Sent_en: 2zh The drug called PA-457, which is derived from betulinic acid and comes from by-products from paper manufacturers, is being manufactured and developed by Maryland drug manufacturer Panacos Pharmaceuticals.
Sent_yy: 这种名为PA-457的药物是由桦木酸衍生而来，来自纸张制造商的副产品，由马里兰州药品制造商帕纳科斯制药公司生产和开发。