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本研究在以前研究的基础上进行中间试验,利用以下工艺流程从杜仲叶中制得绿原酸纯品:40%乙醇提取(80℃,2h,1∶16料液比,提取2次)→制备浸膏(真空浓缩,80℃鼓风干燥)→加水转溶(4次)→铅盐沉淀(每100g杜仲叶用140g乙酸铅)→解析绿原酸(20%H2SO4)→乙酸乙酯萃取(约20次)→浓缩析出粗品→重结晶得纯品,平均得率0.53%,纯度98.35%。
研究中还发现杜仲叶中不含异绿原酸。
杜仲(EucommiaulmoidesOliv.)为杜仲科(Eucommiaceae)杜仲属植物,富含绿原酸。
作者曾对影响杜仲叶中绿原酸提取率的各种因素进行了研究,得出了提取绿原酸的最佳工艺条件[1]。
本研究在此基础上,利用所得出的最佳工艺条件进行放大提取试验,用铅沉法对提取出的绿原酸进行分离,得到（通常用的最多的是第二种，即分配平衡，）色谱分离原理高效液相色谱法按分离机制的不同分为液固吸附色谱法、液液分配色谱法（正相与反相）、离子交换色谱法、离子对色谱法及分子排阻色谱法。
1．液固色谱法使用固体吸附剂，被分离组分在色谱柱上分离原理是根据固定相对组分吸附力大小不同而分离。
分离过程是一个吸附－解吸附的平衡过程。
常用的吸附剂为硅胶或氧化铝，粒度5~10μm。
适用于分离分子量200~1000的组分，大多数用于非离子型化合物，离子型化合物易产生拖尾。
常用于分离同分异构体。
2．液液色谱法使用将特定的液态物质涂于担体表面，或化学键合于担体表面而形成的固定相，分离原理是根据被分离的组分在流动相和固定相中溶解度不同而分离。
分离过程是一个分配平衡过程。
涂布式固定相应具有良好的惰性；流动相必须预先用固定相饱和，以减少固定相从担体表面流失；温度的变化和不同批号流动相的区别常引起柱子的变化；另外在流动相中存在的固定相也使样品的分离和收集复杂化。
由于涂布式固定相很难避免固定液流失，现在已很少采用。
现在多采用的是化学键合固定相，如C18、C8、氨基柱、氰基柱和苯基柱。
２００６年第４ｌ卷第３期生物学通报１９植物次生物的代谢途径季志平苏印泉张存莉（西北农林科技大学林学院陕西杨陵７１２１００）摘要系统地介绍了关于植物次生物代谢途径方面的研究成果．归纳了植物次生物的３个主要代射途径：酚类代谢途径、萜类代谢途径、生物碱代谢途径，并对其代谢机理进行了探讨。
关键词次生代谢物代谢途径机理植物次生代谢产物是植物体利用某些初生代谢产物，在一系列酶的催化作用下，形成的一些特殊化学物质。
这些化学物质是细胞生命活动或植物正常生长发育非必需的小分子有机化合物．其产生和分布通常有种属、器官、组织以及生长发育时期的特异性。
次生代谢产物是植物对环境适应的结果。
次生代谢物为人类提供了丰富的药物、香料和工业原料．对人类的生产和生活具有重要的作用。
植物次生代谢物种类繁多，结构迥异，一般分为酚类、萜类、含氮有机物三大类，每一类已知化合物都有数千种甚至数万种以上，如黄酮类、酚类、香豆素、木脂素、生物碱、萜类、甾类、皂苷和多炔类等。
这些次生代谢产物在植物体内主要通过苯丙烷代谢途径、异戊二烯代谢途径、生物碱合成途径形成。
莽草酸途径主要能提供合成一些次生代谢物的前体。
１酚类合成途径酚类主要包括黄酮类、简单酚类和醌类等。
黄酮类化合物系色原烷（ｃｈｒｏｍａｎｅ）或色原酮（ｃｈｍｍａｎｅ）的２一或３一苯基衍生物，泛指由两个芳香环（Ａ和Ｂ）通过中央三碳链相互连接而成一系列化合物．可以分为１４种主要类型．酚类化合物主要是通过苯丙基类生物合成途径合成的（图１）。
植物次生代谢物的合成途径通常是以不同类别的次生代谢物合成途径为单位即代谢频道（ｍｅｔａｂｏｌｉｃｃｈａｎｎｅｌ）的形成存在。
不同代谢频道分布在植物不同的器官、组织、细胞或细胞内不同的细胞器即分隔（ｃｏｍ．ｐａｒｔｒｎｅｎｔ）内，不同代谢频道ＱＴＬ（ｑｕａｎｔｉｔａｔｉｖｅｔｒａｉｔｌｏｃｉ）可能分布在不同的染色体上．次生代谢物生物合成“代谢频道”的存在，有效地隔绝了次生代谢物合成过程中间产物在细胞内扩散，有利于底物与酶的有效结合和酶促反应的顺利进行，减少次生代谢途径中不同支路之间争夺底物的现象及有毒中间产物对细胞的伤害，并使细胞内多种类型次生代谢物的合成途径得以同时存在。
羟羟基肉桂酸衍生物
羟基肉桂酸衍生物指的是以羟基肉桂酸为基础衍生出来的化合物。
羟基肉桂酸，又称3-羟基-3-苯基丙酸，是一种有机化合物，化学式为C9H9O3。
羟基肉桂酸衍生物的例子包括但不限于：
1.3-硝基-4-羟基肉桂酸，是香豆素类化合物的母核，可用于制备抗疟疾药物
和开发抗病毒剂等。
2.香豆素，可广泛用于天然或合成的香料，在农药、医药和染料工业中也有
应用。
3.3-甲氧基-4-羟基肉桂酸，是一种具有抗炎、抗肿瘤、抗突变、抗心律失常
等生物活性的化合物。
总结来说，羟基肉桂酸衍生物是一类以羟基肉桂酸为基础通过化学反应得到的化合物，它们在医药、农药、染料等领域有广泛的应用。
对羟基苯氧基丙酸对羟基苯氧基丙酸（4-hydroxyphenoxylpropionic acid）是一种化合物，化学式为C9H10O4。
它是一种有机酸，由一个苯环上的羟基和一条长为3个碳原子的侧链上的羟基和羧基组成。
它可作为合成聚合物等有机化合物的原料，也可用于制备有机溶剂和功能性材料。
对羟基苯氧基丙酸是一种具有烷基羟酸结构的化合物。
它也被称为对羟基苯丙酸，其化学名称为2-(4-hydroxyphenoxy)propionic acid。
其分子结构中包含一个苯环上的羟基和一个丙烷侧链上的羟基和羧基。
对羟基苯氧基丙酸主要用于合成和制备各种有机化合物。
它可以作为合成聚合物的单体，用于合成具有特定功能的聚合物。
此外，对羟基苯氧基丙酸还可以用作表面活性剂、涂料和油墨的添加剂，它具有增润性和界面活性。
对羟基苯氧基丙酸也可以作为一种生物活性物质。
研究表明，它具有一定的抗氧化和抗菌性质，可以用于抗菌涂层和抗氧化保健品的制备。
此外，它还被开发用于农药和医药领域。
对羟基苯氧基丙酸也被广泛应用于农业领域。
它可以作为一种有效的除草剂，在农田中控制杂草的生长。
此外，对羟基苯氧基丙酸还可以用作一种植物生长调节剂，促进作物的生长和发育。
它具有增加作物产量、提高抗逆性和改善品质的作用。
此外，对羟基苯氧基丙酸还具有一定的医药应用价值。
研究发现，它具有抗炎、抗肿瘤和抗菌等活性。
因此，它被认为是一种潜在的抗癌和抗感染治疗的药物候选物质。
总之，对羟基苯氧基丙酸是一种具有多种应用领域的化合物。
它在合成聚合物、表面活性剂、涂料和油墨、除草剂、植物生长调节剂以及医药等领域都有广泛的应用前景。
木槿酸结构式全文共四篇示例，供读者参考第一篇示例：木槿酸，化学名称为3,4,5-三羟基苯丙酸，是一种天然存在于木槿科植物中的多酚类化合物。
木槿酸具有多种生物活性，被广泛应用于食品、药品和化妆品等领域。
