A quick,easy, cheap,effective, rugged,and safe sample pretreatment and liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of 33 mycotoxins in Lentinula edodes

Lentinula edodes, one of the most cultivated edible fungi in the world, are usually neglected for mycotoxins contamination due to the initial thinking of its resistance to mycotoxingenic molds. In the present study, a sensitive and reliable liquid chromatography with tandem mass spectrometry method was developed for the simultaneous quantification of 33 mycotoxins in L. edodes. Targeted mycotoxins were extracted using a quick, easy, cheap, effective, rugged, and safe procedure without any further clean‐up step, and analyzed by liquid chromatography with tandem mass spectrometry on an Agilent Poroshell 120 EC‐C₁₈ column (100 × 3 mm, 2.7 μm) with a linear gradient elution program using water containing 5 mM ammonium acetate and methanol as the mobile phase. After validation by determining linearity (R² > 0.99), sensitivity (LOQ ≤ 20 ng/kg), recovery (73.6–117.9%), and precision (0.8–19.5%), the established method has been successfully applied to reveal the contamination states of various mycotoxins in L. edodes. Among the 30 tested samples, 22 were contaminated by various mycotoxins with the concentration levels ranging from 3.3–28 850.7 μg/kg, predicting that the edible fungus could be infected by the mycotoxins‐producing fungi. To the best of our knowledge, this is the first report about real mycotoxins contamination in L. edodes.     

STRUCTURE, MOLECULAR WEIGHT AND BIOACTIVITIES OF (1→3)-β-D- GLUCANS AND ITS SULFATED DERIVATIVES FROM FOUR KINDS OF LENTINUS EDODES

Lentinan samples, (1→3)-β-D-glucans containing 4.6-15.2 wt% proteins, coded as L-I1, L-I2, L-I3 and L-I4 (L-I)were isolated from four kinds of Lentinus edodes. These glucans were treated with acetone to remove the protein in order to obtain free protein glucans coded as LNP-I1, LNP-I2, LNP-I3 and LNP-I4 (LNP-I). The free-protein polysaccharides were sulfated to give derivatives (S-LNP-I) with degree of substitution (DS) from 0.4-0.8. The structural features and weight- average molecular weight (Mw) of the samples were investigated by using infrared spectroscopy, elemental analysis,13C-NMR, size exclusion chromatography combined with laser light scattering (SEC-LLS) and viscometry. The effects of structure and conformation of the polysaccharides on antitumor activities were assayed in vivo (Sarcoma 180 solid tumors)and in vitro (Sarcoma 180, HL-60, MCF-7 and Vero tumors). The results indicated that the predominant species of the samples L-I and LNP-I in 0.2 mol/L NaCl aqueous solution existed as triple-helical chains with high rigidity and in dimethyl sulfoxide (DMSO) as single-flexible chains. Interestingly, the antitumor activities of LNP-I are lower than those of the native glucans (L-I), whereas their sulfated derivatives have higher inhibition ratio against Sarcoma 180 than LNP-I. The results reveal that the binding of protein, sulfated modification and the triple helix conformation are important factors in the enhancement of the antitumor activities of polysaccharides on the whole.     

He-Ne激光在香菇速生高产菌株选育中的应用 Ⅱ酯酶同工酶分析及中试栽培

采用He－Ne激光诱变选育的6株香菇菌种酯酶同工酶与亲本相比，酶带条纹数、迁移率等特征发生了明显的改变，表明了在激光作用下，香菇菌丝体遗传物质发生了变异．所选育的香菇新菌种中试栽培结果表明：新菌种在生产条件下，生长周期平均缩短20天以上，香菇产量最低平均提高10％以上，最高可提高22.5％．     

液相色谱-离子阱质谱法测定香菇中的核苷酸

采用液相色谱-电喷雾串联质谱法检测香菇中核苷酸。流动相为甲醇和0.1%甲酸溶液,采用梯度洗脱程序,色谱柱为Zorbax XDB-C18（150×2.0mmid,5μm）,流速为0.2mL·min-1。以准分子离子和二级碎片离子对样品中4种核苷酸进行定性和定量,方法的检测限分别为0.500、0.050、0.020、0.010μg/g,相关系数分别为0.9952、0.9967、0.9935、0.9987,相对标准偏差范围为3.25%—9.45%,样品的回收率为78.2%—115.3%。该法快速、灵敏度高、重现性好。     

He-Ne激光诱变的香菇变异株遗传稳定性分析

对三株香菇菌种采用He-Ne激光(λ=6328nm)进行两次照射,筛选出三株比出发菌株菌丝生长速率分别提高173%、737%和426%的变异株,经传代培养及酯酶同工酶谱分析,变异株具有良好的遗传稳定性表明激光作为微生物新型诱变因子与传统化因子相比,具有正变率高、回复突变率低、遗传稳定性好的特点.     

