Biochemical Systematics and Ecology 30 (2002) 989–991 www.elsevier.com/locate/biochemsyseco Uliginosin B from Hypericum myrianthum A.B.F. Ferraz a , J. Schripsema b , A.R. Pohlmann c , G.L. von Poser a,* a Programa de Po ´s Graduac ¸a ˜o em Cie ˆncias Farmace ˆuticas, UFRGS. Av. Ipiranga, 2752, 90610-000 Porto Alegre, RS, Brazil b Setor de Quı ´mica de Produtos Naturais, LCQUI/CCT, Universidade Estadual do Norte Fluminense, Av. Alberto Lamego, 2000, 28015-620 Campos dos Goytacazes—RJ, Brazil c Departamento de Quı ´mica Orga ˆnica, Instituto de Quı ´mica—UFRGS. Av. Bento Gonc ¸alves, 9500, 91501-970, Brazil Received 25 July 2001; accepted 8 March 2002 Keywords: Hypericum myrianthum; Guttiferae; Phloroglucinol derivatives; Uliginosin B; Section Brathys; Section Trigynobrathys 1. Subject and source Hypericum myrianthum Cham. & Schlecht. (Guttiferae) is a shrub which grows only in Rio Grande do Sul State (South Brazil). Aerial parts were collected in Paraı ´so do Sul, Brazil, in July 1998, and identified by S. Bordignon (Universidade Luterana do Brasil, Canoas, Brazil). The voucher specimens (Bordignon, 1402) are deposited in the herbarium of the Federal University of Rio Grande do Sul (ICN). 2. Previous work Few among the about 20 Brazilian Hypericum species have been analyzed: fla- vonoids, xanthones and phloroglucinol derivatives were isolated from the leaves and flowers of H. brasiliense (Rocha et al., 1994, 1995, 1996) and benzopyrans were found in the aerial parts of H. polyanthemum (Ferraz et al., 2001). Eight species * Corresponding author. Tel.: +55-051-3165258; fax: +55-051-3305610. E-mail address: gilsane@farmacia.ufrgs.br (G.L. von Poser). 0305-1978/02/$ - see front matter  2002 Published by Elsevier Science Ltd. PII:S0305-1978(02)00045-5