Bioactive 7-Oxabicyclic[6.3.0]lactam and 12-Membered Macrolides from a Gorgonian-Derived Cladosporium sp. Fungus

One new bicyclic lactam, cladosporilactam A (1), and six known 12-membered macrolides (2–7) were isolated from a gorgonian-derived Cladosporium sp. fungus collected from the South China Sea. Their complete structural assignments were elucidated by comprehensive spectroscopic investigation. Quantum chemistry calculations were used in support of the structural determination of 1. The absolute configuration of 1 was determined by calculation of its optical rotation. Cladosporilactam A (1) was the first example of 7-oxabicyclic[6.3.0]lactam obtained from a natural source. Compound 1 exhibited promising cytotoxic activity against cervical cancer HeLa cell line with an IC₅₀ value of 0.76 μM.     

Rare Chromones from a Fungal Mutant of the Marine-Derived Penicillium purpurogenum G59

Three new and rare chromones, named epiremisporine B (2), epiremisporine B1 (3) and isoconiochaetone C (4), along with three known remisporine B (1), coniochaetone A (5) and methyl 8-hydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylate (6) were isolated from a mutant from the diethyl sulfate (DES) mutagenesis of a marine-derived Penicillium purpurogenum G59. The structures of 2–4 including the absolute configurations were determined by spectroscopic methods, especially by NMR analysis and electronic circular dichroism (ECD) experiments in conjunction with calculations. The absolute configuration of the known remisporine B (1) was determined for the first time. Compounds 2 and 3 have a rare feature that has only been reported in one example so far. The compounds 1–6 were evaluated for their cytotoxicity against several human cancer cell lines. The present work explored the great potential of our previous DES mutagenesis strategy for activating silent fungal pathways, which has accelerated the discovery of new bioactive compounds.     

Alkaloids with Cardiovascular Effects from the Marine-Derived Fungus Penicillium expansum Y32

Three new alkaloids (1, 4 and 8), together with nine known analogues (2, 3, 5–7, and 9–12), were isolated from the marine-derived fungus Penicillium expansum Y32. Their structures including the absolute configurations were elucidated by spectroscopic and Mosher’s and Marfey’s methods, along with quantum electronic circular dichroism (ECD) calculations. Each of the compounds was evaluated for cardiovascular effects in a live zebrafish model. All of the compounds showed a significant mitigative effect on bradycardia caused by astemizole (ASM) in the heart rate experiments. Compounds 4–6 and 8–12 exhibited potent vasculogenetic activity in vasculogenesis experiments. This is the first study to report that these types of compounds show cardiovascular effects in zebrafish. The results suggest that these compounds could be promising candidates for cardiovascular disease lead compounds.     

杀菌型乳酸菌饮料的模糊数学综合感官评判方法

通过对市场上流行的5种杀菌型乳酸菌饮料的焦糖味、果味、发酵味、甜味、酸味、涩感的感官评定,采用组合赋权法得出杀菌型乳酸菌饮料焦糖味、果味、发酵味、甜味、酸味、涩感的质量权重.对5种杀菌型褐色乳酸菌饮料各指标以权重,然后结合模糊数学综合评判方法,得出模糊关系曲线.结果表明:5种杀菌型乳酸菌饮料的整体感官排序为:样品5＞样品2＞样品4=样品l＞样品3,与一般排序法所得结果样品2＞样品4=样品1＞样品5＞样品3相比较稍有不同.因此,模糊数学综合评判方法比常用的排序法更科学、合理、客观.     

The endophytic fungus Piriformospora indica protects wheat from fusarium crown rot disease in simulated UK autumn conditions

The root endophytic fungus Piriformospora indica (Sebacinacea) forms mutualistic symbioses with a broad range of host plants, increasing their biomass production and resistance to fungal pathogens. This study evaluated the effect of P. indica on fusarium crown rot disease of wheat, under in vitro and glasshouse conditions. Interaction of P. indica and Fusarium isolates under axenic culture conditions indicated no direct antagonistic activity of P. indica against Fusarium isolates. Seedlings of wheat were inoculated with P. indica and pathogenic Fusarium culmorum or F. graminearum and grown in sterilized soil‐free medium or in a non‐sterilized mix of soil and sand. Fusarium alone reduced emergence and led to visible browning and reduced root growth. Roots of seedlings in pots inoculated with both Fusarium isolates and P. indica were free of visible symptoms; seed emergence and root biomass were equivalent to the uninoculated. DNA was quantified by real‐time polymerase chain reaction (qPCR). The ratio of FusariumDNA to wheat DNA rose rapidly in the plants inoculated with Fusarium alone; isolates and species were not significantly different. Piriformospora indica inoculation reduced the ratio of Fusarium to host DNA in the root systems. The reduction increased with time. The ratio of P. indica to wheat DNA initially rose but then declined in root systems without Fusarium. With Fusarium, the ratio rose throughout the experiment. The absolute amount of FusariumDNA in root systems increased in the absence of P. indica but was static in plants co‐inoculated with P. indica.     

