L41-purification techniques

what are the 4 main sources of drugs

• nature

• semi-synthetic

• fully synthetic

• biochemically engineered

describe nature as a source of drugs

• compounds found in nature are called natural products

• e.g. morphine from opium poppy

• Taxol, penicillin, insulin

• NP have a purpose or function so every natural product is biochemically active

describe semi-synthetic products as a source of drugs

• natural products that are modified to improve physiochemical properties

• e.g. heroin( diamorphine ), aspirin, Taxol

• NP aren’t designed for human use

describe fully synthetic products as a source of drugs

• theses are drugs that are entirely made in the lab from basic building blocks

• these are designed as drugs and the majority of modern drugs.

• e.g. paracetamol, Viagra, aspirin

describe bioengineered products as a drug source

• these include proteins, monoclonal antibodies, gene therapies

list 5 purification methods

• recrystallisation

• filtration

• distillation

• separating funnels techniques

• chromatography

describe recrystallisation

• a mixture is all dissolved in hot solvent

• the mixture is allowed to cool down- this causes the impurities to stay in the solution and the desired compounds crystallise

• then the need to be separated

describe filtration as a separation techniques

• after doing recrystallisation to obtain the desired compounds as crystals and the impurities that remain in the solution the mixture is filtered to obtain the crytals

describe distillation as a purification technique

• its based on compounds having different boiling points

• its good for volatile compounds

describe separating funnel techniques as a purification method

• organic solvents are either non-halogenated or halogenated- depends on density

• non halogenated < aqueous < halogenated

• non halogenated solvent are the least dense whilst halogenated are most dense

describe chromatography as a purification technique

• the separation of a mixture by passing through a medium where the components move at different rates

• in a mixture of different compounds different compounds will move across the stationary phase at different rates due to different interactions

what is TLC, HPLC,

TLC- thin layer chromatography

HPLC- high performance liquid chromatography

explain the prcess of TLC

• its mostly used to follow reactions

• then uv light is used to visualise the plate

• you can also chemically stain the plate

explain HPLC

• high performance liquid chromatography

• used to analyse and purify compounds

• enantiomers can be separated by using a chiral stationary phase as the different enantiomers will react differently with the plate