• 대한방사성의약품학회지
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• 제6권1호
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• pp.53-58
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• 2020

Pretargeting is a two-component strategy often used for tumor targeting to enhance the tumor-to-background ratio in cancer diagnosis as well as therapy. In the multistep strategy, the highly specific unlabeled monoclonal antibodies (mAbs) with the reactive site is allowed to get localized at tumor site first, and then small and fastclearing radiolabeled chelator with counter reactive site is administered which covalently attaches to mAbs via inverse electron demand Diels-Alder reaction (IEDDA). The catalyst-free IEDDA cycloaddition reaction between 1,2,4,5-tetrazines and strained alkene dienophiles aid with properties like selective bioconjugation, swift and high yielding bioorthogonal reactions are emergent in the development of radiopharmaceutical. Due to its fast pharmacokinetics, the in vivo formed radioimmunoconjugates can be imaged at earlier time points by short-lived radionuclides like ¹⁸F and ⁶⁸Ga; it can also reduce radiation damage to the normal cells. Ultimately, this review elucidates the updated status of pretargeting based on antibodies and IEDDA for tumor diagnosis (PET and SPECT) and therapy.

• 대한화학회지
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• 제42권1호
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• pp.69-77
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• 1998

4-styryl-2-azetidinone 7b의 bromoacetate에 의한 N-알킬화, 가오존분해, 산화, 말론산 에틸 마그네슘과의 축합 및 디아조 전달반응의 일련의 과정을 거처서 (3S,4S)-1-(t-butoxycarbonylmethyl)-3-[(S)-1-(t-butyldimethylsilyloxy)ethyl]-4-(2-diazo-2-ethoxycarbonyl-1-oxoethyl)-2-azetidinone(14)을 합성하였다. 또한 4-formyl-2-azetidinone 5b 의 Wittig 반응, ethoxycarbonylformonitrile oxide와의 1,3 이중극성 고리화 첨가반응, 촉매 수소화 및 디아조화 반응의 일련의 과정을 거쳐서 (3S,4S)-3-[(S)-1-(t-butyldimethylsilyloxy)ethyl]-4-(3-diazo-3-ethoxycarbonyl-1-hydroxypropyl)-2-azetidinone(21)을 합성하였다. 그러나 화합물 14 또는 21을 $Rh_2(OAc)_4$ 로 처리하여 1-hydroxycarbapenem 또는 1-hydroxycarbapenam으로 고리화하는 것을 성공하지 못하였다.

• 대한화학회지
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• 제26권3호
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• pp.172-178
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• 1982

4',5'-디히드로소랄렌(DHP)을 합성하여 상온 및 77K에서 이 화합물의 형광 양자수율은 0.08, 인광양자수율은 0.013, 형광수명은 0.95ns, 인광수명은 0.039s 임을 알았다. 이 결과로부터 형광수명은 5,7-디메톡시쿠마린보다 작은반면 소랄렌보다 크고 반면 인광수명은 DMC 보다 크고 소랄렌보다 작음을 알았다. 소랄렌 유도체들의 광독성을 분자적 차원에서 규명하고 DNA에의 광부가 반응을 알아내기 위하여 DHP와 TME의 광부가 반응을 연구하였다. 주 생성물은 TLC로 분석하고 Preparative TLC와 용매추출로 분리해냈다. 분리된 생성물의 구조는 질량분석기, UV, IR, NMR 그리고 원소분석결과에 의해 DHP와 TME외 광고리화첨가반응에 의한 생성물 임을 알았다. DHP는 형광의 자체소광 효과를 볼 수 없으며 TME, 에틸푸마레이트, 푸마로니트릴에 의해 형광이 효과적으로 소광된다. 광부가 반응의 양자수율과 소광실험에서 DHP의 광첨가반응은 단일상태와 삼중상태에서 다 일어나는 것으로 추측된다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권1호
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• pp.61-64
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• 2000

A series of 5-oxaproline peptide derivatives was synthesized and evaluated for its ability to inhibit the prolyl 4-hydroxylase in vitro. Structure-activity studies show that the 5-oxaproline sequences, prepared by the 1,3-dipolar cycloaddition of the C-methoxycarbonyl-N-mannosyl nitrone in the presence of the ethylene, are more active than the corresponding proline derivatives. Prolyl 4-hydroxylase belongs to a family of $Fe^{2+}-dependent$ dioxygenase, which catalyzes the formation of 4-hydroxyproline in collagens by the hydroxylation of proline residues in -Gly-Xaa-Pro-Gly- of procollagen chains. In this paper we discover the more selective N-Cbz-Gly-Phe-Pro-Gly-OEt $(K_m\;=\;520\;{\mu}M)$ sequences which are showed stronger binding than others in vitro. Therefore, we set out to investigate constrained tetrapeptide that was designed to mimic the proline structure of pep tides for the development of prolyl 4-hydroxylase inhibitor. From this result, we found that the most potent inhibitor is N-Dansyl-Gly-Phe-5-oxaPro-Gly-OEt $(K_i\;=\;1.6\;{\mu}M)$. This has prompted attempts to develop drugs which inhibit collagen synthesis. Prolyl 4-hydroxylase would seem a particularly suitable target for antifibrotic therapy.

• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.3001-3004
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• 2014

A series of hydroxyl-derivatized quaternized polymers were successfully synthesized by atom transfer radical polymerization (ATRP) and Cu(I)-catalyzed 1,3-dipolar cycloaddition of azide and alkynes (click chemistry), followed by quaternization reactions. ATRP was employed to synthesize poly(2-hydroxyethyl methacrylate) (PHEMA), followed by introduction of alkyne groups using pentynoic acid, leading to HEMA-Alkyne. 2-Azido-1-ethanol and 3-azido-1-propanol were combined with the HEMA-Alkyne backbone via click reaction, resulting in triazole-ring containing hydroxyl-derivatized polymers. Quaternization reactions with methyl iodide were conducted on the triazole ring of each polymer. Molecular weight, molecular weight distribution, and the degree of quaternization (DQ) were determined by gel permeation chromatography (GPC) and $^1H$ NMR spectroscopy. The average molecular weight ($M_n$) of the resulting polymers ranged from $5.9{\times}10^4$ to $1.05{\times}10^5g/mol$ depending on the molecular architecture. The molecular weight distribution was low ($M_w/M_n$ = 1.26-1.38). The transmission spectra of the 0.1 wt % aqueous solutions of the resulting quaternized polymers at 650 nm were measured as a function of temperature. Results showed that the upper critical solution temperature (UCST) could be finely controlled by the level of DQ.

• Bulletin of the Korean Chemical Society
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• 제8권2호
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• pp.96-101
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• 1987

2-Ethoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyran (1_a$), 2-n-butoxy-6-methoxy-5-cyano-3,4-dihydro-2H-pyr an (1b), 2-isobutoxy-6-methoxy-5-cyano-3,4-dihydro-2H-py ran ($1_c$), and 2-ethoxy-6-methoxy-3-methyl-5-cyano-3,4-dihydro -2H-pyran ($1_d$) were prepared by (4 + 2) cycloaddition reaction of methyl $\alpha$-cyanoacrylate with the corresponding alkyl vinyl ethers. Compounds $1_{a-d}$ were ring-open polymerized by cationic catalyst to obtain alternating head-to-head (H-H) copolymers. For comparison, head-to-tail (H-T) copolymer $3_a$ was also prepared by free radical copolymerization of the corresponding monomers. The H-H copolymer exhibited minor differences in its $1_H% NMR and IR spectra, but in the $^{13}C$ NMR spectra significant differences were observed between the H-H and H-T copolymers. Glass transition temperature ($T_g$) of H-H copolymer was higher than that of the H-T copolymer, but thermal decomposition temperature of the H-H copolymer was lower than that of the H-T copolymer. Compounds $1_a$, $a_b$, and $1_c$, copolymerized well with styrene by cationic catalyst, but compound 1d failed to copolymerize with styrene. All of the H-H and H-T copolymers were soluble in common solvents and the inherent viscosities were in the range 0.2-0.4 dl/g.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2193-2199
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• 2012

A series of novel polytriazoleimides were prepared from various aromatic dianhydrides and a new kind of 1,2,3-triazole-containing aromatic diamine synthesized by the Cu (I)-catalyzed 1,3-dipolar cycloaddition reaction in DMAc, and characterized by FT-IR, $^1H$-NMR, XRD, DSC and TGA techniques. The results show the polytriazoleimides are soluble in most of strong polar solvents and have inherent viscosity values of 0.51-0.62 dL/g(DMAc). The polytriazoleimide films exhibit a tensile strength of 62.3-104.5 MPa and an elongation at breakage of 4.0-8.1%, a glass transition temperature ($T_g$) of $257-275^{\circ}C$, a decomposition temperature (at 5% weight loss) of $350-401^{\circ}C$ in $N_2$ atmosphere, and a dielectric constant of 2.47-3.01 at 10 MHz, which depend on the structure of the polymers. The polytriazoleimides perform good resistance to acid and alkali solution.