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酶法提取黑加仑果渣花色苷的研究 总被引：2，自引：0，他引：2
通过单因素和正交试验,确定了黑加仑果渣花色苷酶法提取的最佳工艺条件为:釆用纤维素酶酶解,温度50℃,时间100min,果渣与酶解液的比1:9(g:mL),酶用量为原料质量的1%,pH值5.0,黑加仑花色苷提取率86.63%.釆用果胶酶酶解,温度50℃,时间120min,果渣与酶解液的比为1:8(g:mL),酶用量为原料质量的1.4%,pH值3.5,黑加仑花色苷提取率91.09%.并确定了使用果胶酶的提取效果好于纤维素酶. 相似文献
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研究了酶法提取荆芥总黄酮的工艺。通过单因素实验,探讨了粉碎度、料液比、酶解温度、酶解pH值、酶解时间、酶的用量对总黄酮提取率的影响,筛选出影响提取的主要因素,再通过正交实验,优化得到酶法提取荆芥总黄酮的最佳工艺条件。实验结果表明,各因素对提取率的影响顺序依次为粉碎度〉酶解时间〉酶的用量〉料液比。通过正交实验优选得到的最佳提取工艺为：药材粉碎度为50目,料液比为1：16,酶的用量为0．8％,酶解温度为40℃,酶解pH值为5,酶解时间为20min后,煎煮1．5h。该法操作简单、提取率高,可用于荆芥总黄酮的提取。 相似文献
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酶法提取侧柏叶总黄酮的研究 总被引：1，自引：0，他引：1
对酶法提取侧柏叶总黄酮类的工艺条件进行研究。以总黄酮得率为考察指标,探讨了影响提取的主要因素,并用正交实验确定了最佳提取工艺。结果表明,各因素对提取效果影响的顺序依次为酶解时间〉酶用量〉酶解温度〉酶解pH值,最佳工艺条件为：料液比1∶14,酶解温度45℃,介质pH3.5,酶用量0.3%,酶解时间2.0h,总黄酮得率可达1.026%。该提取工艺简便易行,重复性好。 相似文献
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响应面法优化纤维素酶辅助提取大果沙棘果渣总黄酮工艺研究 总被引：6，自引：0，他引：6
采用纤维素酶辅助法对沙棘果加工废弃物沙棘果渣中的总黄酮物质进行提取。在单因素试验的基础上,采用响应面分析法对酶辅助法提取沙棘果渣黄酮类物质提取条件进行优化。建立并分析了酶用量、液固比、提取温度和pH值4因子与总黄酮得率关系的数学模型。沙棘果渣黄酮类物质提取的最佳工艺条件为:纤维素酶用量78.9 IU/g,液固比值25.9,温度59.1℃,pH值3.9。试验证明,在此条件下,总黄酮得率为(8.48±0.16)mg/g(n=3),与模型预测值8.57 mg/g基本一致。响应面模型回归方程与实际情况拟合良好,能较好地预测大果沙棘果渣中总黄酮的提取得率。 相似文献
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目的:研究山桃稠李果实花色苷的提取及抗氧化,以期为其进一步开发利用提供理论基础。方法:以牡丹江产山桃稠李果实为原料,采用超声波辅助提取法,以花色苷得率为指标,探讨乙醇浓度、时间、固液比等因素对得率的影响;体外抗氧化模型研究其抗氧化能力。结果:乙醇浓度60%~75%,固液比1∶15~1∶20,超声波时间35~40 min,超声功率在400 W左右,提取温度在30~40℃左右时,可以作为进一步优化的参数条件,其浓度在1 mg/mL时,超氧自由基清除率在27%左右,其花色苷平均得率为:0.8 mg/g以上。结论:超声波法能快速提取山桃稠李果实中的花色苷,其花色显示一定抗超氧化能力。 相似文献
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L. A. Donaldson 《Wood Science and Technology》1988,22(1):33-41
Summary The ultrastructure of holocellulose and alpha-cellulose from Pinus radiata D. Don was examined after treatment with cellulase for either 24 hours or 7 days. A procedure for localising the enzyme in situ using phosphotungstic acid is described. The pattern of degradation differed between the two substrates with alpha-cellulose being much more susceptible to hydrolysis than holocellulose. In both substrates the primary wall showed evidence of hydrolysis after 24 hours and was completely hydrolysed after 7 days. In holocellulose after 7 days treatment, hydrolysis of the secondary wall was confined to localised areas of the S3 layer sometimes penetrating into the S2 region. In contrast, alpha-cellulose showed uniform degradation across the secondary wall. Enzyme did not appear to penetrate the holocellulose but full penetration occurred in alpha-cellulose, the enzyme being closely associated with individual microfibrils. The reasons for these differences in degradation pattern are discussed. 相似文献
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Summary The degradation of microfibrils from Valonia ventricosa by cellulase has been studied. As a result of enzymatic attack the elementary fibrils making up the microfibrils tended to separate and the ends of the microfibrils became oblique or pointed. The terminal planes made angles of 60 ... 66°, 33°, or 20 ... 25° with the microfibril axis. These planes are assumed to correspond to the 41
, 43
and 45
planes of the cellulose lattice and it is suggested that they are planes along which it is progressively more difficult for hydrolysis to proceed. On the basis of these considerations a suggestion has been proposed to explain the form of erosion cavities formed by soft-rot fungi described by previous workers in wood fibres and tracheids.
