Calpain inhibitory flavonoids isolated from Orostachys japonicus

The n-butanol (n-BuOH) fraction of Orostachys japonicus A. Berger (Crassulaceae) significantly inhibited calpain activity. Through the activity-guided isolation from the n-BuOH fraction, herbacetin 8-O-α-D-ribopyranoside (1), kaempferol (2), quercetin (3), afzelin (4), astragalin (5), isoquercetin (6) and quercitrin (7) were obtained. Their structures were determined by spectroscopic techniques. Among them, compound 3 and 5 had significant calpain inhibitory activities.     

东海竹筴鱼的食性

以2008年5月、8月、11月和2009年2月东海灯光围网采集到的453条东海竹筴鱼为研究对象,对其胃含物进行分析,应用K-W非参数检验、卡方检验、聚类分析等方法,对不同季节和发育阶段条件下东海竹筴鱼的食性进行研究.结果表明: 东海竹筴鱼的饵料生物有124种(包括未鉴定种),浮游甲壳类和小型鱼类为其主要饵料类群.优势饵料生物依次是麦氏犀鳕(IRI%=39.2%)、长尾类糠虾幼体(IRI%=18.4%)、短尾类大眼幼体(IRI%=7.6%)和太平洋磷虾(IRI%=6.6%)等.季节和叉长对东海竹筴鱼的摄食强度均有显著影响(P<0.01),东海竹筴鱼春季摄食强度最高,而冬季最低;叉长140～159 mm的竹筴鱼摄食强度最高,叉长45~99 mm的幼鱼的摄食强度较高,其余叉长的鱼摄食强度相对较低.聚类分析结果表明,叉长100 mm是东海竹筴鱼摄食取向的拐点.东海竹筴鱼四季的平均营养级为3.51,属于低级肉食性鱼类.     

Continuous ATP Regeneration Using Immobilized Yeast Cells

Arthrobacter simplex was screened as an α-keto-δ-guanidinovalerate (ketoarginine) assimilating organism. A characteristic feature was its growth on ketoarginine as a carbon source; it began to grow after an extremely long lag. Its growth was stimulated by addition of 0.02% yeast extract to the medium.

The results indicated the transamination of arginine-α-ketoglutarate (α-KGA) and the hydrolyzing reaction of ketoarginine into α-keto-δ-aminovalerate and urea. Two intermediates, ketoarginine and α-keto-δ-aminovalerate, were isolated and identified by various procedures. Coupling of the two reactions was demonstrated in cell-free extracts of arginine-grown cells; ketoarginine formed from arginine by transamination with α-KGA was hydrolyzed directly to α-keto-δ-aminovalerate and urea. The metabolic routes of arginine in microorganisms were discussed.     

Possible Mechanism of Oxygen Activation in Linoleate Peroxidation by Fusarium Lipoxygenase

The Oxygen activating mechanism of Fusarium lipoxygenase, a heme-containing dioxygenase, was studied. The enzyme did not require any cofactors, such as H₂O₂, however, both superoxide dismutase and catalase inhibited linoleate peroxidation by Fusarium lipoxygenase. A low concentration of H₂O₂ caused a distinct acceleration in enzymatic peroxidation. These results indicate that both O₂? and H₂O₂ are produced as essential intermediates of oxygen activation during formation of linoleate hydroperoxides by Fusarium lipoxygenase. This peroxidation reaction was also prevented by scavengers of singlet oxygen (¹O₂), but not by scavengers of hydroxy 1 radical (OH). Generation of O₂? in the enzyme reaction was detected by its ability to oxidize epinephrine to adrenochrome. Moreover, the rate of peroxide formation was greater in the D₂O than in the H₂O buffer system. These results suggest that the Haber–Weiss reaction (O₂^?+H₂O₂→OH^?+OH^·+¹O₂) is taking part in linoleate peroxidation by Fusarium lipoxygenase, and the ¹O₂ evolved could be responsible for the peroxidation of linoleate. H₂O₂ produced endogenously in the enzyme reaction might act as an activating factor for the enzyme. This possible mechanism of oxygen activation can explain the absence of a need for exogenous cofactors with Fusarium lipoxygenase in contrast to an other heme-containing dioxygenase, tryptophan pyrrolase, which requires an exogenous activating factor, such as H₂O₂.     

Some Characteristics of Pseudomonas 0–3 which Utilizes Polyvinyl Alcohol

Pseudomonas 0–3 strain which was isolated from soil can grow on polyvinyl alcohol (PVA) as a sole carbon source. When 0.5 per cent of PVA (500, 1500 or 2000) was employed as the carbon source in the culture medium, PVA was almost completely lost from the culture fluid after a week and the concentration of total organic carbon measured by a TOC analyzer decreased from the initial value of about 2700 ppm to 250~300 ppm after 7~10 days culture. This bacterium was found to produce and secrete an inducible enzyme which degrade PVA. The way by which this enzyme degrades PVA was examined and the results were obtained which suggested that PVA was broken down oxidatively in a way of endowise splitting. However, the mechanism of PVA degradation has not been clarified yet. The optimum pH and temperature for enzyme activity were examined and they were 7.5~8.5 and 35~45°C, respectively. Morphological and biological characteristics of this bacterium were examined and it was similar to a strain of Pseudomonas boreopolis.     

Topological persistency found in aggregations of coastal sea skater,Halobates japonicus Esaki, 1924 (Hemiptera: Gerridae), based on genetic relationships amongst three aggregations in Ishigaki Island,Japan

Sea skaters, genus Halobates Eschscholtz, 1822, are the only marine insects living in mangrove beds and the tide pools of coral reefs, both of which provide dramatically variable habitats daily by virtue of tide-driven changes in surface level. Females of H. japonicus Esaki, 1924 were collected from three distinct aggregations in a single bay (24°27′5″N, 124°8′40″E) on 1–5 November 2006. Two aggregations were formed in respective tide pools of the coral reef and one was formed in the mangrove beds. Amplified fragment length polymorphism markers were used to detect the persistency of each aggregation at a mesoscale. The results suggested that H. japonicus repeatedly immigrated from outside the bay to establish a meta-population of several deme groups. Aggregations along the coastline had some persistency to the line itself and had little tendency to cross to the opposite shore, even when the distance was short.     

复合微生态制剂对幼刺参营养成分和 酶活力的影响

目的研究复合微生态制剂对幼刺参体壁营养成分、几种消化酶和免疫酶活力的影响。方法在封闭式循环系统中投喂不同的微生态制剂进行30 d刺参养殖实验。结果投喂液态复合微生态制剂组和粉状复合微生态制剂组的刺参体壁的粗脂肪、总糖、粗蛋白含量最高,两组与对照组相比差异有统计学意义(Ps0.05)。添加微生态制剂的3个实验组刺参肠道蛋白酶、淀粉酶活力均比对照组高,且差异有统计学意义(Ps0.05)。实验组刺参的肠道、体壁、体液过氧化氢酶活力均比对照组高,其中投喂液态复合微生态制剂实验组活力最高。实验组刺参组织的酸性磷酸酶和碱性磷酸酶活力也明显高于对照组(与对照组相比差异有统计学意义,Ps0.05)。结论微生态制剂可以有效改善幼刺参体壁营养成分,促进机体消化活力,提高刺参免疫力。