Helvolic Acid, A Secondary Metabolite Produced by Neosartorya spinosa KKU-1NK1 and Its Biological Activities
Wareerat Sanmanoch [a], Wiyada Mongkolthanaruk [a], Somdej Kanokmedhakul [b], Tadanori Aimi [c] and Sophon Boonlue *[a, b]* Author for corresponding; e-mail address: bsopho@kku.ac.th
Volume: Vol.43 No.3 (APRIL 2016)
Research Article
DOI:
Received: 17 June 2015, Revised: -, Accepted: 27 October 2015, Published: -
Citation: Sanmanoch W., Mongkolthanaruk W., Kanokmedhakul S., Aimi T. and B] S.B.[., Helvolic Acid, A Secondary Metabolite Produced by Neosartorya spinosa KKU-1NK1 and Its Biological Activities, Chiang Mai Journal of Science, 2016; 43(3): 484-494.
Abstract
Helvolic acid, an antimicrobial metabolite was isolated from the crude ethyl acetate extract of the soil fungus [A1] Neosartorya spinosa KKU-1NK1. The isolated helvolic acid inhibited growth of[A2] Gram positive [A3] pathogenic bacteria (Methicillin-resistant Staphylococcus aureus DMST 20654, Staphylococcus aureus ATCC 25923, Staphylococcus saprophyticus ATCC 15305, Streptococcus pneumonia DMST 15319, Enterococus faecalis ATCC 29212 and Bacillus subtilis ATCC 6633) and Gram negative [A4] plant pathogenic bacteria (Ralstonia solanacearum, Xanthomonas campestris pv. vesicatoria) with the MIC ranging from 16-32 µg/ml. It also showed an unprecedented antimicrobial activity against Mycobacterium tuberculosis H37Ra strain with the MIC ranging from 12.5-25.0 [KKU5] µg/ml. In addition, the result of time kill assay revealed that helvolic acid was bacteriostatic, which inhibited the growth of pathogenic bacteria at 2 fold of MIC. As a result of irregular-shaped cell division was observed by scanning electron microscopy.