In the present study, we aimed to detect and quantify cyclo-dopa amides in Portulaca oleracea L. Together with four known ones （oleracein A-D）, we further identified eight new cyclo-dopa amides, named oleracein H-O,...In the present study, we aimed to detect and quantify cyclo-dopa amides in Portulaca oleracea L. Together with four known ones （oleracein A-D）, we further identified eight new cyclo-dopa amides, named oleracein H-O, using an HPLC-DAD combined with an improved HPLC-ESI-MS/MS method. A standardized HPLC fingerprint of cyclo-dopa amides was generated for the first time through analyzing 11 batches ofP. oleracea. Simultaneously, the contents of two major amides, oleracein A （OA） and oleracein B （OB）, and the total amides （TID） were determined. Our results showed that the contents of OA and OB of P. oleracea ranged from 35.00 to 151.93 mg/kg and from 40.00 to 150.44 mg/kg, respectively. Moreover, TID ranged from 314.16 to 928.60 mg/kg （calculated by OA）, or from 475.83 to 1393.00 mg/kg （calculated by OB）. Taken together, our newly develooed method could be used for the aualitv assessment and oualitv control of this herb.展开更多
In this paper, we report a technique for the surface modification of poly-(p-phenylene terephthamide)(PPTA) powder coated with polydopamine(PDOPA). We used air oxidation to self-polymerize dopamine(DOPA) to ensure tha...In this paper, we report a technique for the surface modification of poly-(p-phenylene terephthamide)(PPTA) powder coated with polydopamine(PDOPA). We used air oxidation to self-polymerize dopamine(DOPA) to ensure that the PPTA powder was coated. Our results indicate that the modified surface of PPTA powder enhances compatibility with the polymer matrix without damaging its structure. Additionally, it is possible to control the coating thickness of PDOPA by regulating the reaction time. The modified PPTA powder improved the comprehensive property of ethylene-propylene-diene-terpolymer grafted maleic anhydride(EPDM-g-MAH), and it proved that this method can enhance the strength and electric insulativity of EPDM-g-MAH.展开更多
基金National Natural Science Foundation of China(Grant No.81073005)Shandong Province Young and Middle-Aged Scientists Research Awards Fund(Grant No.BS2010YY032)+1 种基金Scientific Research Foundation for Returned Overseas Scholars,Ministry of Education of China(Grant No.42)Innovation Project of Shandong University(Grant No.2012TS102)
文摘In the present study, we aimed to detect and quantify cyclo-dopa amides in Portulaca oleracea L. Together with four known ones （oleracein A-D）, we further identified eight new cyclo-dopa amides, named oleracein H-O, using an HPLC-DAD combined with an improved HPLC-ESI-MS/MS method. A standardized HPLC fingerprint of cyclo-dopa amides was generated for the first time through analyzing 11 batches ofP. oleracea. Simultaneously, the contents of two major amides, oleracein A （OA） and oleracein B （OB）, and the total amides （TID） were determined. Our results showed that the contents of OA and OB of P. oleracea ranged from 35.00 to 151.93 mg/kg and from 40.00 to 150.44 mg/kg, respectively. Moreover, TID ranged from 314.16 to 928.60 mg/kg （calculated by OA）, or from 475.83 to 1393.00 mg/kg （calculated by OB）. Taken together, our newly develooed method could be used for the aualitv assessment and oualitv control of this herb.
基金supported by the National Natural Science Foundation of China (51273157)Program for New Century Excellent Talents in University (NCET-10-0659)Key Program of Natural Science Foundation of Hubei Province of China (2013CFA020)
文摘In this paper, we report a technique for the surface modification of poly-(p-phenylene terephthamide)(PPTA) powder coated with polydopamine(PDOPA). We used air oxidation to self-polymerize dopamine(DOPA) to ensure that the PPTA powder was coated. Our results indicate that the modified surface of PPTA powder enhances compatibility with the polymer matrix without damaging its structure. Additionally, it is possible to control the coating thickness of PDOPA by regulating the reaction time. The modified PPTA powder improved the comprehensive property of ethylene-propylene-diene-terpolymer grafted maleic anhydride(EPDM-g-MAH), and it proved that this method can enhance the strength and electric insulativity of EPDM-g-MAH.