以下将介绍木槿酸的结构式、性质、用途以及相关研究进展。
木槿酸的化学结构式为C9H10O5，分子量为198.17g/mol。
它是一种白色结晶固体，微溶于水，溶于乙醇和乙醚。
木槿酸的化学结构中包含三个羟基(-OH)官能团和一个苯环，这使其具有很强的生物活性和抗氧化性。
研究表明，木槿酸具有抗炎、抗氧化、抗菌和免疫调节等多种药理作用。
近年来，木槿酸的研究受到了广泛关注。
科学家们通过不断的实验和分析，发现了木槿酸在抗肿瘤、抗糖尿病和抗衰老等方面的潜在应用价值。
有研究表明，木槿酸可以抑制肿瘤细胞的生长和扩散，对多种肿瘤具有抗癌活性。
木槿酸还能够降低血糖和胰岛素抵抗，具有预防和治疗糖尿病的作用。
木槿酸还可以延缓皮肤衰老，减少皱纹和色斑的产生，保持肌肤年轻和健康。
木槿酸是一种具有广泛生物活性的天然化合物，具有很大的应用潜力。
未来，随着对木槿酸研究的不断深入，相信会有更多的发现和应用价值被挖掘出来，为人类的健康和生活带来更多的惊喜和希望。
希望木槿酸在未来的研究中能够发挥更大的作用，为人类健康和幸福贡献力量。
第二篇示例：木槿酸（Hibiscus acid），也称为肉豆蔻酸，是一种天然存在于多种植物中的有机酸。
它的结构式为C10H16O3，是一种脂溶性的化合物。
木槿酸可溶于醇类溶剂和酮类溶剂，微溶于水。
它具有抗氧化、抗菌和抗炎症等多种生物活性，因此在医药、保健品和化妆品等领域有着广泛的应用。
木槿酸的分子结构中含有一个环戊二烯骨架和一个环戊醇基，这使得它具有一定的抗氧化性能。
抗氧化性能是木槿酸被广泛研究的主要原因之一，它可以清除自由基，保护细胞免受氧化损伤，延缓衰老和预防疾病。
研究表明，木槿酸能够抑制过氧化物生成，降低脂质过氧化物的水平，保护细胞膜的完整性。
三甲氧基黄酮化学式
（最新版）
目录
1.三甲氧基黄酮的概述
2.三甲氧基黄酮的化学式
3.三甲氧基黄酮的应用领域
4.三甲氧基黄酮的结构特点
正文
三甲氧基黄酮是一种天然产物，属于黄酮类化合物，广泛存在于植物中，具有多种生物学活性。
例如，具有抗炎、抗氧化、抗肿瘤等药理作用。
三甲氧基黄酮的化学式为 C16H12O7，是一种黄色结晶性粉末。
其结构中含有一个三甲氧基取代基，使其具有特殊的稳定性和生物活性。
三甲氧基黄酮广泛应用于医药、食品添加剂、化妆品等领域。
在医药领域，三甲氧基黄酮可用于治疗心血管疾病、肿瘤等疾病。
在食品添加剂领域，三甲氧基黄酮可用作天然色素，增加食品的色泽。
在化妆品领域，三甲氧基黄酮具有良好的抗氧化性，可用作抗氧化剂，保护皮肤免受自由基的损伤。
三甲氧基黄酮的结构特点是其分子中含有一个三甲氧基取代基，这使得其具有特殊的稳定性和生物活性。
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生物技术进展 2023 年 第 13 卷 第 4 期 596 ~ 603Current Biotechnology ISSN 2095‑2341研究论文Articles重组贻贝粘蛋白的表征及功效评价李敏 ， 魏文培 ， 乔莎 ， 郝东 ， 周浩 ， 赵硕文 ， 张立峰 ， 侯增淼 *西安德诺海思医疗科技有限公司，西安 710000摘要：为了推进重组贻贝粘蛋白在医疗、化妆品领域的应用，对大肠杆菌规模化发酵及纯化生产获得的重组贻贝粘蛋白进行了表征及功效评价。
经Edman 降解法、基质辅助激光解吸电离飞行时间质谱、PITC 法、非还原型SDS -聚丙烯酰胺凝胶电泳法、凝胶法、改良的Arnow 法对重组贻贝粘蛋白进行氨基酸N 端测序、相对分子量分析、氨基酸组成分析、蛋白纯度分析、内毒素含量测定、多巴含量测定；通过细胞迁移、斑马鱼尾鳍修复效果对重组贻贝粘蛋白进行功效评价。
结果显示，获得的重组贻贝粘蛋白与理论的一级结构一致，蛋白纯度达95%以上，内毒素<10 EU ·mg -1,多巴含量大于5%；重组贻贝粘蛋白浓度为60 μg ·mL -1时能够显著促进细胞增殖的活性（P <0.01）；斑马鱼尾鳍面积样品组与模型对照组相比极显著增加（P <0.001）。
研究结果表明，重组贻贝粘蛋白具有显著的促细胞迁移和修复愈合的功效，具备作为生物医学材料的潜质。
关键词：贻贝粘蛋白；基因重组；生物材料；表征；功效评价DOI ：10.19586/j.20952341.2023.0021 中图分类号：S985.3+1 文献标志码：ACharacterization and Efficacy Evaluation of Recombinant Mussel Adhesive ProteinLI Min ， WEI Wenpei ， QIAO Sha ， HAO Dong ， ZHOU Hao ， ZHAO Shuowen ， ZHANG Lifeng ，HOU Zengmiao *Xi'an DeNovo Hith Medical Technology Co.， Ltd ， Xi'an 710000， ChinaAbstract ：In order to promote the application of recombinant mussel adhesive protein in the medical and cosmetics field ， the recombi⁃nant mussel adhesive protein obtained from scale fermentation and purification of Escherichia coli was characterized and its efficacy was evaluated. Amino acid N -terminal sequencing ， relative molecular weight analysis ， amino acid composition analysis ， protein purityanalysis ， endotoxin content ， dihydroxyphenylalanine （DOPA ） content of recombinant mussel adhesive protein were determined by the following methods ： Edman degradation ， matrix -assisted laser desorption ionization time -of -flight mass spectrometry （MALDI -TOF -MS ）， phenyl -isothiocyanate （PITC ）， nonreductive SDS -polyacrylamide gel electrophoresis （SDS -PAGE ）， gel method ， modified Ar⁃now. The efficacy of recombinant mussel adhesive