Houttuyniae Herba (HH) refers to the dried aerial part of Houttuynia cordata Thunb. (DHC) or the fresh whole grass of Houttuynia cordata Thunb. (FHC), where DHC are harvested in summer and FHC around the year. However, harvest seasons and processing methods (i.e., medicinal parts and drying process) might affect the quality of HH. To compare the essential oils (EOs) of DHC and FHC and their two harvest seasons, GC-MS analysis combined with chemometric analysis was applied. The results showed that the oil yield of FHC (0.076 ± 0.030%) was higher than that of DHC (0.038 ± 0.029%), and oil yield was higher in summer than in autumn (0.044 ± 0.029% for DHC1, 0.036 ± 0.028% for DHC2, 0.084 ± 0.026% for FHC1, and 0.067 ± 0.033% for FHC2, respectively). Moreover, hierarchical cluster analysis (HCA) and principal component analysis (PCA) successfully distinguished the chemical constituents of DHC and FHC oils. Additionally, according to orthogonal partial least squares discriminant analysis (OPLS-DA), eleven components were selected as chemical markers for discriminating DHC and FHC, and two and four chemical markers for discriminating two harvest seasons of DHC and FHC, respectively. Among these markers, the average contents of α-pinene, limonene, β-phellandrene, α-terpineol, 4-tridecanone, and ethyl decanoate were higher in FHC oils. In contrast, the average contents of nonanal, 1-nonanol, β-cyclocitral, n-hexadecanoic acid, and octadecanol were higher in DHC oils. Additionally, the contents of 4-tridecanone and ethyl decanoate were both higher in DHC1 oils than in DHC2 oils. Moreover, the contents of β-myrcene and β-phellandrene were higher in FHC1 oils, while the contents of 2,6-octadien-1-ol, 3,7-dimethyl-, acetate, and (z)-phytol were higher in FHC2 oils. For these reasons, this study provides a scientific basis for quality control and clinical medication.

中文翻译：

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鱼腥草精油的比较。基于 GC-MS 和化学计量分析的不同加工方法和收获季节

鱼腥草草（HH）是指的干燥地上部分蕺藤。(DHC) 或鱼腥草的新鲜全草拇指。(FHC)，夏季收获 DHC，全年收获 FHC。然而，收获季节和加工方法（即药用部位和干燥过程）可能会影响 HH 的质量。为了比较 DHC 和 FHC 的精油 (EO) 及其两个收获季节，应用了 GC-MS 分析与化学计量分析相结合。结果表明，FHC的出油率（0.076±0.030%）高于DHC（0.038±0.029%），夏季出油率高于秋季（DHC1为0.044±0.029%，0.036±0.028%） DHC2 为 0.084 ± 0.026%，FHC1 为 0.067 ± 0.033%）。此外，层次聚类分析 (HCA) 和主成分分析 (PCA) 成功区分了 DHC 和 FHC 油的化学成分。此外，根据正交偏最小二乘判别分析(OPLS-DA)，选择11个成分作为区分DHC和FHC的化学标记，分别选择2个和4个作为区分DHC和FHC两个收获季节的化学标记。在这些标记中，平均含量α-蒎烯、柠檬烯、β-水芹烯、α-萜品醇、4-十三烷酮和癸酸乙酯在 FHC 油中含量较高。相比之下，DHC 油中壬醛、1-壬醇、β-环柠檬醛、正十六烷酸和十八醇的平均含量较高。此外，DHC1 油中 4-十三酮和癸酸乙酯的含量均高于 DHC2 油。此外，内容β月桂烯和β水芹烯均FHC1油更高，而2,6-辛二烯-1-醇，3,7-二甲基- ，乙酸酯，和（Z）在-phytol较高的内容FHC2 油。由于这些原因，本研究为质量控制和临床用药提供了科学依据。