The dried leaves of Apocynum venetum L. （AVL） is a traditional Chinese medicine widely used as antihypertensive medicine in China. Accurate determination of its best harvest season is important for its effective and...The dried leaves of Apocynum venetum L. （AVL） is a traditional Chinese medicine widely used as antihypertensive medicine in China. Accurate determination of its best harvest season is important for its effective and safe use. In the present study, we developed a reliable method based on high-performance liquid chromatography-diode array detector-electro spray ionization-ion trap-time of flight （HPLC-DAD-ESI-IT-TOF） mass spectrometry and HPLC-DAD for the identification and quantification of major components in AVL leaves. Quantitative analysis of 24 samples collected weekly helped monitor the changes of compounds dynamically in AVL leaves to determine the best harvest season. A total of 30 compounds were identified, including quinic acid, five phenolic acids and 24 flavonoids. For the first time, 16 compounds were selected as marker compounds and simultaneously monitored weekly instead of monthly during the growth of the plant. The results showed that in May the leaves had the highest amount of phenolic acids, flavonoids and total compounds. Therefore, May should be the best harvest season for AVL leaves, which was distinct from previous studies. The established method was validated to be simple, accurate and precise, and thus it was of great importance for determination of the best harvest season.展开更多
In a completely randomized blocks （RCB） plot, we planted seed from the three segments of Kponan tubers： head, median and tail portions with control Krengle. Germination began 10 d and lasted 67 d. The mean sproutin...In a completely randomized blocks （RCB） plot, we planted seed from the three segments of Kponan tubers： head, median and tail portions with control Krengle. Germination began 10 d and lasted 67 d. The mean sprouting rate of the Kponan full season harvest tuber was 78.1% compared to 94% in Krengle. However, the tuber germination was progressive from head to tail with a linear evolution of the top fragments with sprouting rate up to 90% similar to Krengle. The median and distal portions sprout two and three weeks later with final raising rates reaching 68% and 71%, respectively. The full season tuber of Kponan sprouts with a good rate gave good yields for any portion of the tuber. It had a sprouting gradient oriented from the proximal portion to the distal one, while yield was better for medium seeds. The sprouting delays two weeks between proximal and medium portions and three weeks between proximal and distal portions were acceptable with regards to the total cycle of eight to nine months period. Thus, its small tubers could be planted as well as the top portion of big tuber. In terms of yield, Kponan medium seed gave the best yield 34.25 t/ha and the whole Kponan tuber yield was more than Krengle. That led to a better multiplication factor for Kponan full season tuber. The type of tuber, if available, could be used as seed for yam production. That could improve its distribution and contribute to food security.展开更多
采集四川省筠连县春、夏、秋三季共15份早白尖红茶样品,采用顶空固相萃取-气相色谱-质谱技术对红茶样品的香气成分进行测定,运用偏最小二乘-判别分析(partial least square-discriminant analysis,PLS-DA)建立不同季节茶叶判别模型,绘...采集四川省筠连县春、夏、秋三季共15份早白尖红茶样品,采用顶空固相萃取-气相色谱-质谱技术对红茶样品的香气成分进行测定,运用偏最小二乘-判别分析(partial least square-discriminant analysis,PLS-DA)建立不同季节茶叶判别模型,绘制层次聚类的树状热图确定关键香气成分在不同季节样品中的分布规律。结果表明,春季样品醇类(113.05μg/g)和酯类物质(34.92μg/g)含量明显高于夏秋两季样品,而醛类物质(23.85μg/g)明显低于夏秋两季样品,且所建PLS-DA模型可将春和夏秋两季样品明显区分。进一步分析后的分层聚类的树状热图显示,苯乙醛、橙花醇和香叶醇是春季样品区别于其它两季茶样的特征香气化合物,在此基础上可通过芳樟醇、芳樟醇氧化物Ⅰ和Ⅱ对夏、秋两季样品进行进一步区分。该研究为解析不同季节早白尖红茶香气物质提供基础研究数据,也为进一步探究筠连早白尖红茶关键香气形成机制奠定基础。展开更多
基金Initiative Drug Discovery of National Science and Technology Major Project(Grant No.2014ZX09304307-001-011)
文摘The dried leaves of Apocynum venetum L. （AVL） is a traditional Chinese medicine widely used as antihypertensive medicine in China. Accurate determination of its best harvest season is important for its effective and safe use. In the present study, we developed a reliable method based on high-performance liquid chromatography-diode array detector-electro spray ionization-ion trap-time of flight （HPLC-DAD-ESI-IT-TOF） mass spectrometry and HPLC-DAD for the identification and quantification of major components in AVL leaves. Quantitative analysis of 24 samples collected weekly helped monitor the changes of compounds dynamically in AVL leaves to determine the best harvest season. A total of 30 compounds were identified, including quinic acid, five phenolic acids and 24 flavonoids. For the first time, 16 compounds were selected as marker compounds and simultaneously monitored weekly instead of monthly during the growth of the plant. The results showed that in May the leaves had the highest amount of phenolic acids, flavonoids and total compounds. Therefore, May should be the best harvest season for AVL leaves, which was distinct from previous studies. The established method was validated to be simple, accurate and precise, and thus it was of great importance for determination of the best harvest season.
文摘In a completely randomized blocks （RCB） plot, we planted seed from the three segments of Kponan tubers： head, median and tail portions with control Krengle. Germination began 10 d and lasted 67 d. The mean sprouting rate of the Kponan full season harvest tuber was 78.1% compared to 94% in Krengle. However, the tuber germination was progressive from head to tail with a linear evolution of the top fragments with sprouting rate up to 90% similar to Krengle. The median and distal portions sprout two and three weeks later with final raising rates reaching 68% and 71%, respectively. The full season tuber of Kponan sprouts with a good rate gave good yields for any portion of the tuber. It had a sprouting gradient oriented from the proximal portion to the distal one, while yield was better for medium seeds. The sprouting delays two weeks between proximal and medium portions and three weeks between proximal and distal portions were acceptable with regards to the total cycle of eight to nine months period. Thus, its small tubers could be planted as well as the top portion of big tuber. In terms of yield, Kponan medium seed gave the best yield 34.25 t/ha and the whole Kponan tuber yield was more than Krengle. That led to a better multiplication factor for Kponan full season tuber. The type of tuber, if available, could be used as seed for yam production. That could improve its distribution and contribute to food security.
文摘采集四川省筠连县春、夏、秋三季共15份早白尖红茶样品,采用顶空固相萃取-气相色谱-质谱技术对红茶样品的香气成分进行测定,运用偏最小二乘-判别分析(partial least square-discriminant analysis,PLS-DA)建立不同季节茶叶判别模型,绘制层次聚类的树状热图确定关键香气成分在不同季节样品中的分布规律。结果表明,春季样品醇类(113.05μg/g)和酯类物质(34.92μg/g)含量明显高于夏秋两季样品,而醛类物质(23.85μg/g)明显低于夏秋两季样品,且所建PLS-DA模型可将春和夏秋两季样品明显区分。进一步分析后的分层聚类的树状热图显示,苯乙醛、橙花醇和香叶醇是春季样品区别于其它两季茶样的特征香气化合物,在此基础上可通过芳樟醇、芳樟醇氧化物Ⅰ和Ⅱ对夏、秋两季样品进行进一步区分。该研究为解析不同季节早白尖红茶香气物质提供基础研究数据,也为进一步探究筠连早白尖红茶关键香气形成机制奠定基础。