Zusammenfassung Der Cellulase-Abbau von Mikrofibrillen aus Valonia ventricosa wurde untersucht. Die enzymatische Wirkung führt dazu, daß die Elementarfibrillen, welche die Mikrofibrillen bilden, eine Tendenz zur Ablösung zeigen und daß die Enden der Mikrofibrillen schräg oder spitz zulaufen. Die Endflächen bilden mit der Mikrofibrillenachse Winkel von 60 ... 66°, 33° oder 20 ... 25°. Es wird angenommen, daß diese Flächen mit den Ebenen 41 , 43 and 45 des Cellulosegitters übereinstimmen und daß entlang dieser Ebenen die Hydrolyse zunehmend schwieriger wird. Aufgrund dieser Überlegungen wird eine Hypothese entwickelt, welche zur Erklärung der von den Moderfäulepilzen erzeugten, erosiven Vertiefungen dient, die bereits in verschiedenen Arbeiten über Holzfasern und Tracheiden beschrieben wurden.相似文献
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Four lignans — pinoresinol, lariciresinol, secoisolariciresinol, matairesinol — were isolated from each ofDaphne odora andDaphne genkwa (Thymelaeaceae). Matairesinol isolated from both plants was optically pure (>99% e.e.) and dextrorotatory. Pinoresinol and lariciresinol isolated from the plants were not optically pure, and their enantiomeric compositions ranged from 88% to 95% e.e. in favor of (–)-enantiomers. As for secoisolariciresinol, the one fromD. odora was optically pure [(+)-enantiomer, >99% e.e.], and that fromD. genkwa was 97% e.e. in favor of the (+)-enantiomer. Lignan-synthesizing enzyme activity was detected from a Thymelaeaceae plant for the first time; cell-free extracts fromD. genkwa catalyzed the formation of (–)-lariciresinol (23% e.e.) from racemic (±)-pinoresinols. The stereochemistry of the enzymatic reaction is discussed in relation to the stereochemical features of the isolated lignans.Parts of this report were presented at the 42nd Lignin Symposium, Sapporo, October 1997; 48th Annual Meeting of the Japan Wood Research Society, Shizuoka, April 1998; and 49th Annual Meeting of the Japan Wood Research Society, Tokyo, April 1999 相似文献
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Wang Kun Wang Fang Jiang Jian-xin Zhu Li-wei Fan Hong-zhuai 《中国林学(英文版)》2007,9(2):137-141
Pretreatment of lespedeza stalks by steam explosion has been studied. The results indicate that steam-exploded pretreatment has strong effects on physical features, morphology, crystallinity, and composition of lespedeza stalks as shown by scanning electron microscopy (SEM), infrared (IR), and X-ray diffraction spectrometry methods. After steam explosion, the cellulose and lignin contents of lespedeza stalks varied only slightly, but the hemicellulose content had decreased from 29.34% to 7.48%. The cellulose obtained by steam-exploded pretreatment had a higher degree of crystallinity than that of the raw material. At the explosion condition of 2.25 MPa and 4 min, lignocellulose is easier to hydrolyze by enzyme than the original lignocellulose. The concentration of reduced sugar in the hydrolyzate liquid increased from 71.77 to 162.84 g·L–1. 相似文献
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Shiro Suzuki Norikazu Sakakibara Toshiaki Umezawa Mikio Shimada 《Journal of Wood Science》2002,48(6):536-541
