Complex sentence: Modern medicine, does, however, make use of many plant-derived compounds as the basis for evidence-tested pharmaceutical drugs, phytotherapy, and phytochemistry works to apply modern standards of effectiveness testing to herbs and medicines that are derived from natural sources.
Split into simpler sentences: Modern medicine, does, however, make use of many plant-derived compounds as the basis for evidence-tested pharmaceutical drugs. Phytotherapy, and phytochemistry work to apply modern standards of effectiveness testing to herbs and medicines that are derived from natural sources.