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Scutellarin ( 1 ) could be hydrolyzed into scutellarein ( 2 ) in vivo and then converted into methylated, sulfated and glucuronidated forms. In order to investigate the biological activities of these methylated metabolites, eight methylated analogs of scutellarein ( 2 ) were synthesized via semi-synthetic methods. The antithrombotic activities of these compounds were evaluated through the analyzation of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (FIB). Their antioxidant activities were assessed by measuring their scavenging capacities toward 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and the ability to protect PC12 cells against H 2 O 2 -induced cytotoxicity. Furthermore, the physicochemical properties of these compounds including aqueous solubility and lipophilicity were also investigated. The results showed that 6- O -methylscutellarein ( 5 ) demonstrated potent antithrombotic activity, stronger antioxidant activity and balanced solubility and permeability compared with scutellarin ( 1 ), which warrants further development of 5 as a promising lead for the treatment of ischemic cerebrovascular disease. [ABSTRACT FROM AUTHOR]

In order to improve the biological activity and water solubility of scutellarin ( 1 ), some derivatives of its main metabolite (scutellarein) were designed and synthesized. All the compounds were tested for their thrombin inhibition activity through the analyzation of thrombin time (TT), activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen (FIB). Their antioxidant activities were assessed by measuring their scavenging capacities toward 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and the ability to protect PC12 cells against H 2 O 2 -induced cytotoxicity, their water solubility were also assessed by ultraviolet (UV) spectrophotometer. The results showed that compound 8b demonstrated stronger anticoagulant and antioxidant activity, better water solubility compared with scutellarein ( 2 ), which warrants it as a promising agent for the treatment of ischemic cerebrovascular disease. [ABSTRACT FROM AUTHOR]

O -Alkylated quercetin analogs were synthesized and their anticancer activities were assessed by a high-throughout screening (HTS) method. The structure–activity relationships (SAR) showed that introduction of long alkyl chain such as propyl group at the C-3 OH position or short alkyl chain such as ethyl group at the C-4′ OH position were very important for keeping inhibitory activities against the 16 cancer cell lines. Furthermore, when the two n -butyl groups were introduced into the C-3, C-7 or C-4′, C-7 positions, the anticancer activity was enhanced. [ABSTRACT FROM AUTHOR]