Suppression of Meloidogyne incognita by the endophytic fungus Acremonium implicatum from tomato root galls

Specific endophytes with biocontrol potential might occur in diseased plant tissues. We isolated an endophytic fungus from tomato root galls infected with Meloidogyne incognita and identified it as Acremonium implicatum based on morphology and internal transcribed spacer sequences. Its biocontrol potential was tested in vitro and in pot and field experiments. In the in vitro test, 96.0% of second-stage juveniles of M. incognita were killed by a culture filtrate of A. implicatum after 48 h. The fungus also suppressed egg hatching, with only 36.3% of treated eggs hatching compared with 87.3% of control eggs. Pot experiments showed that A. implicatum inhibited the formation of root galls, with 40.6 galls per treated plant compared with 121.6 on control plants. A. implicatum reduced the nematode population in soil, with 151.1 nematodes per 100 g treated soil and 375.1 in control soil. Field experiments demonstrated that the root gall index of treated plants (25) was markedly lower than that of control plants (96). In conclusion, A. implicatum has excellent potential for the biocontrol of M. incognita.     

食线虫真菌蠕虫埃斯特菌对植物寄生线虫的侵染特性

为评价食线虫真菌蠕虫埃斯特菌Esteya vermicola菌株NKF 13222的生防应用价值,采用2%水琼脂培养基平板接种法测定了该菌株对7种植物寄生线虫的诱引、黏附和侵染能力,并比较了其对不同线虫的侵染特性.结果显示,该菌株的菌丝对松材线虫、拟松材线虫、腐烂茎线虫和水稻干尖线虫均有诱引作用,而对南方根结线虫、禾谷孢囊线虫和穿刺短体线虫无诱引作用;菌株的粘性分生孢子对有诱引现象的4种线虫都能黏附,接种24 h后的黏附率达到82%～99%,对无诱引现象的3种线虫不能黏附;粘性分生孢子黏附虫体后对不同线虫的侵染力存在差异,接种7 d后的松材线虫死亡率可达98%,而拟松材线虫、腐烂茎线虫和水稻干尖线虫死亡率分别为43%、35%和9%.表明蠕虫埃斯特菌不仅是松材线虫的强内寄生真菌,而且对其它重要植物寄生线虫也具有一定的应用潜力.     

双孢蘑菇液氮保藏菌株的遗传稳定性分析

双孢蘑菇As2796、As3003、As4607、As4580等4个菌株经4年的液氮保藏,菌种解冻后进行成活率的测定,恢复生长的菌种在粪草培养基上进行不同温度、不同含水量及不同酸碱度的走菌试验,同时进行纤维素酶活力的测定、同工酶谱检测、RAPD检测及出菇栽培等试验。试验结果表明：双孢蘑菇菌种在液氮中经过4年的保藏,液氮保藏菌种的菌丝生长速度、纤维素酶活力与对照菌株相同,同工酶电泳酶谱和RAPD扩增条带保持不变,栽培出菇仍保持着原有的生长特性与产质量性状,液氮保藏方法可以长期保持双孢蘑菇菌种的稳定性。     

采用人工方法改善黑木耳生长的小气候环境效应研究

针对辽西半干旱地区黑木耳栽培因温度、湿度过高或过低造成的产低质劣问题,通过观测分析人工调控方法的小气候环境效应,为高产优质栽培黑木耳提供改善小气候环境方面的理论依据。按适宜黑木耳生长的小气候环境指标,及时采取不同人工方法调控改善黑木耳生长的小气候环境,可避免或减少由于小气候环境不适宜造成的黑木耳产低质劣现象。盖草帘能降低极端最高温度25~30℃,帘下灌水能降低极端最高温度6℃左右,盖塑料薄膜后极端最高温度能增加10~12℃,喷水可增湿60%左右,通风可降湿12%~20%。通过人工调控方法能使黑木耳生长在比较适宜的小气候环境内,提高了黑木耳的品质和产量。