We then moved to establish the efficacy for this series of SSAs and their 1:1 enantiomeric mixtures towards cisplatin sensitive and resistant ovarian cancer cells. We have previously determined the GI50 (the concentration of a compound needed to inhibit 50 % of cellular growth) values for a series of sulfonate appended SSAs against cisplatin sensitive A2780 ovarian cancer cells. Here GI50 values between 45 ± 19 µM and 451 ± 38 µM were reported. As summarised in Figure , the GI50 values recorded for this series of carboxylate SSAs range from 87 ± 1 µM (7 and 9) to 231 ± 9 µM (5), showing the carboxylate based SSAs to report similar activities against this cancer cell line as the sulfonate SSAs. Here 9, and the 1:1 enantiomeric mixture of 7 and 9, demonstrated the greatest activity against A2780 ovarian cancer cells. This indicates anticancer activity to be influenced by the amino acid R-group present, chirality and SSA self-associative complexation processes, as previously observed when establishing the antimicrobial activity of these same agents. These observations are retained when investigating the activity of these same SSAs against the cisplatin resistant A2780 CisR cell line. Therefore, 9 shows the greatest anticancer activity against both cisplatin susceptible and resistant cancer cell lines, with an increased efficacy demonstrated when supplying 7 and 9 as a 1:1 enantiomeric mixture, as the 1:1 enantiomeric mixture of 7 and 9 was found to disproportionately increase activity of 9 against these cancer cells, as the effective concentration of 9 present is decreased by 50 %. This suggests, as observed when supplying chiral SSAs as antimicrobial agents, that this increase in efficacy could be due to alteration in, or stabilisation of SSA self-association events and/or resultant aggregate structure influencing molecular membrane permeation events.