In vitro synthesis of 20α-reduced and of 11- and 21-oxygenated steroids and their sulfates by testes of the goldfish (Carassius auratus): Testicular synthesis of corticosteroids

Testes from spermiating goldfish were incubated with [³H]17-hydroxyprogesterone. The major products in the unconjugated fraction were identified as androstenedione, androstenetrione, 11-β-hydroxyandrostenedione, 11-ketotestosterone, 17,20α-dihydroxy-4-pregnen-3-one (17,20αP) and 11-deoxycortisol. Testosterone was present predominantly in the glucuronide fraction, but yields were low (1–3%). The major components of the sulfate fraction were 17,20αP and 11-deoxycortisol. The identification of cortisone in low yield (< 2.5010) in both the free and sulfate fractions is the first report of corticosteroid biosynthesis by a teleost testis. The high yields of 17,20αP and 11-deoxycortisol and their sulphates suggests that their possible role in spermiation of the goldfish should be further investigated.     

硫酸钾复合肥应用试验

西宁市郊粮油作物施用化肥成份单一,不注重钾肥的施入,使NPK比例失调,许多粮油作物造成倒伏减产,投入高、收益低,施用硫酸钾复合肥可减少其它肥料用量,降低成本取得良好的产量与经济效益。     

Antidiabetic Activity of Differently Regioselective Chitosan Sulfates in Alloxan-Induced Diabetic Rats

The present study investigated and compared the hypoglycemic activity of differently regioselective chitosan sulfates in alloxan-induced diabetic rats. Compared with the normal control rats, significantly higher blood glucose levels were observed in the alloxan-induced diabetic rats. The differently regioselective chitosan sulfates exhibited hypoglycemic activities at different doses and intervals, especially 3-O-sulfochitosan (3-S). The major results are as follows. First, 3,6-di-O-sulfochitosan and 3-O-sulfochitosan exhibited more significant hypoglycemic activities than 2-N-3, 6-di-O-sulfochitosan and 6-O-sulfochitosan. Moreover, 3-S-treated rats showed a more significant reduction of blood glucose levels than those treated by 3,6-di-O-sulfochitosan. These results indicated that –OSO₃⁻ at the C3-position of chitosan is a key active site. Second, 3-S significantly reduced the blood glucose levels and regulated the glucose tolerance effect in the experimental rats. Third, treatment with 3-S significantly increased the plasma insulin levels in the experimental diabetic rats. A noticeable hypoglycemic activity of 3-S in the alloxan-induced diabetic rats was shown. Clinical trials are required in the future to confirm the utility of 3-S.     

混合金属盐对水稻秸秆热裂解特性的影响

为研究金属盐对水稻秸秆热裂解特性的影响,在Li2CO3-Na2CO3-K2CO3(LNK碳酸盐)中分别添加氯化盐和硫酸盐与水稻秸秆干混,采用热重分析与傅里叶变换红外光谱联用技术(thermogravimetric analyzer coupled with Fourier transform infrared spectrometry,TG-FTIR)研究了水稻秸秆的热裂解过程,并使用Coats-Redfern法计算了热裂解过程的动力学参数。结果表明:在LNK碳酸盐作用下,热裂解的活化能降低。与添加硫酸盐相比,氯化盐作用下热裂解活化能更低,热裂解反应更易进行。与纯水稻秸秆热裂解相比,LNK碳酸盐能使CO、CH4、苯酚、甲苯、甲酸和水等的浓度明显下降,而CO2浓度显著上升。在LNK碳酸盐基础上,氯化盐和硫酸盐均能促进水稻秸秆热裂解产物的生成和逸出。当温度高于550℃时,碳酸盐能催化Boudouard反应,氯化盐和硫酸盐均能促进该反应的进行。其中,Ni Cl2和Co Cl2对该反应的影响尤其明显。研究为生物质资源的高值化利用提供了一定的理论参考。     

Examination of ester sulfates in Podzolic and Regosolic soils using an immobilized arylsulfatase reactor

