It is notable that the toxicity rate in the class of metal compounds was somewhat higher than that within the organic molecule group, i.e. 66% of active metal complexes also showed toxicity against mammalian cell lines and/or haemolysis, whereas this was the case for only 48% of organic molecules. This contrasts our analysis focused on antibacterial activity where both organic and metal compounds had similar toxicity rates. 32 Comparison of the distribution of all submitted compounds (Figure ) with the distribution of the active and non-toxic compounds (Figure ) re-enforces a trend that was observed previously, namely that the first-row transition metals seem to be vastly under-represented in the active and non-toxic group. Indeed, first-row transition metals make up 47% of submitted compounds, but only 21% of all active and non-toxic ones.