Gas chromatography — mass spectrometry analysis of the -glucosidase-treated MeOH extracts ofAnthriscus sylvestris showed, based on comparison of the mass spectra and retention times with those of authentic samples, the presence of lignans, yatein, secoisolariciresinol, lariciresinol, matairesinol, hinokinin, and pluviatolide. The existence of small amounts of bursehernin was suggested by mass chromatography. In addition, nemerosin and deoxypodophyllotoxin were tentatively identified by comparing the mass spectra with those reported in the literature. Enzyme preparations fromA. sylvestris catalyzed the formation of secoisolariciresinol and lariciresinol from coniferyl alcohol. Furthermore, the enzyme preparation catalyzed the formation of lariciresinol from (±)-pinoresinols and the formation of secoisolariciresinol from (±)-lariciresinols. Thus, pinoresinol/lariciresinol reductase (PLR) activity was detected. Chiral high-performance liquid chromatography analysis showed selective formation of (+)-lariciresinol and (–)-secoisolariciresinol from (±)pinoresinols with theA. sylvestris PLR preparation, indicating that the stereochemical property ofA. sylvestris PLR-catalyzed reduction was similar to those ofForsythia PLR andArctium lappa ripening seed PLR.Part of this report was presented at the 43rd Lignin Symposium, Fuchu, October 1998 相似文献
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Quan Xia Dujuan Xu Zhaogang Huang Jianjun Liu Xinqun Wang Xiu Wang Shangquan Liu 《Fitoterapia》2010,81(5):437-442
It has been reported that icariin and icariside II, two flavonoid glycosides coming from herba epimedii, which have a closely structural relationship, show some pharmacological effects such as preventing osteoporosis, cancer and depression. The content of natural icariside II is very low in herba epimedii, but it is the main component in vivo after the administration of herba epimedii. More icariside II can be obtained from icariin by enzymatic hydrolysis method than by traditional isolation method. This study focuses on finding a simple and feasible method to prepare icariside II from icariin by enzymatic hydrolysis, so as to meet the request for further pharmacologic actions study. Icariin was obtained successively with 90% ethanol extraction, isolation on macroporous resin and purification on silica gel chromatography. Enzymatic hydrolysis conditions were tested for the bioconversion of icariin into icariside II by orthogonal array design. The structures of isolated icariin and produced icariside II were identified by UV, IR, ESIMS, 1H NMR, 13C NMR, and DEPT spectroscope. Enzymatic hydrolysis experiment showed that icariin could be transformed into icariside II with the action of β-glucosidase and the optimum reaction conditions were determined as follows: 50 °C, 0.2 M disodium hydrogen phosphate and citric acid buffer system (pH6.0), the ratio of icariin/enzyme is 1:1 and reaction time 5 h. By using this enzymatic condition, 95.5 mg icariside II (with the purity of 99.1%) was obtained eventually by transforming 200 mg icariin. 相似文献
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Dr. G. Ucar 《Wood Science and Technology》1990,24(2):171-180
Summary The dilute acid pretreatment in a plug flow reactor and alkali pretreatments with caustic solutions at different conditions followed by enzymatic hydrolysis resulted in drastically improved glucose yields for aspen and hybrid poplar. The acid pretreatment conditions must be carefully chosen to open the cellulosic structure allowing rapid diffusion of enzyme. The effectiveness of pretreatment is chiefly based on the enlargement of the pore size suitable for enzyme molecules.This work was carried out at Thayer School of Engineering, Dartmouth College in New Hampshire. The author wishes to express his gratitude to Prof. H. E. Grethlein for all kind support and helpful discussions 相似文献