protein was evaluated by cell migration and repairing effect of zebrafish tail fin. Re⁃sults showed that the obtained recombinant mussel adhesive protein was confirmed to be consistent with the theoretical primary structure ， protein purity of more than 95%， endotoxin <10 EU ·mg -1， DOPA content above 5%. When the recombinant mussel adhesive protein concentration was 60 μg ·mL -1， the effect of promoting cell proliferation was the most obvious ， and it had very significant activity （P <0.01）. The caudal fin area of zebrafish in sample group was significantly increased compared with model control group （P <0.001）. The results indicated that recombinant mussel adhesive protein can promote cell migration and repair healing and has the potential to be used as biomedical materials.Key words ：mussel adhesive protein ； gene recombination ； biological materials ； representation ； efficacy evaluation贻贝粘蛋白（mussel adhesive protein ， MAP ）也称作贻贝足丝蛋白（mussel foot protein ，Mfps ），收稿日期：2023⁃02⁃24； 接受日期：2023⁃03⁃31联系方式：李敏 E -mail:*******************;*通信作者 侯增淼 E -mail:***********************.cn李敏，等：重组贻贝粘蛋白的表征及功效评价是海洋贝类——紫贻贝（Mytilus galloprovincalis）、厚壳贻贝（Mytilus coruscus）、翡翠贻贝（Perna viri⁃dis）等分泌的一种特殊的蛋白质，贻贝中含有多种贻贝粘蛋白，包括贻贝粘蛋白（Mfp 1～6）、前胶原蛋白（precollagens）和基质蛋白（matrix proteins）等［1］。
p-Hydroxyphenyl,Guaiacyl,and Syringyl Lignins Have Similar Inhibitory Effects on Wall DegradabilityJohn H.Grabber,*John Ralph,Ronald D.Hatfield,and Ste´phane Quideau†U.S.Dairy Forage Research Center,Agricultural Research Service,U.S.Department of Agriculture,Madison,Wisconsin53706Studies with normal,mutant,and transgenic plants have not clearly established whether the proportion of p-hydroxyphenyl(H),guaiacyl(G),and syringyl(S)units in lignin directly affects the degradability of cell walls by hydrolytic enzymes.Dehydrogenation polymer-cell wall complexes containing varying ratios of H,G,and S lignins were formed by peroxidase/H2O2-mediated polymerization of p-coumaryl,coniferyl,and sinapyl alcohols into nonlignified walls isolated from cell suspensions of maize(Zea mays L).Lignification substantially reduced the degradability of cell walls by fungal hydrolases,but degradability was not affected by lignin composition.On the basis of these results,we propose that improvements in wall degradability,previously attributed to changes in lignin composition,were in fact due to other associated changes in wall chemistry or ultrastructure.Keywords:Gramineae;Zea mays;cell wall;brown midrib;transgenic;O-methyltransferase;hydroxycinnamyl alcohols;lignin;cellulase;degradabilityINTRODUCTIONLignins in angiosperms are formed by peroxidase/H2O2-mediated polymerization of p-coumaryl,coniferyl,and sinapyl alcohols(Figure1).At early stages oflignification,coniferyl alcohol and small amounts ofp-coumaryl alcohol are copolymerized into the primarywall to form mixed G and H ter,duringsecondary wall development,coniferyl alcohol and vari-able amounts