. Author manuscript; available in PMC: 2010 Dec 21.

Published in final edited form as: Bioconjug Chem. 2009 Sep 28;20(10):1888–1898. doi: 10.1021/bc9001689

Table 1.

Structural analysis of PAMAM dendrimer conjugates by ¹H NMR and MALDI MS.

cmpd	PEG^a	NMR^b						MALDI
								DHB matrix				THAP matrix
		m	n	x	y^c	z	MW^d	M_n^e	M_w^f	PDI^g	z^h	M_n^e	M_w^f	PDI^g	z^h
7a	550	12.31	7.99	14.19	1	0	13021	10565	10974	1.04	0	n.d.ⁱ	n.d.ⁱ	n.d.ⁱ	0
7b	550	12.64	14.34	7.45	1	0	16758	13472	13922	1.03	0	13520	13930	1.03	0
7d	2000	43.89	4.61	19.32	1	0	17621	11844^j	12809^j	1.08^j	0	11875^j	12800^j	1.08^j	0
8c	750	15.40	11.81	0	1	0	16325	11620	12033	1.04	0	11238	11637	1.04	0
8d	2000	45.21	5.29	0	1	0	18470	n.d.ⁱ	n.d.ⁱ	n.d.ⁱ	0	9617^j	10444^j	1.09^j	0
9a	550	12.34	8.17	14.28	1	1.20	13721	10800	11127	1.03	0.32	10911	11262	1.03	N/A
9b	550	12.48	15.00	7.57	1	2.00	18026	14702	15457	1.05	3.19	15331	15831	1.03	3.95
9d	2000	43.25	4.74	19.30	1	1.14	18294	12843^j	13329^j	1.04^j	1.08	n.d.ⁱ	n.d.ⁱ	n.d.ⁱ	N/A
10c	750	15.75	11.32	0	1	14.05	22904	18575	19180	1.03	14.84	18848	19561	1.04	16.46
10d	2000	41.16	5.60	0	1	20.51	27982	21607	22824	1.06	N/A	22493	23518	1.05	27.15

M_n of the commercial PEG monomethyl ether (Aldrich) originally used to prepare compound 4.

Based on ¹H NMR integration determined in DMSO-d₆. m = number of PEG repeat unit, n = number of PEG, x = number of acetamide, y = number of AF₄₈₈, z = number of CGS21680 (see Scheme 1).

Based on the stoichiometry of addition.

Dendrimer conjugates were assumed to be made from the commercial PAMAM dendrimer with 32 peripheral amino groups and no structural defects. Counterions of sulfonate for AF₄₈₈ were assumed to be triethylammonium groups.

Number-average molar mass.

Weight-average molar mass.

Polydispersity index.

Based on MALDI MS results. No matrix adduct was considered for the estimation. ΔM_w between 9/10 and its precursor 7/8 was divided by the MW increase upon the covalent attachment of a CGS21680 ligand (481.5 Da) to the PAMAM amino group. Purification by SEC was assumed not to affect the MW distribution.

ⁱ

n.d. = not determined.

Mass range selected for the average MW calculations contained a part of the peak region corresponding to the half-size of each desired compound.