Four new prenylated flavonoids and xanthones from the root bark of Artocarpus nobilis

Chemical investigation of the n-butanol extract from the methanol extract of the root bark of Artocarpus nobilis furnished four new prenylated flavonoids together with artonin E 2′-methylether (4), isoartonin E 2′-methylether (5), dihydroisoartonin E 2′-methylether (6), artonin V 2′-methylether (7), artobiloxanthone (1), artonin E (2) and cycloartobiloxanthone (3). All these compounds showed strong radical scavenging properties towards DPPH radical.