Natural products are a major resource for the pharmaceutical industry.Historically, drug discovery and development from natural products has been a time-and resource-intensive process.It is one of the major tasks for phytochemists to get the target active compounds more efficiently.The ability to rapidly identify known or undesirable compounds in natural products extracts is a critical step in an efficiently run natural products discovery program.This process, commonly called dereplication, is important to prevent the unnecessary use of resources and time.To solve this problem, one of the strategy is to perform on-line structure elucidation for the crude extract on the early stage.