TABLE 2.

Major components of Aroclor 1260 and their dechlorination by CBDB1

Congenera	DB1 Pk	IUPAC no.	mol% of total PCBs				% Decrease	Inferred pathway and ultimate productsd
			Aroclor 1260b	Dechlor. Aroclor 1260c	SD	Change
245-245-CB*	75	153	11.66	1.12	0.48	-10.54	90	245-25-CB → 25-25-CB
2345-245-CB*	102	180	9.71	2.61	1.07	-7.10	73	235-245-CB → 235-25-CB
236-245-CB*	69	149	9.47	8.41	0.48	-1.06	11	236-25-CB
234-245-CB*	82	138	8.53	1.49	0.25	-7.04	83	234-25-CB → 24-25-CB + 23-25-CB
2356-245-CB	88	187	5.50	5.61	0.29	0.11
2345-234-CB	106	170	3.97	0.88	0.40	-3.09	78	235-234-CB → 235-24-CB + 235-23-CB
245-25-CB	53	101	3.79	0.70	0.04	-3.09	82	25-25-CB
2345-236-CB	93	174	3.77	0.79	0.33	-2.98	79	235-236-CB
234-236-CB	74	132	3.39	1.52	0.22	-1.87	55	24-236-CB + 23-236-CB
2356-34-CB	82	163	3.09	3.09	0.00	0.00
2356-25-CB	64	151	3.00	3.38	0.13	0.38
2356-234-CB	94	177	2.73	2.33	0.15	-0.40	15	2356-24-CB
2346-245-CB	90	183	2.59	1.15	0.25	-1.44	56	246-245-CB → 246-25-CB
236-25-CB	48B	95	2.44	3.44	0.13	1.00
236-34-CB	61	110	1.69	2.50	0.17	0.81
235-236-CB	65	135	1.65	5.87	0.37	2.53
236-236-CB	60	136	1.47	1.62	0.03	0.15
235-245-CB	73	146	1.47	1.08	0.35	-0.39	27	235-25-CB
2345-2345-CB	115	194	1.37	0.83	0.19	-0.54	39	235-2345-CB → 235-235-CB
2345-25-CB	77	141	1.36	0.00	0.00	-1.36	100	235-25-CB
2345-2356-CB	109	199	1.21	0.81	0.16	-0.40	33	235-2356-CB
2346-234-CB	95	171	1.19	0.50	0.11	-0.69	58	246-234-CB→ 246-24-CB + 246-23-CB
2346-25-CB	66	144	1.10	0.00	0.00	-1.10	100	246-25-CB

^aThe congeners marked with asterisks are the four congeners that accumulate to the highest levels in humans (37).

^bData are the means for two uninoculated controls.

^cDechlor., dechlorinated. Data are the means for the three CBDB1 cultures that showed the most extensive dechlorination.

^dWhen there is more than one pathway, only the dominant pathway is shown because of space limitations.