The diversified utilization of cotton waste or by-product will bring great practical benefit for the development of agriculture. In this work, withered cotton flowers were indicated to contain an abundance of bioactive compounds including various flavonols and anthocyanins, as is demonstrated by a targeted metabolomics approach. Subcritical water extraction (SWE), an environmentally friendly technique, was then applied to collect bioactive compounds from the red discarded flowers. Response surface methodology (RSM) was employed to determine the optimal parameters to extract these bioactive components with hot water and ethanol. When the extraction temperature was 180 °C, the ethanol concentration was 65 % and the solid-liquid ratio was 65 mL/g, the total content of phenolics and flavonoids, as well as their antioxidant activity, was the best. In addition, the flavonoid compositions of SWE extracts were identified and quantified. The most abundant flavonoid was isoquercetrin, with its content of 110.54 mg/g. This study enables comprehensive utilization of the waste resources in the cotton planting process and provides a theoretical basis for a waste-to-profit solution.

棉花废料或副产品的多样化利用将为农业发展带来巨大的实际利益。在这项工作中，已表明棉花花凋谢物含有丰富的生物活性化合物，其中包括各种黄酮醇和花色苷，这是有针对性的代谢组学方法证明的。亚临界水提取（SWE）是一种环保技术，然后应用于从废弃的红色花朵中收集生物活性化合物。响应面方法（RSM）用于确定最佳参数，以热水和乙醇提取这些生物活性成分。萃取温度为180°C时，乙醇浓度为65％，固液比为65 mL / g，酚类和黄酮类化合物的总含量及其抗氧化活性最佳。另外，鉴定并定量了SWE提取物的类黄酮成分。最丰富的类黄酮是异槲皮素，含量为110.54 mg / g。这项研究可以在棉花种植过程中全面利用废物资源，并为废物赢利解决方案提供理论依据。