色谱指纹图谱组合相似度的算法

色谱指纹图谱相似度是评价中药质量稳定性的有效手段之一,其中向量夹角余弦相似度应用最为广泛。但是当色谱峰面积分布范围宽时,夹角余弦对数据的差异响应不灵敏。以土茯苓色谱指纹图谱数据为实例证实了当两样本数据间比例相差较大时,夹角余弦相似度对共有峰和非共有峰响应的灵敏程度相差很大。组合相似度在共有峰的夹角余弦相似度基础上纳入了非共有峰的影响,分别计算非共有峰和共有峰对相似度的贡献,并以最大峰比例同态性为指标,确定非共有峰的合适权重。基于样本峰面积数据建立的组合相似度模型能灵敏地反映待测样本与参照样本内在成分的峰比例变化,适合衡量多个药材样本间的相似程度,已成为评价药材质量相似度的新方法。     

相似系统理论定量评价中药材色谱指纹图谱的相似度

研究相似系统理论定量评价中药材提取物液相色谱指纹图谱的相似度。以相似系统理论对栀子药材提取物高效液相色谱指纹图谱的相似度评价,发现相似系统理论对数据的差异比较敏感,而且相似度的计算结果能够反映样品的相对差异。相似系统理论可以作为一种评价中药色谱指纹图谱相似度的新方法。     

基于相似系统理论的相似度计算方法的改进

针对常用的相似度方法对色谱指纹图谱数据的相对差异响应不灵敏,本文对基于相似系统理论的改良程度相似度的计算方法进行了改进。模拟数据和乳块消片色谱指纹图谱数据计算结果表明,改进后的新改良程度相似度q′可区分与参照样本的总差异相同,但差异分布不同的样本。在共有峰峰面积差异不超过100%的情况下,新改良程度相似度q′计算方法能够更灵敏地反映两样本的峰面积的相对差异。本研究的新改良程度相似度q′能突出组分群中某些组分对既定配比的较大偏离,适用于中药成分群配比波动的控制和中药过程质量控制。     

利用样本成分耗散物的非线性化学指纹图谱原理及相似度计算与评价

在恒温恒压条件下,以丙酮和样本中底物作为主要耗散物的不同成分的样本对非线性化学反应机理产生不同影响,从而引起反应体系电位-时间曲线形状不同变化为特征的B-Z化学振荡体系为例,就非线性化学指纹图谱原理进行了详细研究和讨论,并提出了计算非线性化学指纹图谱系统相似度的通用方法.利用系统相似度和欧氏距离、相关系数及夹角余弦对不同生产批次古汉养生精和18种其他样本的非线性化学指纹图谱的相似度进行了计算与分析.结果表明,相关系数和夹角余弦都不能用来作为评价非线性化指纹图谱相似度的指标.利用欧氏距离公式计算指纹图谱的非参数型相似度时,能正确反映指纹图谱的特征差异,但用其计算参数型相似度时,则有时不能正确反映样本非线性化学指纹图谱特征差异的相对程度.系统相似度能最真实反映样本指纹图谱之间差异程度,是4种相似度计算方法中最好的,可用于非线性化学指纹图谱相似度计算与评价.成功提出了一种经济、简便、易行和有效的鉴别样本真伪与评价其质量的科学方法.     

HPLC指纹图谱相似度研究

将HPLC指纹图谱看作多维空间内的向量,利用向量夹角余弦的基本公式计算两个指纹图谱间的相似度。用7个不同品种的金银花提取物的HPLC指纹图谱对计算方法进行了检验,结果表明相似度能较好地定量评价指纹图谱间的相似性,可应用于中药质量控制。     

灯盏花素注射液的HPLC指纹图谱相似性评价

指纹图谱相似性评价是中药质量控制的关键所在。本文讨论了相似度计算在中药质量评价中的应用,采用夹角余弦法和相关系数法计算相似度,并对其进行了系统聚类,得到了满意的结果。可以作为评价中药质量的一个指标。     

