The upper molecular-weight limit for a small molecule is approximately 900 daltons, which allows for the possibility to rapidly diffuse across cell membranes so that it can reach intracellular sites of action.
[7] A variety of organisms including bacteria, fungi, and plants, produce small molecule secondary metabolites also known as natural products, which play a role in cell signaling, pigmentation and in defense against predation.
[11] Binding of ligand can be characterised using a variety of analytical techniques such as surface plasmon resonance, microscale thermophoresis[12] or dual polarisation interferometry to quantify the reaction affinities and kinetic properties and also any induced conformational changes.
Small-molecule anti-genomic therapeutics, or SMAT, refers to a biodefense technology that targets DNA signatures found in many biological warfare agents.
SMATs are new, broad-spectrum drugs that unify antibacterial, antiviral and anti-malarial activities into a single therapeutic that offers substantial cost benefits and logistic advantages for physicians and the military.