Cisplatin
Cisplatin is a complex of platinum (ii) with chloride ion ligands and two ammonia ligands in a
square planar shape. The two chloride ions are next to each other making it cisplatin - cis
isomer. If they were opposite each other they would be trans and would have different biological
effects.
AntiCancer Drug
Cancer is caused when cells mutate and divide uncontrollably. In order for a cell to divide it
must replicate its DNA. The double helix therefore must unwind but cisplatin stops this
happening.
A nitrogen atom on the guanine base in DNA forms a coordinate bond with cisplatin's
platinum ion replacing one of the chloride ion ligands. This is a ligand replacement
reaction.
A second nitrogen atom from a nearby guanine molecule (on the same strand of DNA or
an opposite strand) can bond to platinum and replace the second chloride ion.
The cisplatin complex being bound to the DNA strands causes the strands to kink. This
means that the DNA cannot unwind properly, cannot be copied and the cell cannot
replicate properly.
The bond is covalent and permanent.
Cisplatin is a complex of platinum (ii) with chloride ion ligands and two ammonia ligands in a
square planar shape. The two chloride ions are next to each other making it cisplatin - cis
isomer. If they were opposite each other they would be trans and would have different biological
effects.
AntiCancer Drug
Cancer is caused when cells mutate and divide uncontrollably. In order for a cell to divide it
must replicate its DNA. The double helix therefore must unwind but cisplatin stops this
happening.
A nitrogen atom on the guanine base in DNA forms a coordinate bond with cisplatin's
platinum ion replacing one of the chloride ion ligands. This is a ligand replacement
reaction.
A second nitrogen atom from a nearby guanine molecule (on the same strand of DNA or
an opposite strand) can bond to platinum and replace the second chloride ion.
The cisplatin complex being bound to the DNA strands causes the strands to kink. This
means that the DNA cannot unwind properly, cannot be copied and the cell cannot
replicate properly.
The bond is covalent and permanent.
