Drug discovery Flashcards
What are the two classes of drugs?
Chemical and Biological
What are chemical drugs?
Range from inorganic salts to complex organic molecules. Referred to as small molecules as their molecular weight are less than 500. Wen discovered, referred to as new chemical entities.
What are biological drugs?
Known as large molecules. Usually proteins e.g. peptides or antibodies. When discovered, referred to as new biological entities.
What is the average cost of getting a drug to market?
£1.2 billion
What is a patent?
A patent is given right at the beginning to drug discovery by the government but only when the compound is novel (hasn’t been sighted anywhere in literature). The patent gives the inventor exclusive rights to their discovery and lasts up to 20 years
Where do novel small molecules come from? Name 5 ways they are discovered
1.) From nature
2.) From endogenous compounds
3.) Synthetic drugs, from screening
4.) ‘Me too’ drugs
5.) In silicio (computer aided) drug design
(can also utilize SE’s seen in other drugs e.g.sildenafil)
What is the main issue with using natural products as
drugs?
They are often very complex chemical structures and so can be difficult to synthesize in the lab and costly to manufacture
What is a semi-synthetic drug?
A drug that is derived from nature but has been modified synthetically in order to be more clinically useful e.g morphine undergoes acetylation to form diamorphine.
Why is nature a good source of molecules?
Nature is a source of chemical diversity = unlikely that a chemist would choose to design such a complex structure.
Natural ligands within the body make good lead compound but require analogue synthesis to make them more drug-like. Why?
A natural ligand might have an unfavourable duration of action, be metabolised or excreted too quickly or be chemically unstable e.g. salbutamol is an analogue of adrenaline.
Why do you have to be careful when changing the structure of natural ligands?
Analogues of natural ligands must retain their core structures in order to be able to bind to the biological target.
Name a synthetic drug
Ibuprofen (took 20 years and 650 synthetic analogues were screened)
Sulfonamides - antibiotics derived from azo dyes
Tamiflu (obatained using comptuer aided drud design)
What is a ‘me too’ drug?
A me too drug has a similar structure to an existing drug but is modified enough to make the compound novel but not enough to affect its activity (still interacts with the same receptor) (would not get a patent)
What is the name of the portion of a drug that is required for activity?
The pharmacophore