of sinapyl alcohol are copolymerized toform mixed G and S lignins(He and Terashima,1990,1991).In some cases,however,secondary walls maybe lignified before primary walls(Vallet et al.,1996).The S/G ratio of lignin,as estimated by degradativetechniques,is not consistently correlated with cell wall degradability across or within normal genotypes(Bux-ton and Russell,1988;Jung and Casler,1991;Jung and Vogel,1992).Even in mutant and transgenic plants, wall degradability is not consistently associated with changes in the S and G content of lignin(Chabbert et al.,1994;Akin et al.,1986;Thorstensson et al.,1992; Lechtenberg et al.,1972;Bernard Vailhe et al.,1996a; Sewalt et al.,1997).Modifications in lignin composition are generally accompanied by changes in the concentra-tions of p-coumarate esters,ferulate cross-links,lignin, and other wall components(Chabbert et al.,1994;Lam et al.,1996;Thorstensson et al.,1992).The distribution of phenolics in walls,wall thickness,and plant anatomy may also be affected(Morrison et al.,1993;Grenet and Barry,1991;Goto et al.,1993;Bernard Vailhe et al., 1996b).Due to these and possibly other confounding effects,it has not been demonstrated whether lignin composition per se affects the enzymatic degradability of cell walls.Such information would provide a rational basis for directing plant selection or molecular engineer-ing efforts aimed at improving the bioconversion of structural polysaccharides into metabolizable energy for livestock or into ethanol fuels.In this study,dehydro-genation polymer-cell wall(DHP-CW)complexes were used to model how alterations in lignin composition affect wall degradability.MATERIALS AND METHODSDHP-CW complexes were formed by adding dilute H2O2 and varying proportions of p-coumaryl,coniferyl,and sinapyl alcohols to nonlignified walls isolated from cell suspensions of maize(Grabber et al.,1996).Monolignols were prepared according to the methods of Quideau and Ralph(1992).After complex formation,cell walls were thoroughly washed with water followed by acetone to remove unreacted monolignols and nonbound plexes were analyzed for Klason lignin without correction for acid-soluble lignin(Hatfield et al.,1994).Nonlignified walls and selected complexes were analyzed for lignin composition by pyrolysis GC-MS(Ralph and Hatfield,1991)and for alkali-labile ferulates and lignin following saponification at room temperature for20h with2 M aqueous NaOH.Ferulates were analyzed by GC-FID (Ralph et al.,1994).The quantity of lignin in alkaline extracts was estimated by comparing the absorbance(280nm)of diluted and acidified(pH2)extracts to that of G and mixed S-G DHPs(Grabber et al.,1996).Cell walls(100mg in10 mL of20mM acetate buffer,pH4.8,39°C)were degraded with hydrolases from Trichoderma reesei(4µL of Celluclast, NOVO)and Aspergillus niger(4µL of Viscozyme L,NOVO). The quantity of carbohydrate released from complexes by*Author to whom correspondence should be ad-dressed(e-mail jgrabber@).