Taigen Biotechnology Co. Ltd. (TGBJ), of Taipei, Taiwan, said its wholly owned subsidiary, Taigen Biopharmaceuticals Co. (Beijing) Ltd., executed an equity purchase agreement to sell its 9 percent equity stake in Dongguan HEC Taigen Biopharmaceuticals Co. Ltd., a joint venture between TGBJ and HEC, to Yichang HEC Changjiang Pharmaceutical Co. Ltd., of Dongguan, China. Under the terms, TGBJ will receive $20 million for the 9 percent equity payable on or before March 31.