TY - JOUR
T1 - Endophytic fungi from Nerium oleander L (Apocynaceae)
T2 - Main constituents and antioxidant activity
AU - Huang, Wu Yang
AU - Cai, Yi Zhong
AU - Hyde, Kevin D.
AU - Corke, Harold
AU - Sun, Mei
N1 - Funding Information:
Acknowledgments This research was supported by grants from the University of Hong Kong (Seed Funding for Basic Research). We thank staff of Kadoorie Farm and Botanic Garden for assisting in plant sample collection, Dr L. Cai of the University of Hong Kong for assistance in identifying endophytic fungi, and Dr. Jie Xing of Republic Polytechnic, Singapore, for helping with LC-ESI-MS and GC-MS analyses.
PY - 2007/9
Y1 - 2007/9
N2 - Diverse endophytic fungi exist within plant aerial tissues, with a global estimate of up to a million undescribed species. These endophytes constitute a rich bio-resource for exploration to discover new natural products. Here we investigate fungal endophytes associated with a medicinal plant, Nerium oleander L. (Apocynaceae). A total of 42 endophytic fungal strains were isolated from the host plant. Total antioxidant capacity, xanthine oxidase inhibitory activity, antimicrobial activity, and total phenolic content (TPC) were evaluated for 16 representative fungal cultures grown in improved Czapek's broth and for the host plant. The total antioxidant capacities and phenolic contents of the fungal cultures ranged from 9.59 to 150.79 μmol trolox/100 mL culture, and from 0.52 to 13.95 mg gallic acid/100 mL culture, respectively. The fungal culture of an endophytic strain Chaetomium sp. showed the strongest antioxidant capacity, contained the highest level of phenolics, and to some extent inhibited xanthine oxidase activity with an IC50 value of 109.8 μg/mL. A significant positive correlation was found between antioxidant capacity and TPC in the tested samples. Most of the endophytic fungal cultures tested have a wide range of antimicrobial activities, which were not very strong, but much better than those of the host plant. The major bioactive constituents of the fungal cultures were investigated using LC-ESI-MS and GC-MS, and preliminary identification detected phenolics (e.g. phenolic acids and their derivatives, flavonoids) and volatile and aliphatic compounds. This study shows that the endophytic fungi isolated from N. oleander can be a potential antioxidant resource.
AB - Diverse endophytic fungi exist within plant aerial tissues, with a global estimate of up to a million undescribed species. These endophytes constitute a rich bio-resource for exploration to discover new natural products. Here we investigate fungal endophytes associated with a medicinal plant, Nerium oleander L. (Apocynaceae). A total of 42 endophytic fungal strains were isolated from the host plant. Total antioxidant capacity, xanthine oxidase inhibitory activity, antimicrobial activity, and total phenolic content (TPC) were evaluated for 16 representative fungal cultures grown in improved Czapek's broth and for the host plant. The total antioxidant capacities and phenolic contents of the fungal cultures ranged from 9.59 to 150.79 μmol trolox/100 mL culture, and from 0.52 to 13.95 mg gallic acid/100 mL culture, respectively. The fungal culture of an endophytic strain Chaetomium sp. showed the strongest antioxidant capacity, contained the highest level of phenolics, and to some extent inhibited xanthine oxidase activity with an IC50 value of 109.8 μg/mL. A significant positive correlation was found between antioxidant capacity and TPC in the tested samples. Most of the endophytic fungal cultures tested have a wide range of antimicrobial activities, which were not very strong, but much better than those of the host plant. The major bioactive constituents of the fungal cultures were investigated using LC-ESI-MS and GC-MS, and preliminary identification detected phenolics (e.g. phenolic acids and their derivatives, flavonoids) and volatile and aliphatic compounds. This study shows that the endophytic fungi isolated from N. oleander can be a potential antioxidant resource.
KW - Antimicrobial activity
KW - Antioxidant activity
KW - Apocynaceae
KW - Endophytic fungi
KW - Nerium oleander
KW - Total phenolic content
KW - Xanthine oxidase inhibition
UR - http://www.scopus.com/inward/record.url?scp=34547828035&partnerID=8YFLogxK
U2 - 10.1007/s11274-007-9357-z
DO - 10.1007/s11274-007-9357-z
M3 - 文章
AN - SCOPUS:34547828035
SN - 0959-3993
VL - 23
SP - 1253
EP - 1263
JO - World Journal of Microbiology and Biotechnology
JF - World Journal of Microbiology and Biotechnology
IS - 9
ER -