Abstract:
This work aimed at choosing of a suitable spectrophotometric method for the analysis of
Coreopsis tinctoria flavonoids (CTFs). Firstly, the total flavonoids in
Coreopsis tinctoria were extracted with 60% ethanol (v/v). Then petroleum ether, ethyl acetate and n-butanol were used successively to soke the total flavonoids and the petroleum ether extract, ethyl acetate extract (EAE) and n-BuOH-E extract (n-BuOH-E) were obtained separately. The content of flavonoids in EAE and n-BuOH-E were detected by classical complexation and color rendering systems including NaNO
2-Al (NO
3)
3/AlCl
3-NaOH and KAc-Al (NO
3)
3/AlCl
3, and rutin, quercetin and epicatechin (EC) were used as reference substances, respectively. The content of flavonoids in EAE and n-BuOH-E were also determined simultaneously by high performance liquid chromatography (HPLC) to verify the adaptability of the different complexation method. HPLC results showed that the content of flavonoid in EAE and n-BuOH-E was 48.43% and 43.19% respectively. By comparison, the content of flavonoids in EAE and n-BuOH-E measured with rutin KAc-AlCl
3 system was closest to that determined by HPLC. Therefore, rutin KAc-AlCl
3was considered to be the optimal method for the determination of CTFs. Then rutin KAc-AlCl
3method was used to the detection of total flavonoids in
Coreopsis tinctoria and the result was 10.65%.