Materials and methods
Extraction and characterization of loquat tea.
Extraction and characterization of loquat tea was
reported previously.4,5) In brief, loquat leaves were
roasted to 350 °C for 30 min in a ceramic vessel. Both
fresh leaves and roasted loquat tea were then boiled at
100 °C for 15 min. The supernatant of loquat tea was
further separated by MCI gel-CHP20P to obtain A
(water extract), B (30% EtOH extraction), C (50%
EtOH), and D fraction (100% acetone). The fraction C
containing highest polyphenols was further separated
by ODS gel column to obtain C1-C9 fractions eluted
by 10–90% MeOH. The extracts were analyzed with
HPLC to identify the compounds known in fresh leaves
as described previously.4) All extracts and fractions
were evaporated and stored at −20 °C for less than two
months.