Here’s a link to the study.
Shikimic acid is used as a precursor for the synthesis of oseltamivir phosphate (Tamiflu®), which is used as an anti-viral for the H5N1 strain. As concern for this virus increases, demand for medicinal products capable of treating it increases, while shikimic acid resources remain limited. In this study, for the first time shikimic acid is extracted from pine needles using water at relatively low temperature. After the subsequent evaporation, column adsorption/desorption and crystallization processes, shikimic acid crystals with a purity of over 98 % are obtained. A total recovery of approximately 85 % is reached, with the highlights of the method being simplicity, low cost and industrial practicality.
So basically, pine needle tea is a better source of shikimic acid than star anise.