylcholinestearse inhibitory activity of altenuene. Significance and Impact of the Study Alternaria alternata has the potential to produce a dual ChE inhibitor with antioxidant activity useful in the treatment of neurodegenerative disorders and in agriculture as biocontrol agent.