不同药用部位及不同采收期疏花荠苧总黄酮含量动态比较

目的：研究不同药用部位及不同采收期疏花荠芋总黄酮的含量变化,为确定疏花荠芋药材药用部位及最佳采收期提供依据。方法：采用分光光度法测定总黄酮含量。结果：不同采收期疏花荠芋药材总黄酮含量以9月为高;不同药用部位,叶中总黄酮含量明显高于茎、根。结论：建议疏花荠芋药材采收以9月地上部分为宜。     

野生与栽培夏枯草不同生长期3种酚酸成分含量动态研究

目的通过研究野生与栽培夏枯草全草不同生长期的指纹图谱及3种酚酸成分含量动态变化规律,确定夏枯草全草的最佳采收期,研究全草的药用价值,并对野生与栽培夏枯草进行差异性比较。方法采用UPLC法测定野生与栽培夏枯草全草的指纹图谱及迷迭香酸、异迷迭香酸苷和咖啡酸的含量。结果夏枯草全草不同生长时期3种酚酸成分的含量差异较大;野生夏枯草与栽培夏枯草指纹图谱存在一定差异,3种酚酸成分含量差异不明显。结论夏枯草全草的最佳采收期在6月中上旬,野生与栽培夏枯草全草均具有一定的入药价值。     

地椒中总黄酮的含量测定及其体外抗氧化活性的研究

目的 测定地椒中总黄酮的含量并研究其清除DPPH自由基的活性.方法 采用紫外可见分光光度法测定地椒提取物中总黄酮的含量;用DPPH自由基清除法测定地椒中总黄酮的抗氧化活性.结果 不同产地、采收期地椒药材中总黄酮的含量差异较大,结合抗氧化实验结果可见:甘肃庆阳产地椒中总黄酮的含量最高,最佳采收期为9月.结论 所用方法简便、准确,可作为地椒中总黄酮的含量测定方法;产地和采收期对地椒中总黄酮的含量影响较大;地椒总黄酮具明显的体外抗氧化活性.     

野生与栽培黄芩中总黄酮及黄芩苷含量的比较研究

目的：比较野生黄芩与栽培黄芩中总黄酮及黄芩苷的含量。方法：采用紫外分光光度法测定黄芩中总黄酮的含量,采用高效液相色谱法测定黄芩苷的含量,比较野生黄芩与人工栽培黄芩中总黄酮及黄芩苷含量的差异。结果：野生黄芩总黄酮的含量为16.31±2.91%,栽培黄芩总黄酮的含量为25.60±3.03%,存在显著性差异（P=0.005）;野生黄芩黄芩苷的含量为8.46±1.23%,栽培黄芩黄芩苷的含量为11.66±1.36%,存在显著性差异（P=0.016）。栽培黄芩总黄酮和黄芩苷的含量显著高于野生黄芩。结论：从总黄酮和黄芩苷含量角度而言,栽培黄芩优于野生黄芩,可以替代野生黄芩用于临床和实际应用。     

不同采收期的芒果叶中总黄酮的变化规律研究

目的研究不同采收期的芒果叶中总黄酮的变化规律。方法采用乙醇回流法从芒果叶中提取黄酮类物质,并用紫外分光光度法测定不同采收期芒果叶的总黄酮含量。结果芒果叶中总黄酮的含量随采收季节不同呈一定幅度变化,其中以1、11月总黄酮含量最高,5～7月含量较低。结论不同采收期是影响芒果叶中总黄酮质量的重要阂素。     

浙江产玄参不同采收季节哈巴俄苷和肉桂酸含量变化分析

目的:测定浙江产栽培玄参不同采收期、不同植物部位以及不同采收期野生玄参主根中哈巴俄苷和肉桂酸的含量.方法:Zorbax ODS分析柱(250 mm×4.6 mm,5 μm),流动相为乙腈和1%醋酸水溶液线性梯度洗脱 (20:80:50:50) (20 min),流速为1 ml·min-1,室温,检测波长为278 nm.结果:哈巴俄苷与肉桂酸回收率分别为97.7%和102.3%,RSD分别为0.68%和1.93%.测定了浙江产16份玄参样品中哈巴俄苷和肉桂酸的含量.结论:野生玄参和栽培玄参的次生代谢产物累积的周期不同,11月份采收的野生玄参中哈巴俄苷的含量比较高;而9月份采收的栽培玄参中哈巴俄苷的含量比较高.根茎、子芽也可以考虑作为玄参的药用部位.     