用热解吸处理样品-气相色谱与质谱联用法建立烟用香精指纹图谱及其在烟用香精质量控制中的应用

采用热解吸-气相色谱-质谱法,建立了香精的指纹图谱,利用夹角余弦和欧式距离法计算相似度。结果表明:利用热脱附技术能够简化样品预处理过程,保证试验的重复性,为建立指纹图谱提供可靠的数据,并避免样品预处理过程中有效成分的损失以及高沸点物质对色谱仪器的污染。夹角余弦法和欧氏距离法计算简单,两者结合能够全面考察香精的质量。     

双定性双定量相似度法评价银杏达莫注射液的高效液相色谱指纹图谱

建立了色谱指纹图谱的双定性双定量相似度评价法,并应用于银杏达莫注射液的高效液相色谱（HPLC）指纹图谱的评价。采用反相HPLC,以芦丁为参照物峰,确定了41个共有峰,建立了银杏达莫注射液的对照指纹图谱。以双定性相似度S和S′、双定量相似度C和P评价银杏达莫注射液的HPLC指纹图谱,分别考察在大峰缺失和小峰缺失两种情况下,4个相似度指标的变化特征。S能反映化学成分的分布比例,受大峰影响严重,无法反映小峰的丢失; S′对所有指纹峰等权,反映小峰缺失灵敏,二者构成双定性相似度。C能反映样品共有峰的总体含量,但受大峰影响严重,无法反映小峰的缺失; P对所有峰积分值等权,能较好地反映小峰的变动,二者构成双定量相似度。因此,由S与S′、C与P构成的双定性双定量相似度法能同时监测大峰和小峰的变动与缺失,能准确地解决色谱指纹图谱的宏观定性和定量评价问题。同时还提出了方向余弦作为对照指纹图谱的特征指纹的概念和分解相似度的概念,以此考察了各指纹峰对相似度贡献的大小及其在不同程度缺失时4种相似度的变化情况。所建立的HPLC对照指纹图谱可用于银杏达莫注射液的质量控制。     

气相色谱-质谱指纹图谱在鉴别贵州茅台酒中的应用

应用气相色谱-质谱(GC-MS)建立了贵州茅台酒的指纹图谱,确证了贵州茅台酒中35种特征组分,并采用浙江大学的中药指纹图谱相似度计算软件对样品图谱之间的相似度进行了评价和鉴别。方法的精密度及重复性良好。研究考察了38个批次贵州茅台酒、5种由贵州茅台酒股份有限公司生产的酱香型系列白酒以及12种由其他厂家生产的白酒的指纹图谱与贵州茅台酒指纹图谱模板的相似度。结果表明,通过酒的特征组分比较和基于“夹角余弦法”的指纹图谱相似度分析,可以区分贵州茅台酒和其他不同酒精度、不同香型的白酒。所建立的方法为贵州茅台酒的真伪鉴定提供了技术储备。     

顶空-气相色谱-质谱指纹图谱应用于烟用香精中主成分测定北大核心CSCD

在平衡温度为80℃,平衡时间为30min下,采用顶空分离进样,气相色谱-质谱法对9个不同批次的烟用香精的成分进行分离和鉴定。根据方法的精密度试验结果,建立了烟用香精的指纹图谱。对上述9个样品所得18个共有峰以及所建立的标准指纹图谱的数据进行比较,并利用相关系数法、夹角余弦法和欧式距离比值法计算不同样品之间的相似度。3种方法计算出的相似度变化趋势一致,均能判断出样品是否合格。     

Principle of nonlinear chemical fingerprint by using dissipative components in samples as well as calculation and evaluation of similarity

Under the conditions of constant temperature and pressure,different influences of samples with different chemical components on the mechanism of nonlinear chemical reaction will cause different changes of the potential-time relationship curve of the nonlinear chemical reaction system.Using it as the character,and using the B-Z nonlinear chemical system to use acetone and substrates in samples as main dissipative substances qua an example,the principle of nonlinear chemical fingerprint has been researched and discussed in detail.At the same time,the general method for calculating the system similarity about nonlinear chemical fingerprint was also put forward,and similarities of nonlinear chemistry fingerprints of different batches of Guhan Yangshengjing and 18 sorts of other samples were calculated by Euclidean distance,correlation coefficient,included angle cosine and system similarity,at the same time,the various similarities were analyzed.The results showed that,both of correlation coefficient and included angle cosine are unable to be used as the criterion for quantitatively evaluating the similarity of nonlinear chemistry fingerprint;as non-parametric similarity,Euclidean distance can accurately reflect the feature differences in the fingerprints,but as parametric similarity,sometimes,Euclidean distance can not accurately reflect the relative extent of characteristic difference in the nonlinear chemical fingerprints;system similarity can most truthfully reflect the characteristic difference in the nonlinear chemical fingerprints,and is the best evaluating method among the four ones.Therefore,system similarity can be used to quantitatively calculate the similar extent between the nonlinear chemical fingerprints.An economical,simple and convenient,easy pushing and effective method for identifying and evaluating complicated samples has successfully been put forward.     

