Wen‐Zhi Shi, Xue‐Qiong Yang, Hai-Li Han, Hua Xu, Zhong-Jun Zeng, Ya‐Bin Yang, Le Cai, Zhong‐Tao Ding
Sixteen new secondary metabolites, including one unprecedented 2-butylresorcinol-ketone hybrid ( 1 ) with 6/6/5/6 tetra-cyclic benzannulated spiroketal scaffold, two xyloketal analogues 2 and 3 with an unique 5,6-dihydro-2 H -pyran-2-one residue, one caryophyllene sesquiterpene ( 4 ), three C 10 polyketides ( 6, 7, 9 ), four γ-lactone derivatives ( 12, 14 – 16 ), one unusual botryodiplodin-hydroxy ketone hybrid ( 17 ), and four unusual C 10 polyketide-botryodiplodin hybrids ( 19 – 22 ) were isolated from Paris polyphylla endophyte, Nigrospora lacticolonia . Their structures were identified mainly by NMR, ECD, and X-ray crystallography. The biosynthetic pathway of 1 was proposed. Compounds 6 – 8, 12, 17, 19, and 21 demonstrated significant antiphytopathogenic activities against Fusarium oxysporum, comparable to nystatin. Most compounds exhibited growth-promoting effects on rice seeds under F. oxysporum, salinity, and cold stresses. At 100 μg/mL, compounds 3 and 16 exhibited insecticidal activities with mortality rates of 55.0% and 48.3%, respectively. Significantly, compound 3 showed plant resistance against phytopathogens, salt stress, and insecticidal activity. The structure–activity relationship was also discussed.