†Present address:Department of Chemistry and Biochemistry,Texas Tech University,Lubbock,TX 79409.Figure 1.Monolignol precursors of normal angiosperm lignins:p-coumaryl alcohol(R)R′)H);coniferyl alcohol (R)H,R′)OCH3);and sinapyl alcohol(R)R′)OCH3).2530J.Agric.Food Chem.1997,45,2530−2532S0021-8561(97)00029-0This article not subject to U.S.Copyright.Published1997by the American Chemical Societyhydrolases was estimated by a colorimetric technique (Dubois et al.,1956).RESULTS AND DISCUSSIONCell walls from maize cell suspensions are composed of about 0.3%G lignin,1.8%alkali-labile ferulates,10%protein,10%pectin,50%hemicellulose (primarily glu-curonoarabinoxylans with small amounts of mixed-linked glucans),and 25%cellulose (Grabber et al.,1995,1996).Overall,the composition of these cell walls are typical of nonlignified primary walls in grasses.Wall-bound peroxidases and exogenously supplied hydrogen peroxide were used to polymerize monolignols into cell walls to form DHP -CW complexes;Klason lignin concentrations ranged from 50to 220mg g -1.Previous work has demonstrated that lignins formed within these complexes are structurally similar to natural grass lignins (Grabber et al.,1996).Coniferyl alcohol and mixtures of coniferyl alcohol and p -coumaryl alcohol were consistently and efficiently polymerized into wall-bound DHPs (Figure 2).In many cases,Klason lignin concentrations were greater than pre-dicted,probably due to inclusion of some covalently bound ferulates,protein,or carbohydrate with lignin (Grabber et al.,1996).Lignification of walls with mixtures of sinapyl and coniferyl alcohols gave some-what more variable results.In cases where lignification efficiency was high,the relative abundance of pyrolysis products derived from S and G units was proportional to the ratio of sinapyl and coniferyl alcohol used to form complexes.Degradative analysis of S -G complexes by thioacidolysis also gave similar results (Grabber et al.,1996).These results indicate that the desired S -G lignins had been formed.Oxidation of sinapyl alcohol by maize peroxidases (for both cell suspensions and plants)is much less efficient than that of coniferyl alcohol (Hatfield,1996,unpublished results).This probably accounts for the variable polymerization of sinapyl alcohol into complexes.We are currently con-ducting experiments to determine if ferulate polysac-charide esters and p -coumaroylated lignin precursors enhance the formation of S lignins in maize.Ferulate or p -coumarate esters may enhance the formation of S lignins by peroxidases having a low affinity for sinapyl alcohol (Takahama et al.,1996).The quantity of ferulates released by saponification was reduced 90-95%when walls were lignified to a Klason lignin content of ca .120mg g -1with all monolignol mixtures.Ferulate polysaccharide esters are oxidatively coupled to lignin by alkali-stable bonds(Grabber et