Table 2. Pleuromutilins with Other Boron Heterocycles Linked via C(14).

ID	P	Q–R	R8	Wolbachia infected C6/36 cells (wAlb) EC50 (nM)	Wolbachia infected LDW1 cells (wMel) EC50 (nM)
40	CH3SO2N	N=CH	H	9	0.8
41	CH3N	N=CH	H	14.8	1.5
42	CH3C(=O)N	N=CH	H	4	0.2
43	Boc-N	N=CH	H	0.7	0.2
44	HN	N=CH	H	3.5	2.7
45	CH3OC(=O)N	N=CH	H	1.5	0.3
46	O	N=CH	H	14.2	5.1
47	CH3SO2N	N=CH	8-F	240	6.3
48	CH3N	N=CH	8-F	172	11
49	CH3C(=O)N	N=CH	8-F	107	NTa
50	CH3OC(=O)N	N=CH	8-F	164	1.3
51	O	N=CH	8-F	329	27
52	CH3C(=O)N	N=CH	8-CH3	26.1	NT
53	O	CH2CH2	H	>1000	NT

^aNT = not tested.