1、有机化学有机化学 Chinese Journal of Organic Chemistry NOTE *Corresponding author.E-mail: Received May 23,2022;revised July 11,2022;published online August 25,2022.Project supported by the Key Research and Development Program of Hainan Province(No.ZDYF2021SHFZ270),the National Natural Science Foundation of C
2、hina(Nos.32160108,41866005),the Natural Science Foundation of Hainan Province(No.220RC593),the Key Science and Technology Program of Hainan Province(No.ZDKJ202008)and the Specific Research Fund of the Innovation Platform for Academicians of Hainan Province(No.YSPTZX202030).海南省重点研发计划(No.ZDYF2021SHFZ2
3、70)、国家自然科学基金(No.32160108,41866005)、海南省自然科学基金(No.220RC593)、海南省科技攻关计划(No.ZDKJ202008)和海南省院士创新平台海南省专项(No.YSPTZX202030)资助项目.332 http:/sioc- Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences Chin.J.Org.Chem.2023,43,332337 DOI:10.6023/cjoc202205041 研究简报研究简报 红树来源真菌 Daldinia eschscholtzii H
4、J004 发酵产物中 三个新的次级代谢产物 王 斌a,b 曾尾女a,b 李杲钰a,b 肖 媚a,b 韦方芳a,b 罗由萍a,b 钮智刚a,b 黄国雷a,b 郑彩娟*,a,b(a海南师范大学化学与化工学院 热带药用资源化学教育部重点实验室 海口 571158)(b海南师范大学化学与化工学院 海南省热带药用植物化学重点实验室 海口 571158)摘要摘要 从红树来源真菌 Daldinia eschscholtzii HJ004 中分离得到 3 个新化合物以及 8 个已知化合物.通过高分辨质谱、一维和二维核磁共振波谱以及 X 射线单晶衍射数据确定了 8-乙基-7-羟基-5-羧基-2,3-二甲基色酮(
5、1)的结构.通过电子圆二色谱(ECD)量子化学计算以及圆二色谱(CD)数据与文献进行比较,确定了 felinone C(2)和螺旋霉素 G(3)的绝对构型.利用总抗氧化能力检测试剂盒(ABTS快速法)测试了所得11个化合物的自由基清除能力,其中4个化合物表现出显著的抗氧化活性,IC50值的范围为 5.57195.03 mol/L,强于阳性对照水溶性维生素 E(trolox)的抗氧化活性(IC50292.12 mol/L),具有开发为抗氧剂的潜力.关键词关键词 Daldinia eschscholtzii;色原酮;内酯类化合物;抗氧化活性 Three New Secondary Metaboli
6、tes from the Mangrove-Derived Fungus Daldinia eschscholtzii HJ004 Wang,Bina,b Zeng,Weinva,b Li,Gaoyua,b Xiao,Meia,b Wei,Fangfanga,b Luo,Youpinga,b Niu,Zhiganga,b Huang,Guoleia,b Zheng,Caijuan*,a,b(a Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education,College of Chemistry
7、 and Chemical Engineering,Hainan Normal University,Haikou 571158)(b Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province,College of Chemistry and Chemical Engineering,Hainan Normal University,Haikou 571158)Abstract Three new compounds,together with eight known compounds,were isola
8、ted from the mangrove-derived fungus Daldinia eschscholtzii HJ004.The structure of 8-ethyl-7-hydroxy-5-carboxyl-2,3-dimethylchromone(1)was extensively elucidated and characterized by HRESIMS,1D and 2D NMR,and single-crystal X-ray crystallography.The absolute configurations of felinone C(2)and helica
9、scolide G(3)were determined by using electronic circular dichroism(ECD)method or comparing circular dichroism(CD)data with the literature.The radical scavenging capabilities of the 11 compounds obtained were tested by total antioxidant capacity assay kit with a rapid ABTS method.Among them 4 compoun
10、ds exhibited stronger antioxidant activity with IC50 values range from 5.57 mol/L to 195.03 mol/L,than the positive control trolox(IC50292.12 mol/L).These results indicate that chromones have the potential values of developing antioxidants.Keywords Daldinia eschscholtzii;chromone;lactone;antioxidant
11、 activity 1 Introduction The mangrove ecosystem is an important biodiversity hotspot for prospecting new bioactive and chemical scaf-folds,including those with potential medicinal applica-tion.1-2 Moreover mangrove-derived fungi have repre-Chinese Journal of Organic Chemistry NOTE Chin.J.Org.Chem.20
12、23,43,332337 2023 Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences http:/sioc- sented a significant and potential source in the search of structurally diverse and biologically active natural prod-ucts.2-5 Especially,the genus of Daldinia has been found to produce various secondary
13、 metabolites,such as the im-munosuppressive dalesconols A and B,6 antifibrotic()-galewone,7 antioxidant daldinone B,8 antibacterial dalesindoloids A and B,9 and cytotoxic concentricolide.10 In our ongoing research on mangrove-derived fungi,11-14 some new bioactive compounds from the mangrove-derived
14、 fungus Daldinia eschscholtzii HJ004 have been found.13-14 In order to further explore bioactive com-pounds from the fungus D.eschscholtzii HJ004,we changed culture media and further conducted a chemical investigation of this strain cultured,which led to the char-acterization of three new compounds,
15、chromone 8-ethyl-7-hydroxy-5-carboxyl-2,3-dimethylchromone(1),O-contain-ing heterocyclic compound felinone C(2)and lactone hel-icascolide G(3),together with eight known compounds(411)(Figure 1).The structure of 1 was determined by its NMR spectral data and single-crystal X-ray diffraction analysis.T
16、he absolute configuration of 2 was determined by experimental and calculated electronic circular dichro-ism(ECD)method.The absolute configuration of 3 was established by comparing its circular dichroism(CD)data with the literature.Herein,we report the isolation,structure elucidation,and bioactivities of these compounds.2 Results and discussion 2.1 Structure elucidation Compound 1 was obtained as yellowish crystals,the molecular formula of 1 was established as C14H14O5 by itsHRESIMS data with eig