不同采收期春柴胡中总黄酮的含量测定

目的: 测定不同产地、不同采收期春柴胡中总黄酮的含量.方法:采用比色法,检测波长为 510 nm.结果与结论:不同产地、不同采收期春柴胡中总黄酮的含量差异较大.     

野马追最佳采收期的研究

目的：研究野马追生长过程中总黄酮含量的变化规律，确定野马追的最佳采收期。方法：用紫外分光光度法测定不同采收期野马追中的总黄酮含量。结果：不同采收期的野马追中，总黄酮含量以7月20日最高，即顶花初开时。结论：建议采收野马追应在顶花将开前2～3d开始收割，顶花开后2—3d内收割完毕。     

罗布麻叶总黄酮类化合物的提取及含量测定

目的建立罗布麻叶总黄酮含量的测定方法,并用此方法优化罗布麻叶的提取方法.方法以槲皮素为标准品,采用紫外分光光度法对罗布麻叶提取物中主要成分黄酮类化合物的含量进行测定,并比较75%乙醇回流、超声、索氏以及水提,超声5种提取方法所得提取物中总黄酮的含量.结果槲皮素的线性范围为2.96-22.20 mg·L-1,回归方程为Y=11.54X+0.175(r=0.999 96),75%乙醇超声2 h所得提取物中黄酮类化合物含量最高(13.07%).结论紫外分光光度法可以作为罗布麻叶的质量控制方法之一,用75%乙醇超声2 h提取所得的提取物中黄酮类化合物的含量较高.     

恩施产堇叶碎米荠中氨基酸及活性成分比较

目的 评估堇叶碎米荠食用和药用价值.方法 分别采用酸水解氨基酸自动分析法、原子荧光光度法、紫外分光光度法和苯酚-硫酸法,分析不同生境条件下,堇叶碎米荠氨基酸、硒、总黄酮和粗多糖含量.结果 堇叶碎米荠作为一种新食品原料,其抽苔期栽培植株和野生植株全氨基酸含量分别为18.55g/100g和20.53g/100g,而在期栽培植株中含量较低(8.44g/100g);除脯氨酸外,抽苔期的栽培与野生植株样品中其它16种氨基酸含量基本相同,但前者必需氨基酸所占比例(43.29%)高于后者(38.48%).值得注意的是野生植株样品中含有丰富的脯氨酸,其含量高达2.88%,是大棚栽培样品的3~5倍.大棚补硒栽培的2个样品硒含量分别为199μg/100g和194μg/100g,而生长于高硒地带上的野生植株样品(ES-wild)硒含量为177μg/100g.结荚期栽培植株的总黄酮含量(529mg/100g)高于野生植株(478mg/100g))和抽苔期栽培植株(474mg/100g),其粗多糖含量(1.05g/100g)也略高于野生植株(0.97g/100g)和抽苔期栽培植株(0.87g/100g).结论 堇叶碎米荠作为功能性食品原料开发利用,需考虑不同生境条件对其化学成分的影响.     

Content and Composition of M. officinalis Oil in Relation to Leaf Position and Harvest Time1

The content and composition of the essential oil in the leaves of M. OFFICINALIS L. (Lamiaceae) cultivated under Mediterranean climatic conditions were investigated. Different leaf positions and different times of harvest during the year and during the day were considered. It was shown that in the terminal leaves, the content of essential oil was more than 0.1% higher than in the others. The results obtained also indicated a variation of the oil composition. The favourable climatic and environmental conditions of the Ebro-Delta in Spain permitted four harvests per year with a maximum of 0.4% essential oil in September. To reduce losses of volatile terpenoids, a harvest in the morning during summertime is recommended.     

树龄、采收期和干燥方法对银杏叶中总内酯的影响

目的 对银杏叶中总内酯进行研究,为银杏叶资源的合理利用提供科学依据.方法 采用HPLC-ELSD法测定不同树龄、采收季节和干燥方法的银杏叶中总内酯.结果 树龄小于10年,5～7月采收,干燥方法为晒干的银杏叶中总内酯含量较高.结论 银杏叶中总内酯的含量受树龄、采收季节和干燥方法的影响,应合理采收银杏叶,保护银杏叶资源.     

