Tea silkworm droppings as an enriched source of tea flavonoids

Publication date: Available online 25 January 2017 Source:Journal of Food and Drug Analysis Author(s): Tzu-Yun Chou, Meei-Ju Yang, Shih-Kung Tseng, Shoei-Sheng Lee, Chia-Chuan Chang Andraca droppings are the waste excreted by the tea biter, Andraca theae. Their chemical constituents and potential medical use, unlike those of the traditional Chinese medicine silkworm droppings, have not yet been reported. To explore new nutraceuticals, the chemical constituents of this substance were investigated as the bioactive ingredients are generally present in the ethyl acetate (EtOAc)-soluble fraction. This fraction, obtained from the ethanolic extract of dried Andraca droppings by liquid–liquid partitioning, was separated using chromatographic methods, including Sephadex LH-20, centrifugal partition chromatograph, and RP-18 columns, to obtain 14 compounds (1–14). They were characterized as 1,7-dimethyl xanthine (1), three benzoic acids (2, 3, and 5), and 10 flavonoids (4, 6–14). The amount of compounds 6, 7, and 9–14 in the droppings were in the range of 1.1–124-fold compared to those of tea leaves. In addition, 1,7-dimethyl xanthine (1) was found in Andraca droppings but was absent in tea leaves. Therefore, except for 1, which might be transformed from caffeine by microflora in the insect, the rest were not believed to be absorbed by the worm gut and are excreted directly. The present study suggests that Andraca droppings are an enriched source of the bioactive flavon...

Source: Journal of Food and Drug Analysis - January 24, 2017 Category: Food Science Source Type: research