1. Cerebroside C increases tolerance to chilling injury and alters lipid composition in wheat roots
Hong-Xia Li, Yu Xiao, Ling-Ling Cao, Xu Yan, Cong Li, Hai-Yan Shi, Jian-Wen Wang, Yong-Hao Ye PLoS One. 2013 Sep 13;8(9):e73380. doi: 10.1371/journal.pone.0073380. eCollection 2013.
Chilling tolerance was increased in seed germination and root growth of wheat seedlings grown in media containing 20 µg/mL cerebroside C (CC), isolated from the endophytic Phyllosticta sp. TG78. Seeds treated with 20 µg/mL CC at 4 °C expressed the higher germination rate (77.78%), potential (23.46%), index (3.44) and the shorter germination time (6.19 d); root growth was also significantly improved by 13.76% in length, 13.44% in fresh weight and 6.88% in dry mass compared to controls. During the cultivation process at 4 °C for three days and the followed 24 h at 25 °C, lipid peroxidation, expressed by malondialdehyde (MDA) content and relative membrane permeability (RMP) was significantly reduced in CC-treated roots; activities of lipoxygenase (LOX), phospholipid C (PLC) and phospholipid D (PLD) were inhibited by 13.62-62.26%, 13.54-63.93% and 13.90-61.17%, respectively; unsaturation degree of fatty acids was enhanced through detecting the contents of CC-induced linoleic acid, linolenic acid, palmitic acid and stearic acid using GC-MS; capacities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were individually increased by 7.69-46.06%, 3.37-37.96%, and -7.00-178.07%. These results suggest that increased chilling tolerance may be due, in part, to the reduction of lipid peroxidation and alternation of lipid composition of roots in the presence of CC.
2. [Investigation on secondary metabolites of endophytic fungus Talaromyces purpurogenus hosted in Tylophora ovate]
Jing-Yi Zhao, Zhen Liu, Sen-Feng Sun, Yun-Bao Liu Zhongguo Zhong Yao Za Zhi. 2020 Mar;45(6):1368-1373. doi: 10.19540/j.cnki.cjcmm.20191204.201.
Eight compounds,(R)-2-[5-(methoxycarbonyl)-4-methyl-6-oxo-3,6-dihydro-2H-pyran-2-yl]acetic acid(1),(3S,4R)-3,4-dihydro-3,4-epoxy-5-hydroxynaphthalen-1(2H)-one(2),(-)-mitorubrinol(3),(-)-mitorubrin(4),(±)-asperlone A(5), terreusinone(6), verrucisidinol(7) and cerebroside C(8) were isolated from the endophytic fungus Talaromyces purpurogenus by using various column chromatographic techniques. Their structures were identified by NMR, MS, CD and optical rotation. Compounds 1 and 2 were new compounds. Their anti-diabetic activities in vitro were evaluated, and compound 1 showed moderate inhibitory activity toward XOD at 10 μmol·L~(-1) with the inhibition rate of 69.9%.
3. [Antibacterial secondary metabolites of Clonostachys rosea, an endophytic fungus from Blumea balsamifera (L.) DC]
Xuechun Shu, Yingbo Zhang, Lingliang Guan, Zhenxia Chen, Mei Huang, Xiaolu Chen, Yuan Yuan, Chao Yuan Sheng Wu Gong Cheng Xue Bao. 2020 Aug 25;36(8):1650-1658. doi: 10.13345/j.cjb.190555.
Endophytic fungus is an important treasure trove for discovery of structurally unusual and biologically diverse compounds. A phytochemical investigation on a fungus Clonostachys rosea inhabits inner tissue of Blumea balsamifera (L.) DC. was initiatedrecently in our lab. Six pure compounds were isolated through silica gel column chromatography, sephadex LH-20, and semi-preparative HPLC techniques, with bio-guided strategy. Their structures were characterized as verticillin A (1), (S)-(+)-fusarinolic acid (2), 8-hydroxyfusaric acid (3), cerebroside C (4), 3-Maleimide-5-oxime (5), and bionectriol A (6) by analyses of NMR and MS data. All compounds were tested in vitro antibacterial activities against four strains of bacteria, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa, and results revealed that 1, 4 and 6 display notableinhibition againstthree bacteria, with MIC values ranging from 2 to 16 μg/mL. Our findings provide references for mining novel antibiotics from endophytes originated from Li Minority medicinal plant B. balsamifera (L.) DC.