Skyherb can provide luteolin, apigenin, phloretin, phloridzin, betulin in large quantity with high quality. Skyherb is a professional manufacturer of herb extract in China. Our competitive products are as follow: Grape seed extract proanthocyanidin 95% polyphenol90%/ OPCs80%/ Monomer5% polyphenol95%/ OPCs85%/ Monomer10%