福建柏叶总黄酮提取工艺优化及抑菌活性研究OA

Using the leaves of Fokienia hodginsii as the research material,the ultrasound-assisted extraction process of total flavonoids was optimized through single-factor experiments and orthogonal test combined with response surface methodology.The content of flavonoids in the extract was determined by ultraviolet spectrophotometry,and its antifungal activity was evaluated.The results showed that the optimal extraction conditions for total flavonoids from Fokienia hodginsii leaves were as follows:ethanol volume fraction of 65％,liquid-to-solid ratio of 20:1(mL:g),extraction time of 61 min,ultrasound power of 460 W,and extraction temperature of 75℃.Under these conditions,the theoretical extraction yield of total flavonoids reached22.15％.The verification experiments showed an average extraction yield of 22.29％(RSD=3.52％),and the scale-up experiments yielded an average extraction rate of 22.32％(RSD=3.76％),indicating excellent stability of the process.At a mass concentration of 2 g/L,the total flavonoids had the inhibition rates of 66.77％and 61.25％against Sclerotium rolfsii and Colletotrichum gloeosporioides,with the half maximal effective concentrations(EC50)of 0.89 and1.10 g/L,respectively.The total flavonoids inhibited mycelial growth by reducing the activities of three fungal protective enzymes,namely catalase(CAT),peroxidase(POD)and superoxide dismutase(SOD),which impaired the self-detoxification capacity of the fungal cells.Meanwhile,they induced membrane lipid peroxidation and disrupted the energy metabolism process required for mycelial growth,thereby suppressing the proliferation of plant pathogenic fungi.