Flavonoids from the Leaves of Citrus aurantium (Sour Orange) and Citrus sinensis (Sweet Orange)

Abstract

Polymethoxylated flavonoids and flavonoid O- and C-glycosides were

isolated and identified from extracts of the leaves of Citrus aurantium var.

amara L (sour orange) and Citrus sinensis L (sweet orange). Altogether

twenty-three flavonoids were obtained from the two species (Table-1). This

is the first report of four of the polymethoxylated flavonoids from leaves

of C. sinenis, namely tetra-O-methyl scutallrein, queratagetin, hexamethyl

ether, isosinensetin, and sinensetin; the latter two were also obtained for

the first time from the leaves of C. aurantium. This is also the first report

of several C-glyosides of apigenin and diosmetin from the two species

(see Table-1). Furthermore, this is the first report of neodiosmin,

poncirin, narirutin glucoside and naringin glucoside from the leaves of

C. aurantium.