| Millettia Speciosa Champ. is a kind of traditional Chinese medicine. Research about Millettia Speciosa Champ. is limited domestic and overseas. In this paper, both water extracts and ethanol extracts were studied. The chemical and physical characters of glycoprotein from the water extracts of Millettia Speciosa Champ. were learnt through purification and structural identification. The primary antioxidant activities of ethanol extracts were also studied.The chemical composition of Millettia Speciosa Champ. was determined as: 5.92 % of moisture, 7.54 % of protein, 47.62 % of fiber, 0 % of fat, 2.33 % of ash and 28.70 % of total sugar. Based on single factor test, orthogonal test was used to optimize the extract condition of glycoprotein according to the extract yield. The optimal condition was: extraction time: 30 min; solvent-material ratio: 20:1; ultrasonic power: 800 W; extraction temperature: 55 ℃. The glycoprotein yield was 2.51 % under the optimal condition. Glycoprotein of Millettia Speciosa Champ.(MSCG) was purified by ultrafiltration, chromatography Sephadex G-75 and ODS, resulting in two purified fractions MSCG-1 and MSCG-2. According to SDS-PAGE and HPLC analysis, both MSCG-1 and MSCG-2 were pure. The average molecular weight of MSCG-1 was 62.0 k Da, while MSCG-2 was 1.94 k Da. The oxygen radical absorbance capacity(ORAC) of MSCG-1 was 56.10±18.49 μmol Trolox/g while MSCG-2 was 1077.19±60.82 μmol Trolox/g.The structural characterization of MSCG-1 was as following: protein content was 50.22 % and was mainly constructed by Asp, Glu and Ser; sugar content was 38.07 % and was consisted of rhamnose, arabinose, fucose, xylose, mannose, glucose, galactose with a molar ratio of 1.27 : 25.55 : 1.16 : 1 : 4.12 : 7.42 : 21.60; mainly composed of 1,4,6-linked galactose and 1-linked arabinose. The structural characterization of MSCG-2 was as following: protein content was 69.37 % and was mainly constructed by Pro and Cys; sugar content was 6.70 % and was consisted of rhamnose, arabinose, fucose, xylose, mannose, glucose, galactose with a molar ratio of 1.84 : 5.35 : 1.17 : 1 : 3.13 : 48.62 : 3.00; mainly composed of 1, 6-linked glucose. O-link bond was found both in MSCG-1 and MSCG-2.The ethanol extract was extracted by petroleum ether, ethyl acetate and butanol in sequence, resulting in three fractions which were MPEL, MEAL and MBL. The total phenols, flavonoids and saponins in MPEL were 415.8, 34.0 and 32.6 mg/g respectively; in MEAL were 468.2, 118.6 and 87.3 mg/g respectively; in MBL were 294.2, 51.0 and 8.5 mg/g respectively. Their antioxidant activities were estimated, MEAL exhibited the best antioxidant activities in all evaluation indexes. The ORAC value of MEAL was 3920.81±88.86 μmol Trolox/g; ABTS·+ scavenging ability was 1285.14±22.11 μmol Trolox/g; DPPH·scavenging ability was 93.24±0.27 % at the concentration of 0.75 mg/m L; reducing power was 1.28 at the concentration of 1.25 mg/m L. C18-SPE was used to primarily purify MPEL, MEAL and MBL. The purification effect was affirmative according to the HPLC analysis. |
PDF Full Text Request