Hydrazinonicotinamide (HYNIC) forms stable coordination complexes with Tc-99m when reacted with Tc(V)oxo species such as Tc-mannitol or other Tc-polyhydric complexes. However, radio-HPLC of [Tc-For-MLFK-HYNIC] labeled via Tc-polyhydric ligands demonstrated multiple radiochemical species each with unique biodistribution patterns. This is likely due to the fact that Tc can bind to the hydrazino moiety, as well as polyhydric ligands, in a variety of coordination geometries. Tridentate ligands, such as bis(mercaptoethyl)methylamine (NS2), may constrain the possible coordination geometries and improve overall stability. To investigate this, we synthesized NS2, converted the [Tc-mannitol-For-MLFK-HYNIC] to the corresponding NS2-containing complex [Tc-NS2-For-MLFK-HYNIC], and compared its infection imaging and biodistribution properties with [Tc-mannitol-For-MLFK-HYNIC]. Conversion to the NS2 complex was confirmed by HPLC which showed a single unique hydrophobic species with retention time greater than the [Tc-mannitol-For-MLFK-HYNIC] complex. Imaging experiments with both preparations were performed in rabbits with E. coli infections in the left thigh. Tissue radioactivity measurements demonstrated that compared to Tc-mannitol-peptide, accumulation of Tc-NS2-peptide was lower in blood, heart, and normal muscle and higher in spleen, infected muscle, and pus (p < 0.01). These results indicate that the Tc-NS2-peptide complex is chemically more homogeneous and exhibits improved infection localization and biodistribution properties. In an effort to model the interactions of the metal-HYNIC core with NS2 and related ligand types, the reactions of [ReCl3(NNC5H4NH)(NHNC5H4N)] and [99TcCl3(NNC5H4NH)(NHNC5H4N)], effective structural analogues for the {M(NNC5H4NHx)2} core, with NS2, C5H3N-2,6-(CH2SH)2, O(CH2CH2SH)2, and S(CH2CH2SH)2 were investigated and the compounds [M{CH3N(CH2CH2S)2}(NNC5H4N)(NHNC5H4N] (M = 99Tc (5a), Re (5b)), [Re{C5H3N-2,6-(CH2S)2}(NNC5H4N)(NHNC5H4N)]·CH2Cl2·0.5MeOH (7), [Re{SCH2CH2)2O} (NNC5H4N)(NHNC5H4N)] (8), and [Re{(SCH2CH2)2S}(NNC5H4NH)(NHNC5H4N)]Cl (9) were isolated. Similarly, the reaction of [ReCl3(NNC5H4NH)(NHNC5H4N)] with the bidentate ligands pyridine-2-methanethiol and 3-(trimethlysilyl)pyridine-2-thiol led to the isolation of [ReCl(C5H4N-2-CH2S) (NNC5H4N)(NHNC5H4N)] (10) and [Re(2-SC5H3N-3-SiMe3)2 (NNC5H4N)(NHNC5H4N)] (11), respectively, while reaction with N-methylimidazole-2-thiol yielded the binuclear complex [Re(OH)Cl(SC3H2N2CH3)2(NNC5H4N)2 (NHNC5H4N)2] (12). The analogous metal-(HYNIC-OH) precursor, [ReCl3{NNC5H3NH(CO2R)} {NHNC5H3N(CO2R)}] (R = H, 13a; R = CH3, 13b) has been prepared and coupled to lysine to provide [RCl3{NNC5H3NH(CONHCH2CH2CH2CH2CH(NH2)CO2H)} {NHNC5H3NH(CONHCH2CH2CH2CH2CH(NH2)CO2H)}]·2HCl (14·2HCl), while the reaction of the methyl ester 13b with 2-mercaptopyridine yields [Re(2-SC5H4N)2{NNC5H3N(CO2Me)}{NHNC5H3N(CO2Me)}] (15). While the chemical studies confirm the robustness of the M-HYNIC core (M = Tc, Re) and its persistence in ligand substitution reactions at adjacent coordination sites of the metal, the isolation of oligomeric structures and the insolubility of the peptide conjugates of 13, 14, and 15 underscore the difficulty of characterizing these materials on the macroscopic scale, an observation relevant to the persistent concerns with reagent purity and identity on the tracer level.
To observe the expression and distribution of TGF-β1 in periodontal tissue under intervention of Strontium ranelate and Qianggu capsule during orthodontic tooth movement in rats, and explore the efficacy of the 2 drugs.Seventy male SD rats of 3 months old were selected in the study, and randomly divided into control group, model control group, Strontium ranelate group, Qianggu capsule group, each group had 15 animals. Retinoic acid was given by gavage to animals in the control group, Strontium ranelate group, Qianggu capsule group for 2 weeks, and bone density was detected to determine successful establishment of osteoporosis model. All rats were installed orthodontic device, and were sacrificed at 7 days, 14 days and 21 days, respectively. The tissue blocks of the first maxillary molar and adjacent alveolar bone were taken for H-E staining, immunohistochemical staining and semi-quantitative analysis was used to detect TGF-β1 expression in periodontal tissues. The data were statistically analyzed by SPSS 17.0 software package.TGF- beta 1 expression was significantly increased in Strontium ranelate group and Qianggu capsule group compared with control group (P<0.05); TGF- beta 1 expression in Strontium ranelate group was significantly stronger than that of Qianggu capsule group (P<0.05).Strontium ranelate and Qianggu capsule could enhance the expression of TGF- beta 1 and promote bone metabolism in osteoporosis rats, which is helpful to the movement of healthy teeth; the effect of Strontium ranelate is stronger than Qianggu capsule.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
The key intermediate of monocyclic beta-lactams, N-benzyloxycarbonyl-3 S-amino-2-oxoazetidine(Ⅲ),was synthesized from L-( + )-2,3-diaminopropanoie acid(Ⅰ) by Ph_3P—(PyS)_2—CH_3CN system and N-benzyloxycarbonylation. Ⅰ was prepared from L(+)-aspartic acid by Schmidt rearrangement.Three derivatives(Ⅷa～c) of this monocyclic beta-lactam were prepared and their biological activities evaluated.
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