Phospholipase A₂ Inhibitors from an Erythrina Species from Samoa

Abstract

Three flavonoid phospholipase A2 (PLA2) inhibitors were isolated from a MeOH extract of the bark of the Samoan medicinal plant Erythrina variegata. Two of these compounds, 4‘-hydroxy-3‘,5‘-diprenylisoflavonone (abyssinone V) (1) and 3,9-dihydroxy-2,10-diprenylpterocarp-6a-ene (erycrystagallin) (3), have been previously reported as antimicrobial agents from plants belonging to other Erythrina species. The isoflavonone 4‘-hydroxy-6,3‘,5‘-triprenylisoflavonone (2) is a new compound, and its structure was determined by spectroscopic techniques. The IC50 values for the PLA2 enzyme were 6, 10, and 3 μM for 1−3, respectively.

Synergistic effects of mupirocin and an isoflavanone isolated from Erythrina variegata on growth and recovery of methicillin-resistant Staphylococcus aureus

“…variegata has been used as a folk medicine in tropical and subtropical regions and is known to possess pharmacological activity, including antimicrobial and anti-inflammatory effects [20,21]. In a previous report, we isolated 16 isoflavonoids from the roots of this plant and showed that 3,9-dihydroxy-2,10-di(␥,␥-dimethylallyl)-6a, 11a-dehydropterocarpan (erycristagallin) and 9-hydroxy-3-methoxy-2-␥,␥-dimethylallylpterocarpan (orientanol B) exhibited substantial anti-MRSA activity with an MIC range of 3.13-6.25 mg/ml [22].…”

Inhibition of Prostaglandin Production by a Structurally-Optimized Flavonoid Derivative, 2',4',7-Trimethoxyflavone and Cellular Action Mechanism

“…They include quercetin and some other flavones/flavonols such as scutellarein and nepetin. 4,[22][23][24] Several prenylated flavonoids including abyssinone V and papyriflavonol A were also reported as PLA 2 inhibitors. 25,26) In this respect, the present finding of new PLA 2 inhibitory flavonoid is meaningful.…”

Erythrina variegata

“…The ethanol bark extract yielded chloroform-soluble and water-soluble bases, identifi ed as erysovine and stachydrine, respectively. From the bark were isolated isofl avones (erythrinins A,B, C, osajin; alpinumisofl avone; and oxyresveratrol and dihydrooxyresveratrol) (Deshpande et al 1977 ), alkaloids (erysotine, erythratidine, epi -erythratidine and 11-hydroxy-epi -erythratidine) (Chawla et al 1988 ), three fl avonoid phospholipase A 2 (PLA 2 ) inhibitors (4′-hydroxy-3′,5′-diprenylisofl avonone (abyssinone V) and 3,9-dihydroxy-2,10-diprenylpterocarp-6a-ene (erycrystagallin) and 4′-hydroxy-6,3′,5′-triprenylisofl avonone) (Hedge et al 1997), erythrinin B ( Kobayahsi et al 1997, alpinumisofl avone and two prenylated isofl avones (erythrivarones A and B characterized as dihydroalpinumisofl avone and 4′-hydroxy-[6″,6″-dimethyldihydropyrano(2″,3″:5,6)]-[6‴,6‴-dimethyldihy dropyrano(2‴,3‴:7,8)] isofl avone, respectively) (Huang and Yen 1996 ; and warangalone (Huang and Tseng 1998 ). Isofl avonoids, eryvarin A and eryvarin B, were isolated from wood (Tanaka et al 2000 ).…”

“…Three isofl avones, abyssinone V (1), 4′-hydroxy-6,3′,5′-triprenylisofl avonone (2) and erycrystagallin (3), isolated from the bark, exhibited phospholipase A2 (PLA2) inhibition with IC 50 values of 6, 10 and 3 μM for 1 − 3, respectively (Hedge et al 1997 ). The methanol leaf extract was found to have antiinfl ammatory activity as observed by reduction of the paw oedema (Verma et al 2005 ).…”