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This study focused on poplar (Populus tomentosa) catkin fiber as a new resource for bioethanol production via enzymatic hydrolysis. The poplar catkin fiber was found to have advantages of relatively high α-cellulose content (44.5%), and low lignin content (2.9%), which indicated the potential for facile enzymatic hydrolysis. The results indicated that the pretreatment improved the cellulose-to-glucose conversion yield (CGCY), the high concentration alkaline pretreatment resulted in highest CGCY (83.3%), followed by dewaxing (31.5%), dilute alkaline (29.8%), and dilute acid pretreatment (24.4%) after enzymatic hydrolysis with cellulase of 15 filter paper units per gram glucan, while the poplar catkin fiber only achieved 18.7% of CGCY by enzymatic hydrolysis after 48 h at 50 °C without any pretreatment. 相似文献
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Dr. Eiichi Maekawa 《Wood Science and Technology》1996,30(2):133-139
Summary In order to aim at a proved pretreatment for the enzymatic saccharification of lignocellulosic materials, the combined effect of the steam explosion treatment and the newly added alkali-hydrogen peroxide treatment was investigated. As a result, the following findings were obtained from comparison of the saccharification ratio (%) among the materials used: 1) Marked differences based on the lignocellulosic species characteristic of biological materials were observed. 2) Lignocellulosic samples such as rice straw, poplar, and maple chips gave enzymatic saccharification ratio (%) close to 100% by using the samples obtained after extraction with various solvents without alkali-hydrogen peroxide treatment. 3) Chip samples such as Japanese larch, loblolly pine, and Japanese cypress gave the very low enzymatic saccharification ratio (%) of 20–40% after the steam explosion and extraction with various solvents. 4) In comparison with enzymatic saccharification ratio (%) of original samples treated with steam explosion, alkali-hydrogen peroxide treatment resulted in greater effect based on the treatment of 2–2.5 times. 5) Alkali-hydrogen peroxide treatment afforded remarkable effects based on the treatment of the softwoods, such as Japanese larch and loblolly pine.The author is indebted to Professor Mitsuhiko Tanahashi, Faculty of Agriculture, Gifu University, for assistance on preparation of various lignocellulosic samples using a steam explosion equipment. The investigation was supported by the grant-in-aid for scientific research of the Ministry of Education in Japan 相似文献
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Dr. H. Militz 《Wood Science and Technology》1993,28(1):9-22
Summary Finely ground spruce wood (Picea abies (L.) Karst.) was incubated with various commercial enzyme preparations; the incubation liquid was analysed for the presence and volume of uronic acids and neutral sugars. The tested enzyme preparations dissolved neutral and acid sugar from the woodpowder. The most effective enzyme preparations were cellulolytic enzymes with some hemicellulolytic activites. This applied to the decomposition of neutral polysaccharide as well as to polyuronide. The polysaccharides in the cell wall were almost completely broken down to low molecular weight sugars by these preparations. Pectinase preparations, on the other hand, had lower efficacy in decomposing neutral and acid polysaccharides. A difference in efficacy of the enzyme preparations in decomposing heart- or sapwood could not be ascertained. 相似文献