摘要
植物的次生代谢产物通常是水份、温度、虫害等环境胁迫的产物,干燥过程对于新鲜采收的植物体尤其根来说,事实上就是一个干旱胁迫的过程,因此完全有可能诱导相关化学成分的形成和升高。基于这一假设,我们选用丹参(Salvia miltiorrhiza Bge.)和黄芩(Scutellaria baicalensis Georgi)开展了探索性研究。结果发现丹参的主要水溶性活性成分丹酚酸B是在干燥过程中大量形成的,在新鲜药材中含量甚微,即丹酚酸B实际上是一个采后干燥胁迫诱导产物,而非栽培期的原始积累成分。进一步研究表明不仅是丹酚酸B,所有其它丹酚酸类成分也都是在干燥过程中伴随着丹酚酸B的形成而产生的。丹参酮ⅡA和隐丹参酮等丹参酮类成分在新鲜根中有较大含量的积累,但在干燥过程中也增加近一倍以上。这些成分在干燥过程中都呈现倒"V"字形的变化趋势,增长曲线中丹酚酸B等成分的含量与样品水分呈明显负相关。黄芩药材中黄芩苷等黄酮类成分在干燥过程中也呈现类似的变化曲线。这些研究结果完全证实了我们的假设,即采后干燥早期过程对于像丹参、黄芩这样的宿根类药材,可能诱导活性成分的大量形成和升高,科学把握这一机制将大大"提高"和稳定相关药材的质量。这些研究结果和发现对于中药材GAP生产具有重要的理论和应用价值。
Drying is the most common and fundamental procedure in the post-harvest processing which contributes to the quality and valuation of medicinal plants. However, attention to and research work on this aspect is relatively poor. The general notion believes that values of bioactive components of medicinal plants were a pre-harvest accumulation and decreased in post-harvest drying process along with the increasing of temperature and the prolonging of duration. Therefore, the fundamental target of researches on bestly retain the initial levels of bioactive ingredients. However, fresh plant materials, especially roots, are still physiologically drying process of medicinal plants up to now was to from the view of plant physiology, the newly harvest active organs and the drying process is a bona fide dehydration stress to these organs. Thus, the post-harvest drying process, especially at its early stage, would induce a series of anti-dehydration mechanisms including the production or increase of related secondary metabolites of these organs. To test this hypothesis, we carried out a series of exploratory works on the post-harvest drying process of TCMs like roots of Salvia miltiorrhiza Bge. （Danshen） and roots of Scutellaria baicalensis Georgi （Huangqin） . The results demonstrated that salvianolic acid B （SaB）, the major hydrophilic bioactive component of Danshen, was a product of post-harvest drying process. A minor amount of SaB was found in fresh materials while a noticeable increase of SaB was detected in drying at 50 ~ 160 ~C. The maximal value occurred after 40 min of drying at 130 ~C and its variation showed a reverse V-shaped curve. In addition, the amounts of tanshinones were nearly doubled in the early stage of drying and their variations showed similar changing trends with drying temperatures and sample moistures. The results supported our speculation that post-harvest fresh plant materials, especially roots, were still physiologically active organs and would exhibit a series of anti-dehydration mec
出处
《中国现代中药》
CAS
2013年第3期211-218,共8页
Modern Chinese Medicine
基金
国家自然科学基金项目(3073883
81274075)
关键词
丹参
丹酚酸B
采后干燥
胁迫诱导
Danshen
Salvianolic acid B
Post-harvest drying process
Stress induction