香菇多糖L-2A的结构表征

从香菇子实体中提取纯化得到香菇多糖级分L-2A,利用紫外光谱、红外光谱、凝胶渗透色谱和气相色谱分析其结构特征.香菇多糖L-2A糖含量为90.14%;重均分子量是2.03×10 5道尔顿;具有D-葡萄吡喃糖构型,单糖组成主要是由吡喃型葡萄糖组成;香菇多糖L-2A多糖含有o-糖苷键,且主要是o-Ser连接方式;具有与刚果红结合的螺旋结构.香菇多糖L-2A为首次从香菇子实体中分离得到.     

香云多糖的分子表征和稀溶液性质研究

香菇和云芝是一类高等腐生真菌,菌种系由树上采集的子实体分离得到,由菌种培养得到的香菇和云芝菌丝体可以用来提取香云多糖。据国内外文献报道,香云多糖不仅对多种疾病有较好的疗效,而且还具有强烈的抑瘤作用。近年来国内外学者对其化学特性进行了研究,发现由不同的培养方法和经不同的纯化处理可以得到不同的产物。Sasaki的研究指出,香云多糖的抗肿瘤活性是以分子量适当高的较之分子量低的活性要高。但     

Optimised isolation of polysaccharides from Lentinula edodes strain NCBI JX915793 using response surface methodology and their antibacterial activities

Mycelial growth in a defined medium by submerged fermentation is a rapid and alternative method for obtaining fungal biomass of consistent quality. Biomass, exopolysaccharides (EPS) and intracellular polysaccharides (IPS) production were optimised by response surface methodology in Lentinula edodes strain LeS (NCBI JX915793). The optimised conditions were pH 5.0, temperature 26°C, incubation period of 25 days and agitation rate of 52 r/min for L. edodes strain LeS. Under the calculated optimal culture conditions, biomass production (5.88 mg mL^? 1), EPS production (0.40 mg mL^? 1) and IPS production (12.45 mg g^? 1) were in agreement with the predicted values for biomass (5.93 mg mL^? 1), EPS (0.55 mg mL^? 1) and IPS production (12.64 mg g^? 1). Crude lentinan exhibited highest antibacterial effects followed by alcoholic, crude and aqueous extracts. The results obtained may be useful for highly effective yield of biomass and bioactive metabolites.     

浊点滴定法确定香云多糖溶液的θ组成

<正> 香云多糖是由香菇(Lentinus edodes)和云芝(Polystictus Vorsicolor)菌丝体中提取而得.近年研究表明,具有抑瘤作用.关于香云多糖的药理作用和元素分析已有不少报道,但对其结构及形态与药理间的作用关系了解甚少.本文以香云多糖稀溶液,采用Elias浊点滴定法,取微浊点为溶液的浊点,确定了香云多糖溶液的θ组成. 1.仪器及样品 香云多糖为南京大学生物系提取,丙酮、乙醇为AR级,蒸馏水重蒸.超级恒温水浴     

富硒香菇规模化栽培实验及其富硒规律研究

为了了解规模化栽培后富硒香菇的产量(生物学效率)及富硒规律,通过香菇栽培基质添加模式,采取规模化生产进行富硒香菇栽培实验,选取不同浓度硒营养强化剂对香菇品种“向阳二号”和“9608”进行添加,测定相对应的香菇生物学效率以及第一潮次和第二潮次的总硒及硒代氨基酸的含量。实验发现“向阳二号”香菇,在硒添加量较低(0～6 mg/kg)时,香菇的生物转化率基本不随硒添加量的增加而改变,当硒添加量继续增加(10～60 mg/kg)时,香菇的生物转化率整体低于低添加量;“9608”香菇,随着硒添加量的增加(0～60 mg/kg),香菇的生物转化率表现出微弱的增加趋势,但差异性不显著;而两种不同品种、潮次香菇的总硒及硒代氨基酸含量均随着硒添加量的增加而提高,但硒代氨基酸占总硒的比例变化趋势却有所不同,在66.7%～85.4%。此外,对于不同品种的香菇,其第一潮次总硒含量在硒的添加量0～20 mg/kg的范围内呈现良好的规律性,总硒是基质(风干)中硒含量的约4～5倍。可见,按照拟定的规模化栽培模式进行生产栽培,可以得到总硒含量稳定、硒代氨基酸占总硒比>65%的富硒香菇产品,对富硒香菇产业的发展有一...