Department of Pharmaceutical Sciences & Technology, Birla Institute of Technology, Mesra, Ranchi, India.
Nat Prod Res. 2022 Sep;36(17):4421-4425. doi: 10.1080/14786419.2021.1979542. Epub 2021 Sep 20.
This study reports the influence of seasonality on the accumulation of verbascoside as a principal phenolic compound in Lindl. leaves along with possible alteration of antioxidant potentials. Leaves were collected during winter (December 2018), spring (February 2019), summer (May 2019), monsoon (July 2019), autumn (October 2019), and extracted with 95% aqueous methanol by cold maceration. The total phenolic content and antioxidant capacities (DPPH, ABTS and FRAP) were estimated by spectrophotometric technique, and verbascoside content was estimated by HPLC-PDA. Results indicate that the leaves collected during summer and winter both exhibited the highest total phenolic content verbascoside accumulation and antioxidant potentials which are significantly different ( < 0.05) than other seasons. Correlation studies further demonstrated that the total polyphenol and verbascoside contents were directly proportional to the antioxidant potentials. Thus, the study concludes that winter and summer are the best seasons for collecting leaves from this plant to obtain maximum antioxidant potential.
本研究报告了季节变化对贯叶连翘叶片中叶黄素作为主要酚类化合物积累的影响，以及抗氧化能力可能发生的变化。叶片分别于冬季（2018 年 12 月）、春季（2019 年 2 月）、夏季（2019 年 5 月）、雨季（2019 年 7 月）和秋季（2019 年 10 月）采集，并用冷浸法用 95%甲醇提取。采用分光光度法测定总酚含量和抗氧化能力（DPPH、ABTS 和 FRAP），用 HPLC-PDA 法测定叶黄呋喃苷含量。结果表明，夏季和冬季采集的叶片均表现出最高的总酚含量、叶黄呋喃苷积累和抗氧化能力，与其他季节有显著差异（ < 0.05）。相关性研究进一步表明，总多酚和叶黄呋喃苷含量与抗氧化能力直接成正比。因此，本研究得出结论，冬季和夏季是从该植物采集叶片以获得最大抗氧化能力的最佳季节。