湘产南方红豆杉中紫杉醇含量动态变化的研究

目的掌握湘产南方红豆杉不同生长季节的枝叶中紫杉醇含量的动态变化规律,确定最佳采收期。方法高效液相色谱法对湘产南方红豆杉不同生长季节的枝叶中紫杉醇含量进行了测定和分析。结果从3月新枝叶萌发至6月份紫杉醇的含量逐渐增加,6月份枝叶中紫杉醇含量最高,7月份开始紫杉醇的含量逐渐减少。结论6月份为湘产南方红豆杉枝叶的最佳采收期。     

Determination of Flavonoids,Tannins and Ellagic acid in leaves from<Emphasis Type="Italic">Rubus</Emphasis> L. species

This paper describes the quantitative determination of flavonoids, tannins and ellagic acid in the leaves from wild and cultivated variations of Rubus L. species (Rosaceae): raspberry (2 wild and 13 cultivars) and blackberry (3 wild and 3 cultivars). The content of flavonoids was analyzed using spectrophotometric (the Christ-Mullers method) and HPLC analysis after acid hydrolysis. The content of tannins was determined by the weight method, with hide powder, described by German Pharmacopoeia 10 (DAB 10). Ellagic acid content was examined using the HPLC method after acid hydrolysis. Flavonoid content, determined using the Christ-Muller's method was higher for the blackberry leaves than for the raspberry leaves and varied between 0.46% and 1.05%. Quercetin and kaempferol were predominant in all samples analyzed using the HPLC method. The highest flavonoid content was found in the leaves of R. nessensis (1.06%); with results in all of the examined samples varying between 0.27% and 1.06%. The concentration of ellagic acid in all species was determined after acid hydrolysis and ranged from 2.06% to 6.89%. The leaves of raspberries are characterized by greater amounts of tannins (varying between 2.62% and 6.87%) than the leaves of other species. The results from this study indicate that the analyzed species are a rich source of flavonoids, ellagic acid and tannins, which may be used for the quality assessment of Rubus L. species leaves.     

Frequency and timing of leaf removal affect growth and podophyllotoxin content of Podophyllum peltatum in full sun

Podophyllotoxin is a pharmaceutical compound found in leaves and rhizomes of American mayapple (P. peltatum L.), a species being investigated as an alternative to that of the Indian mayapple (P. emodi). Leaves alone can serve as a renewable source of podophyllotoxin (and other lignans) leaving rhizomes undisturbed to produce leaf biomass in subsequent years. It is not known, however, how frequently or severely plants can be defoliated without adversely affecting future plant growth, lignan content, or podophyllotoxin yield (g.m(-2)). This study compared harvest strategies that were mild to severe in frequency and timing of leaf removal. A wild population in full sun was subjected to leaf removal treatments of varying frequency (every year, every 2nd or 3rd year) and timing (early or late). Control plots not previously harvested were included every year. Plots were 1.0 m2 and established during spring of 2001. Duration of the study was four years. P. peltatum plants did not tolerate the most severe harvest treatment: annual harvest frequency in combination with early harvest time. Early annual harvests reduced total leaf dry mass and total leaf area in a consistent and linear manner. In contrast, plants tolerated annual harvests when conducted late in the growing season and tolerated early harvests when conducted every 2nd or 3rd year. The number of sexual shoots was reduced to zero by early annual harvests. Podophyllotoxin content was 2.7 to 6.5 times greater in leaves harvested early compared to those harvested late, though content was significantly greater in only two out of four years. In conclusion, we can recommend leaf removal every year from well-established P. peltatum populations grown in full sun if harvests are conducted late in the growing season. This harvest strategy ensures maximum podophyllotoxin yield without jeopardizing future leaf biomass yield. Leaves harvested early appear to have greater podophyllotoxin content, but we discourage early harvest every year. Instead, our results indicate that leaves can be harvested early every other year without reducing long-term performance of P. peltatum populations.     

杜仲采收期的实验研究

目的　探讨杜仲皮与叶的最佳采收期。方法　通过对杜仲皮和叶在不同季节总浸出物含量及有效成分的测定,比较在不同季节的差异。结果　不同季节的杜仲皮其浸出物总量及有效成分没有显著差异,而杜仲叶则有明显差异,以夏季为最高。结论　杜仲皮在春季、夏季、秋季均可采收,而杜仲叶以夏季 8～ 9月采收为最佳。     

野生与栽培刺五加叶的质量评价

目的：对野生与栽培刺五加叶的质量进行评价。方法：以总皂苷为指标，用比色法对野生和栽培刺五加叶中皂苷的含量进行测定。结果：野生刺五加叶中皂苷的含量显著高于栽培刺五加叶。结论：说明刺五加叶的质量与其生态环境有密切关系，为刺五加的开发利用提供了科学依据。