New Pyranonaphthoquinone and Pyranonaphthohydroquinone from the Roots of Pentas longiflora

Abstract

Several quinone type compounds were isolated from the hexane, dichloromethane, and ethyl acetate extracts of the roots of Pentas longiflora. The hexane extract afforded two new compounds, [(3alpha,3'alpha,4beta,4'beta)-3,3']-dimethoxy-cis-[4,4'-bis(3,4,5,10-tetrahydro-1H-naphtho[2,3-c]pyran)]-5,5',10,10'-tetraone (1) and cis-3,4-dihydroxy-3,4-dihydromollugin (2), together with six known compounds, namely, pentalongin, mollugin, trans-3,4-dihydroxy-3,4-dihydromollugin, methyl-2,3-epoxy-3-prenyl-1,4-naphthoquinone-2-carboxylate, tectoquinone, and 3-hydroxymollugin. From the dichloromethane extract were isolated the three known compounds 3-methoxymollugin, methyl-3-prenyl-1,4-naphthoquinone-2-carboxylate, and scopoletin, while the ethyl acetate extract afforded the known 2-methoxy-3-methylanthraquinone.

Plants used to treat malaria in Nyakayojo sub-county, western Uganda

“…(TS 316) Ishagara L 4 Fever, malaria (Glover et al, 1961;Kokwaro, 1976;Adjanohoun et al, 1993;Kakudidi et al, 2000;Njoroge and Bussmann, 2006) High antiplasmodial activity (Wanyoike et al, 2004) Several quinone type compuonds isolated (El-Hadi et al, 2002) Rutaceae Toddalia asiatica Lam. (TS 391) Kabakura R 4 Malaria (Katuura et al, 2007a;Muthaura et al, 2007); cough, abdominal pain (Kokwaro, 1976;Adjanohoun et al, 1993) Significant anti-plasmodial activity (Katuura et al, 2007b), quinoline alkaloids (Ishii et al, 1991), active cpd-nitidine (Gakunju et al, 1995) Salicaceae Trimeria grandifolia ssp.…”

Traditional antimalarial phytotherapy remedies used by the Kwale community of the Kenyan Coast

“…(CM 126) Mdobe dombe (D) Herb RB Decoction, hot water extract Antiplasmodial activity (Wanyoike et al, 2004), quinoid cpds (El-Hady et al, 2002) Root decoction in milk used for malaria (Kokwaro, 1993) Rubiaceae (Kusamba et al, 1993) Whole plant used for cerebral malaria (Chhabra and Mahunnah, 1994) Rutaceae Toddalia asiatica (L.) Lam. (CM 136)…”

Antiplasmodial Quinones fromPentas longifloraandPentas lanceolata

“…In our experience, the root extracts of P. longiflora and P. lanceolata showed significant antiplasmodial activities (l " Table 1). From the root extract of P. longiflora, the naphthalene derivatives pentalongin (1) [11][12][13], psychorubrin (2) [14], and mollugin (3) (l " Fig. 1) [13,15] were chromatographically isolated, identified, and tested for antiplasmodial activities.…”