Analytical Techniques and Pharmacokinetics of Gastrodia elata Blume and Its Constituents

Gastrodia elata Blume (G. elata), commonly called Tianma in Chinese, is an important and notable traditional Chinese medicine (TCM), which has been used in China as an anticonvulsant, analgesic, sedative, anti-asthma, anti-immune drug since ancient times. The aim of this review is to provide an overview of the abundant efforts of scientists in developing analytical techniques and performing pharmacokinetic studies of G. elata and its constituents, including sample pretreatment methods, analytical techniques, absorption, distribution, metabolism, excretion (ADME) and influence factors to its pharmacokinetics. Based on the reported pharmacokinetic property data of G. elata and its constituents, it is hoped that more studies will focus on the development of rapid and sensitive analytical techniques, discovering new therapeutic uses and understanding the specific in vivo mechanisms of action of G. elata and its constituents from the pharmacokinetic viewpoint in the near future. The present review discusses analytical techniques and pharmacokinetics of G. elata and its constituents reported from 1985 onwards

Novel Strategies Using Total Gastrodin and Gastrodigenin, or Total Gastrodigenin for Quality Control of Gastrodia elata

Gastrodia elata Blume (G. elata), a traditional Chinese medicine, is widely used for treatment of various neuro dysfunctions. However, its quality control is still limited to the determination of gastrodin. In the present study, two novel strategies based on quantitative evaluation of total gastrodin and gastrodigenin with base hydrolysis and total gastrodigenin with base-enzymatic hydrolysis followed by HPLC-FLD were put forward and successfully applied to evaluate the quality of 47 batches of G. elata from eight localities. Meanwhile, a systematic comparison of the novel strategy with the multiple markers and the Pharmacopeia method was performed. The results showed that the parishins category could be completely hydrolyzed to gastrodin by sodium hydroxide solution, and gastrodin could further utterly hydrolyze to gastrodigenin with β-d-glucosidase buffer solution. The contents of total gastrodin and gastrodigenin ranged from 1.311% to 2.034%, and total gastrodigenin from 0.748% to 1.120% at the eight localities. From the comparison, we can conclude that the two novel strategies can comprehensively reveal the characteristics of overall active ingredients in G. elata for quality control. The present study provides a feasible and credible strategy for the quality control of G. elata, suggesting a revision of the latest Chinese Pharmacopoeia or European Pharmacopoeia methods for the modernization of G. elata use

Prominent Efficiency Enhancement in Perovskite Solar Cells Employing Silica-Coated Gold Nanorods

Highly efficient planar heterojunction (PHJ) perovskite solar cells (PSCs) with a structure of ITO/PEDOT:PSS/CH₃NH₃PbI₃/PCBM/Al were fabricated by a low-temperature solution process. As employed silica-coated gold (Au@SiO₂) nanorods at the interface between the hole transport layer PEDOT:PSS and the active layer CH₃NH₃PbI₃, the average power conversion efficiency (PCE) showed over 40% enhancement, of which the average PCE was improved from 10.9% for PHJ-PSCs without Au@SiO₂ to 15.6% for PHJ-PSCs with Au@SiO₂, and the champion one up to 17.6% was achieved. Both experiment and simulation results proved that prominent efficiency enhancement comes from the localized surface plasmon resonance of Au@SiO₂ nanorods which could improve the incident light trapping as well as improve the transport and collection of charge carrier, resulting in the enhancement in device parameters. The results suggest that metal nanorods, e.g., Au@SiO₂, could be employed to fabricate high-efficiency and low-cost PHJ-PSCs