Liu Zhijun
School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA.
Endocr Metab Immune Disord Drug Targets. 2008 Jun;8(2):112-21. doi: 10.2174/187153008784534358.
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.
植物是化学物质的储存库，这一事实推动了无数对生物活性化合物的多学科探索。作为植物学研究的第一步，整个目标就是找到具有特定生物活性的“有价值”植物。运用一些策略，在有限的时间和资源内最大限度地增加找到这些“有价值植物”的机会，这是合乎逻辑的。除了选择合适的植物进行筛选外，植物提取物的制备方式也会影响生物活性筛选结果。同一植物材料的提取物，由于制备方法不同，其化学成分可能有很大差异。由于植物提取物具有复杂的混合物性质，可能会观察到人为造成的活性。因此，通常需要进行确证性活性测试，以确保进入下一个费力的分离步骤。基于生物测定的分离方法在鉴定生物活性化合物方面可能是最有效的，因为在每个分离步骤中目标更明确，但植物化学分离方法适合于表征纯化的生物活性提取物。事实上，只要能提高效率，这两种方法可以交替使用。最后，已鉴定出的活性化合物的用途现在更广泛了。除了确定一种先导化合物以继续药物研发路径外，人们越来越关注支持将植物提取物用作植物药。在提取出先导化合物后，不再丢弃提取物，代表纯化提取物的天然类似物现在有机会成为治疗代谢综合征和其他疾病的新型疗法中的先导化合物。
