| Liquidambar formosana Hance, belongs to Hamamelidaceae families. In traditional medicine, the whole plant can be used as medicine, which can be used to treat acute gastroenteritis, dysentery, postpartum arthritis. Its mature infructescences-Lulutong, with the effects of eliminating wind and dampness, can treat arthralgia spasm disease. Modern scientific researchs show that, in addition to the pharmacological activities, volatile oil and extracts of Liquidambar leaves also have biological activity of bacteriostasis and antioxidantion, ect. To look natural, efficient and low toxicity of natural antioxidants and provide a theoretical basis for the development of natural anti-oxidant preservative and fruit, we have a systematic study on n-butanol extracts of Liquidambar leaves in this paper.In this paper, by column chromatography, thin layer chromatography, highperformance liquid chromatography and mass spectrometry techniques to make a further separationand purification on the n-butanol extract extracts of liquidambar leaves, we get four separated monomers: quercetin-3-O-β-D-galactopyranose, gallic acid, kaempferol-3-glucoside and ellagic acid.The antioxidant activities of extracts in vitro from Liquidambar leaves (successively extracted by alcohol, n-butanol, and separated by macroporous resin) was examined by means ofl,1-diphenyl-2-picryl-hydrazyl (DPPH·), hydroxyl (·OH), superoxide anion (O2-·), reducing power. The results showed thatn-butanol extracts from Liquidambar formosana leaves possessed strong reducing power and scavenging activities against DPPH·,·OH, O2-·.The effects of different concentrations of n-butanol extracts from Liquidambar leaves (0,10,30, 50mg/100mL) on storage characteristics of post-harvest kumquat fruits were investigated. Afterpre-impregnation with 10,30,50 mg/100mL n-butanol,extracts from Liquidambar leaves, kumquat fruits were stored atroom temperature(14-16)℃. Over the storage period, mass loss rate, decay rate, hardness, total soluble solids (TSS), titratable acid(TA), malondialdehyde (MDA), superoxide dismutase (SOD), vitamin C were measured at 3-day intervals. The results showed thatn-butanol extracts from Liquidambarleaves reduced decay rate, mass lossand MDA content, delayed the decrease of hardness and TSS, TA, VC content, enhanced the activity of SOD. These results indicatedthat n-butanol extracts from Liquidambarleaves had promising applications in postharvest preservation of kumquat fruits.Ellagic acid has known existing in the Liquidambar leaves. To explorethe effect of ellagic acid on the post-harvest kimquat fruits, and to develop a safe and environmental protective antiseptic agent. kumquat fruits were pre-impregnated with different concentrations (0mg/100mL,10 mg/100mL,30mg/10(mL) ellagic acid, and stored at room temperature(14-16)℃ for 18 days. Over the storage period, mass loss rate, decay rate, firmness, TSS, TA, MDA, superoxide SOD, vitamin C were measured at 3-day intervals. Results showed that the ellagic acid can reduce decay rate and mass loss; in the 18th day, decay rate of CK, T1, T2 was respectively 5.0%,2.5%,1.0%; compared with the control group, mass loss rate of treatments with ellagic acid were lower 15.93%, 22.63%. Ellagic acid can delay the decrease of firmness, TSS, TA and vitamin C mass fraction; in the 18th day, firmness of CK, T1, T2 was2.21Kg/cm2,2.27Kg/cm2,2.40Kg/cm2, mass fraction of vitamin C was separately 14.63mg/100g,15.13 mg/100g,15.03 mg/100g; TSS contents of CK, T1, T2 were 6.8%,8.0%,8.7%; TA contents of CK, T1, T2 were 0.98%,1.54%,1.35%. And ellagic acid can inhibit the increase of MDA, enhance the activity of SOD. In the 18th day, SOD activity of T1, T2 kumquat fruits was higher than CK; contents of MDA of CK, T1, T2 were 25.33μmol/g, 22.79μmol/g,21.95μmol/g. Scores of principal component analysis had the same trend as the experiment results. |
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