Preparation
Method 1: A method for preparing Periplocoside, comprising the following steps:
1) Drying the roots or stems of *Salix viminalis* at a predetermined temperature, and pulverizing the dried roots or stems to obtain *Salix viminalis* root or stem powder;
2) Placing a predetermined weight of *Salix viminalis* root or stem powder into a container, and adding a predetermined amount of ethanol solution to the container and stirring to obtain an ethanol mixture of *Salix viminalis* root or stem powder;
3) After ultrasonic extraction of the ethanol mixture of *Salix viminalis* root or stem powder, cooling it to room temperature, filtering it, and concentrating the filtrates to dryness to obtain salicylic acid. Method 2: A method for preparing cypermethrin, comprising the following steps: 1) Extraction of Perilla frutescens root bark: Perilla frutescens root bark is extracted using 40%–80% ethanol or 40%–100% methanol (v/v) as the extraction solvent. After extraction, the solvent is evaporated, water is added, and the mixture is filtered or centrifuged to obtain a clear aqueous solution of Perilla frutescens root bark; 2) Macroporous resin adsorption separation: The aqueous solution of Perilla frutescens root bark is adsorbed onto a macroporous resin and eluted with a gradient of 10%–95% ethanol. Each eluted fraction is collected, concentrated, and subjected to thin-layer chromatography. Color is developed using a cardiac glycoside-specific colorimetric reagent. The fractions containing cardiac glycosides are collected and combined; 3) High-performance liquid chromatography (HPLC) preparation and separation: The cardiac glycoside fraction was prepared by HPLC using a reversed-phase column with a mobile phase of methanol:water at a volume ratio of 30-60:70-40 or acetonitrile:water at a volume ratio of 15-40:85-60. The elution curve was monitored at 217-220 nm using an ultraviolet detector to guide product collection. The collected solution was concentrated and dried to obtain Periplocoside.
