| Endophytes, a rich source of bioactive products, are one of the hot topics of research owing to their potential interesting and biological activities. Because of its unique living environment, endophytic fungus may produce special metabolites with unusual chemical structure to adapt the living condition. And a lot of bioactive metabolites have been derived from endophytic fungi.Camptotheca acuminata, a medicinal plant specifically distributed in China, is rich in the anticancer compound camptothecin, with the highest distribution in the new leaf of up to 0.4%. In such a special living environment, special endophytic fungi may exist. Meanwhile, endophytic fungi in C. acuminata may take part in the synthesis or transformation of camptothecin. Therefore, it is important to study bioactive components of the endophytic fungi isolated from C. acuminata.Secondary metabolites from endophytic fungus NXZ-05, which was isolated from the pharmaceutical plant, Camptotheca acuminate, were observed in this study. After comparing the bioactivities of the extracts cultivated in PDA, Czapek and GPY, Solid-state fermentation was performed on strain NXZ-05 with PDA media for 14 d at 25 oC. Employing different isolation and purification methods, eight compounds were obtained. In this work, we report the isolation, structure elucidation and bioactivities of the eight compounds, six of which were new (T3, T5, T13, T17, T30, T31). The strain NXZ-05 was identified to be Phomopsis sp. according to its ITS sequence of rDNA (ITS1-5.8S-ITS2). In the eight compounds, five of them belonged to ten-membered lactones(T1, T3, T5, T13, T17) , T1 was multiplolide A,T3 was 8-O-acetyl 5,6-dihydro-5,6-epoxymultiplotide A,T5 was 8-O-acetyl multipolide A,T13 was 5,6-dihydro-5,6-epoxymultiplotide A and T17 was 3,4-deo xy-3,4-didehyd- romultiplodide A. Two of the eight compounds belonged to unsaturated fatty acid [T31: (4E)-6,7,9-trihydroxy-4-decenoic acid; and T30, the methyl ester of T31, met- hyl (4E)-6,7,9-trihydroxy-4-decenoate]. And T20 was ergosterol peroxide.All compounds were studied for their bioactivities, including AChE inhibitory activities, antimicrobial, anti-tumor, and antioxidant activities. T5 exhibited distinct inhibitory activity against AChE with the IC50 value at 5.7μmol/L compared with the positive control galanthamine (with the inhibitory rate 94.8% at 2.5μg/mL). Compounds T1, T3, T5 and T13 showed moderate antimicrobial activities against Mycobacterium tuberculosis with the MIC values at 25μg/mL, while no evident antimicrobial activities against Candida albicans, Saccharomyces cerevisiae, Bacillus subtilis, Escherichia coli, Staphlococcus aureus were shown. T1 and T20 exhibited moderate anti-tumor activity against Raji and Hela cell line with the IC50 value at 0.5μmol/mL and 0.1μmol/mL, respectively. None of the compounds showed antioxidant activities.Furthermore, we compared the broth of NXZ-05 cultivated in GPY,YES,GPM,PD and Sabouraud with submerged fermentation. And the broth of GPY exhibited the most distinct antitumor activity with the inhibitory rate 99.4% at 50μg/mL against Raji cell line compared with the inhibitory rate less than 40% for the rest broth.Our study indicated that metabolites from strain NXZ-05 were worth to be researched in-depth. Compound T5 had the potentiality to be a leading compound of new drug for Alzheimer's disease therapy.
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