A total of 96 isolates were obtained from 375 segments, isolated from the healthy roots, stems, leaves, hypocotyls and flowers of Bruguiera sexangula (Lour.) Poir. collected at the Dong Zhai Gang Mangrove Garden on Hainan Island, and 20 independent representative isolates were identified using a combination of morphological and molecular approaches. The most frequent endophytic fungal species isolated were Diaporthe phaseolorum (relative frequency = 31.2%). The Shannon–Wiener diversity and Simpson’s diversity index both showed that stems possessed the highest diversity compared to the other tissues estimated. Ethyl acetate extracts and the isolated metabolites were tested for antimicrobial activity using the serial dilution technique and for antioxidant activity using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) radical-scavenging capacity assays, respectively. The fungal isolate HL18 ( Gelasinospora endodonta ) cultured on Czapek’s agar (CA) displayed a broad spectrum of antimicrobial activities and was significantly active against Escherichia coli (MIC = 0.0625 mg ml −1 ). Antioxidant assays showed that most of the fungal isolates (60.0%) exhibited some degree of antioxidant capacity (%RSA > 50%). The stain HL14 ( Pestalotiopsis mangiferae ) grown on potato dextrose agar (PDA) exhibited the highest DPPH and ABTS radical-scavenging capability with IC 50 values of 0.717 ± 0.012 mg ml −1 and 0.787 ± 0.027 mg ml −1 , respectively. Furthermore, five known secondary metabolites 1–5 were isolated and identified from HL-14. Compounds 1 and 5 exhibited weak antioxidant activity.

中文翻译：

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系统发育多样性、抗菌和抗氧化潜力以及来自与红树林 Bruguiera sexangula (Lour.) Poir 相关的可培养内生真菌的生物活性化合物的鉴定。

从 Bruguiera sexangula (Lour.) Poir 的健康根、茎、叶、下胚轴和花中分离得到 375 个片段，共获得 96 个分离株。在海南岛东寨岗红树林花园收集，并使用形态学和分子方法的组合鉴定了 20 个独立的代表性分离株。分离出的最常见的内生真菌物种是 Diaporthe phaseolorum（相对频率 = 31.2%）。香农-维纳多样性和辛普森多样性指数都表明，与估计的其他组织相比，茎具有最高的多样性。使用连续稀释技术测试乙酸乙酯提取物和分离的代谢物的抗微生物活性，并使用 2,2'-二苯基-1-苦基肼 (DPPH) 和 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) 自由基清除能力测定，分别。在 Czapek 琼脂 (CA) 上培养的真菌分离物 HL18 (Gelasinospora endodontta) 显示出广谱的抗微生物活性并且对大肠杆菌具有显着活性 (MIC = 0.0625 mg ml -1 )。抗氧化分析表明，大多数真菌分离物 (60.0%) 表现出一定程度的抗氧化能力 (%RSA > 50%)。在马铃薯葡萄糖琼脂（PDA）上生长的染色剂HL14（Pestalotiopsis mangiferae）表现出最高的DPPH和ABTS自由基清除能力，IC 50 值分别为0.717 ± 0.012 mg ml -1 和0.787 ± 0.027 mg ml -1 。此外，从 HL-14 中分离并鉴定了五种已知的次级代谢物 1-5。化合物1和5表现出较弱的抗氧化活性。