Optimization of quercetin extraction method in Dendrobium officinale by response surface methodology

Ultrasonic-assisted extraction of quercetin from Dendrobium officinale was optimized by response surface methodology (RSM) using high-performance liquid chromatography as a separative method. Based on single-factor experiments and two-level factorial analysis, the ethanol concentration, solid-to-liquid ratio and ultrasonic power were selected as significant response factors. The amount of quercetin that we extracted from Dendrobium officinale was 2.506–2.594 μg/g under the extraction conditions, which showed that optimization could improve the extration rate of quercetin from Dendrobium officinale. Quercetin was extracted and detected within 12 consecutive months after the germination of Dendrobium officinale by optimizing the extraction process to analyze the accumulation of quercetin. The UV-B exposure experiments showed that the Dendrobium officinale leaves have different responses to low- and high-dose UV light. The results showed that the quercetin content in Dendrobium officinale could be changed by UV-B radiation, and the response of distinct tissue parts to varying intensities of UV-B radiation was different.