What are the different stages in drug discovery?

Answer 1

So I am not a drug chemist, but here is a general approach. Step 1: This plant relieves pain particularly the bark. Step 2: You take the bark to the lab MASH it up and do a solvent extraction. If you have no clue what you are looking for you will have to do aqueous and organic extractions. Step 3: Depending on how much money you have and what century your in you do one of two things, animal/ human testing on the extracts, or machine analysis. Step 4: Assuming your poor you evaporate off the aqueous extraction and eat the residue and see if that alleviates pain. If it does, you know the pain killer is in the aqueous extract, if it doesn't you know it is in the organic extract. Step 5: you do HPLC (High pressure liquid chromatography) or a silica gel column if your poor on whatever extract had the pain killer. This is a gradient ellution from polar to non-polar (or vice versa) with a detector that indicates the pressence of a chemical. You collect the "bands of chemicals" that come off the HPLC or silica gel column as a function of solution polarity. Step 5: you test all your bands of chemicals after evaporating off the solvent for pain killer properties on a patient. Hopefully the drug is in only one of your elutions. Step 6 you purify that single band that had the active drug by redisolving it and running it through a column. Step 7 you do TLC (thin layer chromotography throughout the experiment, but now to make sure you have only one compound in solution) Step 8 You submit the sample to IR, GC-mass spec, melting point, HNMR, and any other analytical fingerprinting tequnique to understand the structure of the chemical. Steo 9 You know the chemical structure now, hopefully it is not too different from a commercially availiable substance, maybe it has an extra R group, or hydroxy group, or NH2 or NH group. Now you get an organic book that has thousands of documented synthesis for adding on or taking off whatever functional group(s) you need. Step 10 You do the synthesis create a compound subject it to HNMR, IR, GC mass spec, melting point etc and hopefully it is the same structure of the plant based compound without any chiral enantiomers that give lousy side effects. Step 11 If you have the exact same compound you have created a synthetic plant based drug which can now be mass produced.

Answer 2

1: you will smell it 2: The people eating drugs will act mad