al.,1995).Therefore,the low recovery of alkali-labile ferulates indicates that all complexes had a similar,high degree of ferulate -lignin cross-linking.Lignin composition of complexes also did not affect the quantity of alkali-soluble lignin;about one-half of lignin (on a Klason lignin basis)was solubilized by 2M aqueous NaOH.These analyses,although limited in scope,suggest that lignin composition does not ap-preciably alter interactions between lignin and other matrix components.Nonlignified walls were rapidly and extensively de-graded by fungal enzymes with 395mg g -1of total sugars released after 6h and 735mg g -1of total sugars released after 72h of incubation.Due to variation in lignification efficiency (particularly for complexes formed with sinapyl alcohol),only replicates having high in-corporation rates of monolignols into wall-bound DHPs were used for degradability studies.Cell-wall degrad-ability was reduced to a similar degree by several monolignol mixtures (Table 1).Varying the proportionsFigure 2.Stoichiometry of DHP -CW complex formation with coniferyl alcohol (A),an equimolar mixture of coniferyl and p -coumaryl alcohols (B),and an equimolar mixture of coniferyl and sinapyl alcohols (C).Table 1.Lignin Concentration and Fungal Hydrolase Degradability of DHP -CW Complexes Formed with Coniferyl,p -Coumaryl,and Sinapyl Alcohols (n )3)acarbohydrate released monolignolKlason lignin 6h 72h coniferyl alcohol111221530coniferyl +p -coumaryl alcohol (1:1ratio)111212509coniferyl +sinapyl alcohol (1:1ratio)102221528CV%5.25.77.1aMeans within each column were similar (P >0.05).Concen-trations and degradability are given in units of mg per g of DHP -CW complex.Table 2.Lignin Concentration and Fungal Hydrolase Degradability of DHP -CW Complexes Formed withConiferyl Alcohol (CA)and Sinapyl Alcohol (SA,n )2)acarbohydrate released b ratio of CA:SA Klason lignin 6h 72h 100:08023062380:207422463860:408022462740:6085230627CV%10.80.81.6aMeans within each column were similar (P >0.05).Concen-trations and degradability are given in units of mg per g of DHP -CW complex.b Klason lignin concentration was used as a covariate to adjust means and to increase precision.Lignin Composition and Cell Wall Degradability J.Agric.Food Chem.,Vol.45,No.7,19972531of coniferyl and sinapyl alcohol used to form complexes also did not affect degradability(Table2).In addition, studies with DHP-CW complexes and Arabidopsis thaliana mutants indicate that lignin composition has no effect on the degradation of cell walls by mixed rumen microorganisms(Grabber et al.,1992;Jung and Chapple,1996).Overall,these results suggest that lignin composition does not directly affect the degrad-ability of cell walls by fungal enzymes or by rumen microorganisms.We propose that improvements in fiber degradability,previously attributed to modifica-tions in lignin composition of mutant and 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