Pyrone and Unusually Furanone-substituted Flavones from the Leaves of Hoslundia opposita

Abstract

Two new unusual 6-furanoflavones, hoslunfuranine (5) and 5-O-methylhoslunfuranine (6), were isolated from the leaves of Hoslundia opposita Vahl.. Four known methylpyranoflavonic analogues [hosloppin (1), hoslundin (2), 5-O-methylhoslundin (3), oppositin (4)], all specific of the species, were also obtained. Their structures were established on the basis of their spectroscopic data. In vitro cytotoxic, trypanocidal, and leishmanicidal activities of compounds 1 and 3 to 6 were evaluated. Compounds 4 and 6 exhibited leishmanicidal potential in the micromolar range.

A review for selecting medicinal plants commonly used for malaria in Uganda

“…stapf (Poaceae) Vinitketkumnuen et al, 1994;Viana et al, 2000;Sacchetti et al, 2005;Adeneye and Agbaje. 2007;Fandohan et al, 2008;Silva et al, 2008;Blanco et al, 2009;Pereira et al, 2009;Figueirinha et al, 2010;Olivero-Verbel et al, 2010;Bassolé et al, 2011;Stangeland et al, 2011;Machado et al, 2012;Francisco et al, 2013;Gbenou et al, 2013;Ukpai and Amaechi, 2012;Bao et al, Adia et al, 2014;Ekpeyong et al, 2015;Sagradas et al, 2015;Chukwuocha et al, 2016;De Silva et al, 2017;Philip et al, 2017;Venzon et al, 2018 Hoslundia Weenen et al, 1990;Achenbach et al, 1992;Gundidza et al, 1992;Mujovo et al, 2008;Usman et al, 2010;Gathirwa et al, 2011;Lacroix et al, 2011;Stangeland et al, 2011;Salame et al, 2012;Asiimwe et al, 2013;Adia et al, 2014;Babarinde et al, 2014;Kamatenesi et al, 2011;Anywar et al, 2016;Opio et al, 2017…”

The Botanical, Chemical and Ethnobotanical Diversity of Southern African Lamiaceae

“…Three flavonoids, hoslundin, hoslundal and hoslunddiol, as well as two pyrone-substituted flavonoids—oppositin and 5- O -methylhoslundin—have been isolated from Cameroonian Hoslundia opposita Vahl [ 114 , 116 ]. In a later study by Salame et al (2012) [ 310 ], two unusual 6-furanoflavones (hoslunfuranine and 5- O -methylhoslunfuranine), along with the known methylpyranoflavonic analogues were isolated from the leaves of H. opposita . Furthermore, the antileishmanicidal capabilities of select compounds were investigated; two of which exhibited potential in the micromolar range.…”

The uniqueness and therapeutic value of natural products from West African medicinal plants. Part I: uniqueness and chemotaxonomy

“…Korupensamine A (34) and B (35) have been isolated from both Ancistrocladus guineensis (Nigeria) 42 and its sister species A. korupensis (Cameroon), 43 while ancistroguineines A (36) and B (37), ancistrotectorine (38) and ancistrobrevine B (39) were unique to the Nigerian species. 44 The chemistry and biological activities of the other naphthyl isoquinolines isolated from Central and East Africa have been discussed in recently published reviews. 5d,7 Other rare compound types identied from West African ora are the unusual furanone-substituted avones 44 and divanilloylquinic acids.…”

“…44 The chemistry and biological activities of the other naphthyl isoquinolines isolated from Central and East Africa have been discussed in recently published reviews. 5d,7 Other rare compound types identied from West African ora are the unusual furanone-substituted avones 44 and divanilloylquinic acids. 45 The former has been isolated from the leaves of Hoslundia opposita (Lamiaceae) while the latter was derived from Fagara zanthoxyloides (Rutaceae), a plant species used in folk medicine for its antisickling properties in Burkina-Faso and other West African countries.…”