Abstract:

Objective: To establish a method for determining proanthocyanidins in Yunnan pine needles and comparing their
dynamic changes in different months. Methods: The influence of the extraction solvent, the pH of solvent, the temperature and the
duration for the extraction proanthocyanidins were studied through single factor and orthogonal experiment. Taking catechin as
controls, proanthocyanidins was determined on 500 nm by Ultraviolet-Visible Spectrophotometry. Results: The optimal parameters for
the extraction of proanthocyanidins from Yunnan pine needles were 50% ethanol of pH 4.0 in the boiling water with reflux extraction,
and each extraction time duration was 3.0 h. Conclusions: The method was simple and accurate, which could be used to measure the
content of proanthocyanidins in Yunnan pine needles.

Key words: Yunnan pine needles, proanthocyanidin, content determination