| In the past,because of the pathogenic fungi is difficulty to colonize and grow in the human body.so invasive fungal infection is infrequent.On the other hand,the pathogenic fungi share some of cellular structure with body cell.so In comparison with antibiotics and antiviral drugs,the development of antifungal drug is more difficulty.So,there is few antifungal drug in clinical,in the meantime,toxic side effects are extremely.Nowadays,with the increase of the AIDS patients and cancer patients and the the widespread use of anti-tumor drugs.Invation fungal infection rate and mortality rate is increasing year by year.Therefore,looking for new antifungal drugs is imminent.At present,due to technical constraints,chemical synthesis of drug research and development rate is declining.So natural compounds will be the new direction of new drug research and development.Plant endophytic fungi symbiotic with plants tend to carry certain genes of the host,instead of the host to synthesize some active substances,such as some of the endophytic fungi in yew can synthesize paclitaxel.Therefore,the secondary metabolites of plant endophytes are a huge resource repository.The diversity of the environment gave birth to biological diversity,and the diversity of organisms gave birth to chemical diversity.In this study,27 plants were collected from different latitude and longitude regions,and the endophytic fungi were isolated from plants.There were 13 genera and 372 fungi.The results showed that the three fungi could inhibit the growth of Candida albicans,and the two fungi had the inhibitory effect on Candida albicans,and the antifungal activity of the strain BC177 was the highest.Strong.Strain BC177 was subjected to solid fermentation extraction and re-screened with a MIC of 160 ?g/m L for Candida albicans.In order to further investigate the inhibitory effect of the secondary metabolite of strain BC177 on Candida albicans,the inhibitory curve of the secondary metabolite of strain BC177 against white lethal yeast was obtained by XTT reduction method.The MIC value of the sample on Candida albicans biofilm was 82.30?g/m L,and the inhibitory effect increased with the increase of the concentration.The single stage analysis and orthogonal test were used to optimize the shake stage of strain BC177 for large scale fermentation.The optimum culture conditions were as follows: the carbon source was potato flour,the nitrogen source was peptone,the initial p H was 7,and the 1× 107CFU/m L spore suspension was inoculated with 10 m L.The culture temperature and culture time were 28? and 3d The secondary metabolites were isolated by column chromatography,and eight components were obtained.The activity of component S5 was the strongest and the MIC value of Candida albicans was 40?g/m L.The purity of the component S5 was 90.47,and its molecular weight was 352 by mass spectrometry.Finally,the inhibitory effect of the active component on the proliferation of SW480 colon cancer cells in vitro was investigated.When the concentration of the samples was in the range of 20-100?g/m L,the SW480 colon cancer cells were inhibited and dose-dependent,the half lethal concentration is 64.81?g/m L.In this study,we obtained a strain with antifungal activity and antitumor activity,which provided a new direction for the development of new drugs. |
PDF Full Text Request