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[00196] In particular, the wmTC chelating moiety (symbolized as EC20)(-DAP-Asp-Cys) was first prepared according to a reported procedure36. Briefly, acid-sensitive Wang resin loaded with 0.106 mmol of H-carbonyl-trityl-L-cysteine (H-L-Cys (Trt)-OH) was reacted first with Fmoc- Asp(Otbu)-OH (0.265mmol), HATU (0.265 mmol) and diisopropylethylamine (1.06mmol) followed by addition of beta-L-diaminopropionic acid (0.265mmol),HATU (0.265 mmol) and diisopropylethylamine (1.06mmol) to yield the 9mTc chelating moiety. The chelator was then conjugated to Z-360 via a variety of spacers that were selected for both their abilities to render the final conjugate water soluble and to reduce nonspecific binding to receptor negative cells. The monomeric components of these spacers were derived from protected amino acids and a peptidosaccharide (PS) construct described by others. All conjugation reactions were performed under argon atmosphere. acid-sensitive Wang resin loaded with 0.106 mmol of fluorenylmethoxy carbonyl-trityl-L-cysteine (Fmoc-L-Cys(Trt)-OH) was reacted first with HATU (0.265 mmol), followed by sequential addition of the desired protected monomer (0.265 mmol). Fmoc protecting groups were removed after each coupling step using standard conditions (20% piperidine in dimethyl formamide). Removal of the partially deprotected conjugate from the polymeric support was finally accomplished by treatment with a cocktail solution comprising of 92.5% trifluoroacetic acid (TFA), 2.5% 1,2-ethanedithiol, 2.5% triisopropylsilane, and 2.5% deionized water. This reaction also resulted in simultaneous removal of all t-butyl (t-Bu), t- butoxycarbonyl (t-Boc) and trityl protecting groups.; Synthesis ofZ-360-Linker B [00221] Z-360 was first attached to a linker using the previously described procedure for the radio-imaging agent above to produce Z-360-linker B (Scheme 6 below). Scheme 6 Scheme 6: Synthesis of Z-360-linker B. Reagents and conditions: (a) (i) 20% piperidine/DMF, rt, 10 min; (ii) 3,4,5, 6-Di-isopropylidene-l-amino-deoxy(Fmoc-Glu-OH)-D-glucitol, HATU, DIPEA, 4 h; (b) (i) 20% piperidine/DMF, rt, 10 min; (ii) Fmoc-Glu(OtBu)-OH, HATU, DIPEA, 4 h; (c) (i) 20% piperidine/DMF, rt, 10 min; (ii)3,4,5,6-Di-isopropylidene-l-amino-deoxy(Fmoc- Glu-OH)-D-glucitol, HATU, DIPEA, 4 h; (d) (i) 20% piperidine/DMF, rt, 10 min; (ii) Fmoc- Glu(OtBu)-OH, HATU, DIPEA, 4 h; (e)(i) 20% piperidine/DMF, rt, 10 min; (ii) Fmoc-8-amino- octanoic , HATU, DIPEA, 4 h; (f) (i) 20% piperidine/DMF, rt, 10 min; Z-360, HATU, DIPEA, Overnight; i) TFA/H20/TIPS/EDT (92.5:2.5:2.5:2.5). |