化学指纹图谱的相似性测度及其评价方法

提出化学指纹图谱相似性测度概念,并以峰数弹性、峰比例同态性和峰面积同 态性为评价指标,用于多角度评价化学指纹图谱相似性测试优劣,根据这些评价指 标,用计算机仿真方法研究比较了6种相似性测度,结果表明夹角余弦测试用于度 量指纹图谱间谱峰比例的波动较适宜,峰匹配测度可较灵敏地检测小峰个数波动, 而欧氏距离测试则具有较好的综合评价能力。最后,采用实测的参麦注射液色谱分 析谱图。研究考察了上述计算机仿真实验结果,证明仿真结果符合实际情况,这表 明本研究方法可用于评价化学指纹图谱相似性测度。     

Qualitative and quantitative assessment of the HPLC fingerprints of Ginkgo biloba extract by the involution similarity method.

In this paper, we develop a new method for evaluating chromatographic fingerprints of traditional Chinese medicine (TCM) by the average involution similarity and the quantitative involution similarity. To validate this novel approach, we studied the chromatographic fingerprints of Ginkgo biloba extract by the new similarity parameters. The results were compared with those of the cosine of vectorial angle (S(F)), the correlative coefficient (r) and some other quantitative parameters, such as the apparent quantitative similarity of fingerprint R% and the average mass percentage M%. The approach represented in this paper was proved to well reflect the similarity alteration of each batch of Ginkgo biloba extract and the quantitative differences of the extracted constituents. The S(gxq) and S(gxsq) are the best qualitive and quantitative similarity parameters of all those mentioned in this paper; they can be profitably used for the qualitative and quantitative assessments of TCM chromatographic fingerprints. Through this study, the quality evaluation of TCM can be simplified by using only one parameter of with the qualitive and quantitative functions proposed in this paper.     

A new method to evaluate the similarity of chromatographic fingerprints: weighted pearson product-moment correlation coefficient

The Pearson product-moment correlation coefficient is being used to evaluate the similarity of the high-performance liquid chromatographic fingerprints of traditional Chinese medicine (TCM) in China. It is confirmed that a large range of peak areas produced the wrong results. A new algorithm concerning weighted Pearson product-moment correlation coefficient is proposed in this article. The results for both real cases and simulated data sets show that the weighted Pearson product-moment correlation coefficients allow relatively larger differences for large values, smaller differences for small values, and more reliable results than the unweighted Pearson product-moment correlation coefficients. Weight selection depends on the specific scientific problem.     

New approach on similarity analysis of chromatographic fingerprint of herbal medicine

A new approach to the construction and similarity analysis of chromatographic fingerprint for herbal medicine is presented in this paper. Samples of chuanxiong, a herbal medicine for headache, from three producing areas of China were used to evaluate the utility of this study. The samples were analyzed with high-performance liquid chromatography (HPLC) and the peak areas of the chromatograms were used to construct the fingerprints of the herbal medicines. A vector of differences was defined between the two fingerprints. The scalar mean of the difference vector was taken as a statistic and both the t-test and Bayesian hypothesis testing were implemented to provide a one-to-one comparison of the fingerprints. Compared with principal component analysis (PCA), correlation coefficient and vector cosine, the new method offers a better differentiation of the similarity or difference between the fingerprints from same sample of chuanxiong. When the new method was used in the similarity analysis of the fingerprints of chuanxiong from different production areas, a clear-cut signature was obtained that reveals the significant difference between them.