The pomelo (Citrus maxima or Citrus grandis) is a crisp citrus fruit native to South and Southeast Asia. It is usually pale green to yellow when ripe, with sweet white (or, more rarely, pink or red) flesh and very thick albedo (rind pith). It is the largest citrus fruit, 15–25 centimetres (5.9–9.8 in) in diameter, and usually weighing 1–2 kilograms (2.2–4.4 lb).  The pomelo tastes like a sweet, mild grapefruit (which is itself a hybrid of the pomelo and the orange), though the typical pomelo is much larger in size than the grapefruit. Buntanbismine, a bisacridone, Baiyumine-A and -B,acridone alkaloids from Citrus grandis. A new coumarin was isolated from Citrusgrandis ‘Shatianyu’. Except for compound 6 and 8, the other compounds are firstly reported from this plant. This finding characterizes C. grandis ‘Shatianyu’ as a specie of Citrus genus. The prenylated coumarins, seco-limonins, polymethoxylated flavonol, and flavanone glycoside could be considered as chemotaxonomic markers of genus Citrus.