Bioactive materials screening

Screening of Bioactive Materials From Natnral Sources, J. Biomol. Screening,... 

The collection procedure itself is straightforward. After cataloguing and identification, 1-2 kg of the plant material is dried, or stored in alcohol and brought back to the lab. The plant material is crushed and extracted with various solvents (most plant-derived bioactive molecules are low molecular mass substances, soluble in organic solvents of varying polarity). After removal of the solvent, the extracts are screened for desirable biological activities (e.g. inhibition of microbial growth, selective toxicity towards various human cancer cell lines, etc.). 

The approach adopted to obtain an exploitable pure plant constituent involves interdisciplinary work in botany, pharmacognosy, pharmacology, chemistry, toxicology. The plant material is extracted by solvents of increasing polarity, the extracts are screened with different bioassays and submitted to fractionation with chromatographic techniques. This process is repeated until the isolation of a pure active constituent which is finally identified by spectroscopic methods (bioactivity-guided isolation)(Fig. 1). 

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