The enzyme kinetics of an immobilized arylsulfatase reactor were examined. We found that the optimum operating conditions for the reactor were pH 7.0 and 25°C, using p-nitrophenyl sulfate in acetate buffer. The Michaelis constant (K _m) of immobilized arylsulfatase was 5.29 mM, compared with a K _m of 2.18 mM for soluble arylsulfatase from the same source (Helix pomatia). Since arylsulfatase hydrolyzes organic ester sulfate linkages, the immobilized arylsulfatase reactor was used to examine ester sulfate compounds in two soils subjected to different fertility management schemes. Soil samples were obtained from the Ap horizons of a Podzol from S-amended wheat plots and a Regosol from dykeland hayfield plots which had received additions of NH₄NO₃ and compost. The distribution of S in these soils was examined in the fall of 1993 and the spring of 1994. Soil organic matter was extracted and separated into three molecular weight fractions (<500, 500–10 000, >10 000). There was no difference in the ester sulfate content for the >10 000 fraction of control and S-amended Podzol soils; however, the S-amended samples had significantly higher quantities of hydrolysable ester sulfates than controls for the 500–10 000 range, indicating that S amendments resulted in the incorporation of ester sulfate into this lower molecular weight fraction. Both control and NH₄NO₃ treatments to the Regosol showed significantly higher quantities of hydrolysable ester sulfates in the >10 000 fraction, while compostamended plots showed no difference between the >10 000 and 500–10 000 fractions due to suspected microbial degradation of high molecular weight organic S compounds in the compost. Since there was no significant effect of sampling time, this study indicated that naturally occurring low molecular weight ester sulfate compounds accumulate in soil and persist during storage. Hydrolysable ester sulfates constituted 35–55% of the hydriodic acid-reducible S in these different soils and probably represent an important and easily mineralizable portion of total ester sulfates.     

Characterization of the exopolysaccharide produced by Salipiger mucosus A3, a halophilic species belonging to the Alphaproteobacteria, isolated on the Spanish Mediterranean seaboard

We have studied the exopolysaccharide produced by the type strain of Salipiger mucosus, a species of halophilic, EPS-producing (exopolysaccharide-producing) bacterium belonging to the Alphaproteobacteria. The strain, isolated on the Mediterranean seaboard, produced a polysaccharide, mainly during its exponential growth phase but also to a lesser extent during the stationary phase. Culture parameters influenced bacterial growth and EPS production. Yield was always directly related to the quantity of biomass in the culture. The polymer is a heteropolysaccharide with a molecular mass of 250 kDa and its components are glucose (19.7%, w/w), mannose (34%, w/w), galactose (32.9%, w/w) and fucose (13.4%, w/w). Fucose and fucose-rich oligosaccharides have applications in the fields of medicine and cosmetics. The chemical or enzymatic hydrolysis of fucose-rich polysaccharides offers a new efficient way to process fucose. The exopolysaccharide in question produces a solution of very low viscosity that shows pseudoplastic behavior and emulsifying activity on several hydrophobic substrates. It also has a high capacity for binding cations and incorporating considerable quantities of sulfates, this latter feature being very unusual in bacterial polysaccharides.     

Enzyme-Assisted Extraction of Bioactive Material from Chondrus crispus and Codium fragile and Its Effect on Herpes simplex Virus (HSV-1)

Codium fragile and Chondrus crispus are, respectively, green and red seaweeds which are abundant along the North Atlantic coasts. We investigated the chemical composition and antiviral activity of enzymatic extracts of C. fragile (CF) and C. crispus (CC). On a dry weight basis, CF consisted of 11% protein, 31% neutral sugars, 0.8% sulfate, 0.6% uronic acids, and 49% ash, while CC contained 27% protein, 28% neutral sugars, 17% sulfate, 1.8% uronic acids, and 25% ash. Enzyme-assisted hydrolysis improved the extraction efficiency of bioactive materials. Commercial proteases and carbohydrases significantly improved (p ≤ 0.001) biomass yield (40%–70% dry matter) as compared to aqueous extraction (20%–25% dry matter). Moreover, enzymatic hydrolysis enhanced the recovery of protein, neutral sugars, uronic acids, and sulfates. The enzymatic hydrolysates exhibited significant activity against Herpes simplex virus (HSV-1) with EC₅₀ of 77.6–126.8 μg/mL for CC and 36.5–41.3 μg/mL for CF, at a multiplicity of infection (MOI) of 0.001 ID₅₀/cells without cytotoxity (1–200 μg/mL). The extracts obtained from proteases (P1) and carbohydrases (C3) were also effective at higher virus MOI of 0.01 ID₅₀/cells without cytotoxity. Taken together, these results indicate the potential application of enzymatic hydrolysates of C. fragile and C. crispus in functional food and antiviral drug discovery.     

甘肃阿克塞海子地区羊食毛症治疗试验

在阿克塞县羊食毛症流行病区,选择60例患严重食毛癖羊只(山羊45,绵羊15),随机分为对照组和试验组(每组30只)。然后将试验组又随机分为试验Ⅰ组、Ⅱ组和Ⅲ组,分别补饲以硫酸亚铁、硫酸亚铁+硫酸铜、硫酸铝。对照组不作任何治疗处理。临床观察和实验室元素分析结果表明:3个不同试验组近期疗效都达到了100％,其中以硫酸铝组疗效较迅速且稳定;对照组无一例自愈。