TABLE 1.

Susceptibilities of S. pneumoniae strains to boldine derivatives

Strains	Resistance patterna	MICb
		2	3	4	5	6	7	11	12	13	14	16	17	23
		μm
R6	S	500	500	>250	500	250	250	125	125	500	125	16	16	62
ATCC 6303	S	1000	1000	>250	500	>250	250	125	125	500	125	16	16	125
CipS8	S	500	500	>250	500	>250	125	125	125	500	125	16	16	62
CipS9	S	1000	1000	>250	1000	>250	250	125	125	500	125	16	16	125
CipR20	PTCEClSxTCip	1000	500	>250	250	>250	250	125	125	500	62	8	16	125
CipR16	PSxTCip	1000	1000	>250	500	>250	500	125	125	500	125	16	16	62
CipR8	PSxTCip	500	500	>250	500	>250	250	62	125	500	62	8	8	125
CipR42	PTEClCip	1000	1000	>250	500	>250	250	125	125	500	62	8	8	125
CipR45	TEClCip	500	500	>250	1000	>250	250	125	125	500	62	8	16	125
CipR68	Cip	500	500	>250	500	>250	250	125	125	500	62	8	8	125
CipR5	EClCip	500	500	>250	500	>250	250	125	125	500	62	16	16	62
CipR15	SxTCip	1000	1000	>250	500	>250	250	125	125	500	62	16	8	62

^a S, susceptible to all antibiotics tested; P, resistant to penicillin (MICs of 0.12–4 μg/ml); T, resistant to tetracycline (MICs ≥4 μg/ml); C, resistant to chloramphenicol (MIC ≥ 8 μg/ml); E, resistant to erythromycin (MIC ≥ 0.5 μg/ml); Cl, resistant to clindamycine (MIC ≥ 1 μg/ml); Cip, resistant to ciprofloxacin (MIC ≥ 4 μg/ml), SxT, resistant to cotrimoxazole (MIC ≥ 4 μg/ml for trimethoprim and MIC ≥ 76 μg/ml for sulfamethoxazole).

^b MICs for compounds B (boldine), 10, 19, 20, 21, and 22 were 1000 μm in all cases. The chemical structures of the compounds used are showed in supplemental Fig. S1.