| Resource of almond(Amygdalus communis L.) in Xin Jiang is abundant, but the utilization of it is only limited in nuts and its roughly processed products. Almonds green husk which contains 20-30% by weight of almond is not fully utilized.Therefore, the study on the flavonoids and the triterpene substances can provide the theoretical basis and technical support for the utilization of almond resources. In this study, the preliminary extraction, separation and determination of the active substance in the almond green husk were researched. Meanwhile, the antioxidant and antibacterial activity of almond green husk extract were evaluated. The main conclusions are as follows:1. The conventional chemical composition in almonds green husk(Xinjiang Shache county) were analyzed, The content of moisture, ash, crude fat, amino acids,sugar, polyphenol and triterpene was 3.71±0.09%, 13.30±0.18%, 1.85±0.05%, 2.08%,4.18±0.07%, 0.59±0.01% and 1.41±0.03%, respectively.2. The total flavonoids in almonds green huskwas extracted by ultrasonic-assisted organic solvent extraction. The optimized extraction condition was:extractant 100% methanol, solid-liquid ratio 1:30(g/m L), extraction time 30 min,extraction times 3, the extraction amount up to 31.94±0.36 mg/g, RSD was 1.13%(n=3).3. A high performance liquid chromatography(HPLC) method was established for separation of rutin(Rut), hyperoside(Hyp) and astragalin(Ast) in almonds green husk. The results showed that a good linear relationship(R2=0.9999) was obtained between the concentration of Rut and peak area in the range of 0.1 to 100.0 μg/m L,the recovery rate was 93.24% to 99.95%, and the RSD was 1.92%-3.37%(n=3). The good linear relationship(R2=0.9998) of Hyp and peak area in the range of 0.1 to 100.0μg/m L, the recovery rate was 94.95% to 101.54%, and the RSD was 1.17-2.95%(n=3). The good linear relationship(R2=0.9999) of Ast and peak area in the range of0.1 to 100.0 μg/m L. the recovery rate was 92.37% to 99.58%, and the RSD was1.24-3.41%(n=3). The experimental results were further verified by high mass spectrometry(HRMS).4. A HPLC method was established for separation of oleanolic acid(OA) and ursolic acid(UA) in almonds green husk. The results indicated that a good linear relationship(R2=0.9999) was obtained between the concentration of OA and peak area in the range of 5 to 500 μg/m L. The average recovery rate was 89.67% to 94.85%,and the RSD was 1.28-3.16%(n=3). The linear relationship(R2=0.9999) was obtained between the concentration of UA and peak area in the range of 5 to 500 μg/m L. The recovery rate was 88.67% to 94.77%, and the RSD was 1.07-1.92%(n=3). The experimental results were further verified by HRMS.5. The OA and UA in almonds green husk was extracted by ultrasonic-assisted organic solvent extraction. The optimized extraction condition for OA and UA was:extraction solvent, 100% ethanol; solid-liquid ratio, 1:30(g/m L); time, 30 min;extraction times, 3. Under this condition, the extraction amount of OA in almonds green husk up to 1.01±0.003 mg/g, RSD was 2.97%(n=3),and the extraction amount of UA up to 0.68±0.002 mg/g, RSD was 2.94%(n=3).6. The in vitro antioxidant activities of almonds green husk methanol and ethanol extract were evaluated through four assays including: 1,1-diphenyl-2-picrylhydrazyl(DPPH) free radical scavenging activity, hydroxyl radical(OH) scavenging activity,2,2-azino-two(3-ethyl-benzothiazole-6-sulfonic acid) two salt(ABTS) radical scavenging activity and the reducing power. The results showed that both methanol and ethanol extracts provided some degree of antioxidant capacity. But compared with the positive control including Rutin, Vitamin C and Butylated hydroxytoluene(BHT), the antioxidant activity was lower than the positive control group, which may due to the differences in the purity and chemical structure of the antioxidant substances.7. The effects of almonds green husk methanol and ethanol extracts onStaphylococcus aureus, Bacillus subtilis and Fusarium, Verticillium dahliae were evaluted by agar diffusion and growth rate methods. The results indicated that the extracts had some inhibition effect on the selected strains. |
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