Table III.

Inhibition of bacterial isolates to shikonin, shikonin derivatives, and whole-root chloroform extractions

Bacterial Isolate	Standards							Root Culture Extractiona
	Shikonin	DS	IBS	DMAS	IVS	MBS	AS	M	M-9	IVS/MBS	AS	HIVS
	mm
B. subtilis	2.0	1.0	0.5	0.0	0.5	1.0	3.5	2.5	4.0	2.0	4.0	4.0
B. thuringiensis	2.0	0.5	0.0	0.0	0.1	0.1	2.0	2.5	ndb	0.0	2.0	3.0
C. michigenensis subsp. nebraskensis	4.0	4.0	1.0	1.0	0.5	1.5	4.0	4.0	2.0	1.0	3.0	4.0
A. radiobacter	3.0	1.0	0.5	0.0	0.0	1.0	3.0	3.0	4.0	1.0	2.0	2.0
A. rhizogenes	1.0	0.1	0.1	0.1	0.1	0.5	1.5	1.5	2.0	1.0	1.5	2.0
A. tumefaciens	0.5	0.0	0.1	2.0	0.1	0.1	1.5	3.0	3.0	2.0	2.0	3.0
B. cepacea	2.0	2.0	2.0	0.0	0.5	0.5	2.0	3.0	4.0	0.5	2.0	3.0
E. coli	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
E. amylovora	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	2.0	0.0	0.0	0.0
E. carotovora	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	1.0	0.0	0.0	0.0
E. herbicola	1.5	0.5	0.1	0.1	0.1	0.5	2.0	2.0	2.0	0.5	2.0	3.0
P. aureofaciens	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	nd	nd	nd	nd
P. fluorescens	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	nd	nd	nd	nd
P. syringae	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
P. syringae pv phaseolicola	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
R. solanacearum	1.0	1.0	0.1	0.1	0.1	0.5	3.0	3.0	2.0	0.5	2.0	2.0
S. marsecens	1.0	0.1	0.1	0.0	0.1	0.1	3	2.0	nd	nd	nd	nd
X. campestris pv pelargonii	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Data are presented as the size of the zone of inhibition. In all cases, sd was less than 0.289.

^aChloroform extraction of pigments from roots grown in liquid culture. Separation of components by TLC as described in Methods. 

^bnd, Not determined.