Study On Secondary Metablites From Two Endophytic Fungi Pestalotiopsis Sp. And Their Activities

Twenty-four compounds （including seven new ones） were isolated and purified fromPestalotiopsis photiniae and Pestalotiopsis zonata by using various chromatographic methods（silica gel column chromatography, preparative thin-layer chromatography, gel chromato-graphy and preparative HPLC）. Their structures were elucidated by extensive spectroscopicanalysis （1D and2D-NMR、MS、IR、UV）.Nineteen compounds were obtained from the fermentation broth of the strain Pestalotiopsisphotiniae. Four eremophilane-type sesquiterpenoids were isolated from this genus for the firsttime and named as: dihydroberkleasmin A（1），berkleasmin C（2），Pestalotiopin A（3），Pestalotiopin B（4）. Compounds （1）、（3）、（4） were new ones. In addition,9phthalidederivatives were obtained. Among them,5-（3’-methyl-2’-butenyl）-2-hydroxy-3-methoxy-4-methylbenzoic acid （5）,5-（3’-carboxyl-3’-methyl-2′E-allyloxy）-3-methoxy-4-methyl phth-alid（6） and5-（3’,3’-dimethylallyloxy）-2-methoxy carbonyl-3-methoxy-4-methylbenzoic acid（7） are new compounds. The9phthalide derivatives were evaluated for antifungal activitiesagainst three plant pathogenic fungi: Fusarium graminearum, Botrytis cinerea, andPhytophthora nicotianae, with MIC values from3.1to50.0μg/ml （the positive controlketoconazole showed MIC values are3.1μg/ml）. We tested their antitumor activity, usingCAM model. Compound （8） exhibited definite antitumor activity, and the inhibition ratioreached32.53%～43.14%within the concentration range of10μg/ml～100μg/ml.Six compounds were obtained from the fermentation broth of the strain Pestalotiopsiszonata, including a new biphenyl compound, named as2’-acetyl-4’,4-dimethoxybiphenyl-2-carbaldehyde（20）. It showed weak activity towards the bacteria Escherichia coli,Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, methicillinresistant Staphylo-coccus aureus, Acinetobacter baumannii and vancomycin-resistantEnterococcus faecium, and their IC₅₀values were0.75,0.75,0.82,0.81,0.84,0.90and0.87μg/ml。...