Table 4.

Effect of 30-phosphate derivatives of betulin and reference compounds (betulin and cisplatin) on the viability of cells from four cancer cell lines studied.

	Compound	Human Cell Line/IC50 ± SD [µM]
		C-32	SNB-19	T47D	MDA-MB-231
30-phosphate derivatives	4	33.86 ± 1.59	5.01 ± 0.78	1.3 ± 0.13	14.48 ± 1.37
	5	43.46 ± 2.50	10.93 ± 1.33	1.04 ± 0.14	0.40 ± 0.02
	6a	---	---	9.50 ± 0.74	-
	7a	2.15 ± 0.22	0.91±0.09	2.61 ± 0.42	6.20 ± 0.22
	6b	NA	4.65 ± 0.51	NA	21.18 ± 1.24
	7b	0.80 ± 0.03	0.76 ± 0.14	15.40 ± 0.51	4.93 ± 0.44
	6c	NA	NA	NA	NA
	7c	11.90 ± 0.52	6.29 ± 0.12	NA	9.11 ± 0.39
	6d	31.46 ± 1.56	11.22 ± 0.28	NA	NA
	7d	6.90 ± 0.40	4.38 ± 0.04	9.47 ± 0.03	NA
	6e	11.43 ± 0.76	9.23 ± 0.57	NA	---
	7e	3.97 ± 0.86	1.59 ± 0.09	NA	---
29-phosphonate derivatives	10 *	8.80 ± 0.17	10.20 ± 0.69	10.71 ± 0.86	---
	11 *	0.60 ± 0.08	0.43 ± 0.14	0.70 ± 0.13	---
	12 *	7.70 ± 0.11	11.67 ± 0.44	14.94 ± 0.90	---
	13 *	6.99±1.07	---	12.2±0.84	---
	14 *	9.00 ± 0.53	---	NA	---
	Betulin	15.61 ± 1.11	9.93 ± 0.25	NA	7.76 ± 1.87
	Cisplatin	4.29 ± 0.65	5.29 ± 0.12	6.26 ± 1.24	5.47 ± 0.05

NA means IC₅₀ > 50 µM. * Phosphonate derivatives of betulin; synthesis and the results of the anticancer activity test were described previously [7].