Table 1.

The fluorophore-substituted compounds photophysical properties and abilities to inhibit pili- and curli-dependent biofilm formation.

ID	R1 (C8)	R2 (C7)	X	EC50[a] Pili [μM]	EC50[a] Curli [μM]	λabs[b,c] [nm]	λfl[b,d] [nm]	Quantum Yield[b] ΦF [%] (λex nm)
11 a			-S-	>200	NA[e]	328	394	5 (330)[f]
11 b			-S-	>200	NA[e]	330	420	1 (330)[f]
11 c			-S-	>200	NA[e]	328	396	0.7 (330)[f]
11 d			-S-	>200	NA[e]	328	413	0.4 (330)[f]
16 a			-S-	65	175	329	430	0.6 (355)[f]
16 b			-S-	156	NA[e]	327	393	0.5 (330)[f]
16 c			-S-	18	25	393	474	15 (390)[g]
16 d			-S-	12	NA[e]	392	484	6 (330)[f]
23			-S-	5	17	396	478	11 (346)[f]
28			-S-	4	14	506	524	10 (470)[h]
31			-S-	14	12	502	514	67 (470)[h]
34			-S-	10	24	498	509	11 (480)[h]
37			-O-	13	14	497	531	27 (480)[h]
38			-S(O)-	29	40	498	516	71 (480)[h]
3			-S-	17	38	–	–	–

[a] Estimated from 16–32 data points on every concentration. [b] All substances were dissolved in DMSO and subsequently diluted in phosphate buffer at pH 7.0. The samples DMSO concentrations never exceed 5 wt %. The sample concentrations in the DMSO stock solutions are adjusted so that the final samples never have a peak absorbance higher than 0.1. [c] Wavelengths of the peak absorption. [d] The peak fluorescence. [e] Not active. [f] Reference: POPOP in MeOH. [g] Reference: Perylene in cyclohexane. [h] Reference: Rhodamine 6G in water.