Preparation of Botanical Samples for Biomedical Research

Zhijun      Liu

Abstract

Plants are chemical storehouses, a fact which has driven countless multidisciplinary quests for bioactive compounds. As the very first step of botanical research, the whole desire is to find “hit” plants with specific bioactivities. It is logical to use some strategies that can maximize the chances of finding these “hits” with limited time and resources. In addition to selecting the right plants for screening, how the plant extracts are prepared can also influence the bioactivity screening outcomes. An extract from the same plant material can be quite different in chemical composition having different preparations. Because of the complex mixture nature of plant extracts, it is possible artifact activities may be observed. Thus confirmatory activity tests are often necessary to warrant the next laborious isolation step. A bioassay directed isolation approach may be the most efficient in identifying the bioactive compounds because of the narrowed focus at each isolation step, but a phytochemistry isolation approach is appropriate to characterize a purified bioactive extract. In fact, these two approaches can be taken intermittently whenever efficiency can be improved. Finally, use of the identified active compounds is now broader. In addition to determining a lead compound to continue a drug development path, there is an increasing interest in support for the use of botanical extracts as botanical drugs. Instead of dropping the extract after extracting the lead compound, the natural analogues representing the purified extract now have a chance to become leading compounds in the pursuit of novel therapies for metabolic syndrome and other diseases.

Keywords: Ginkgo biloba, Supercritical Fluid Extraction, Pressurized liquid extraction, bioactivity, Plant screening