Wissadula periplocifolia (L.) C. Presl (Malvaceae) is commonly used in Brazil to treat bee stings and as an antiseptic. The antioxidant properties of its extracts have been previously demonstrated, thus justifying a phytochemical investigation for its bioactive phenolic constituents.
This has yielded five new sulphated flavonoids: 8-O-sulphate isoscutellarein (yannin) (1a); 4'-O-methyl-7-O-sulphate isoscutellarein (beltraonin) (1b); 7-O-sulphate acacetin (wissadulin) (2a); 4'-O-methyl-8-O-sulphate isoscutellarein (caicoine) (2b) and 3'-O-methyl-8-O-sulphate hypolaetin (pedroin) (3b) along with the known flavonoids 7,4'-di-O-methyl-8-O-sulphate isoscutellarein (4), acacetin, apigenin, isoscutellarein, 4´-O-methyl isoscutellarein, 7,4'-di-O-methylisoscutellarein, astragalin and tiliroside. The compounds were isolated by column chromatography and identified by NMR (¹H, (13)C, HMQC, HMBC and COSY) and LC-HRMS. A cell based assay was carried out to evaluate the preliminary cytotoxic properties of the flavonoids against UVW glioma and PC-3M prostate cancer cells as well as non-tumour cell lines. The obtained results showed that acacetin, tiliroside, a mixture of acacetin + apigenin and the sulphated flavonoids 2a + 2b exhibited inhibitory activity against at least one of the cell lines tested. Among the tested flavonoids acacetin and tiliroside showed lower IC50 values, presenting promising antitumor effects.
Molecules (Basel, Switzerland). 2015 Nov 09*** epublish ***
Yanna C F Teles, Carolina Campolina Rebello Horta, Maria de Fátima Agra, Weam Siheri, Marie Boyd, John O Igoli, Alexander I Gray, Maria de Fátima Vanderlei de Souza
Post-Graduation Program in Development and Technological Innovation in Medicines, Health Sciences Center, Federal University of Paraiba, 58051-900 João Pessoa, PB, Brazil. Capes Foundation, Ministry of Education of Brazil, Caixa Postal 250, 70359-970 Brasília, DF, Brazil. Biotechnology Center, Federal University of Paraiba, 58051-900 João Pessoa, PB, Brazil. Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, G4 0RE Glasgow, UK. Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, G4 0RE Glasgow, UK. Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, G4 0RE Glasgow, UK. Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, G4 0RE Glasgow, UK. Post-Graduation Program in Development and Technological Innovation in Medicines, Health Sciences Center, Federal University of Paraiba, 58051-900 João Pessoa, PB, Brazil.