• 제목/요약/키워드: ligand

검색결과 2,344건 처리시간 0.029초

Involvement of Bcl-2 Family and Caspases Cascade in Sodium Fluoride-Induced Apoptosis of Human Gingival Fibroblasts

  • Jung, Ji-Yeon;Park, Jae-Hong;Jeong, Yeon-Jin;Yang, Kyu-Ho;Choi, Nam-Ki;Kim, Sun-Hun;Kim, Won-Jae
    • The Korean Journal of Physiology and Pharmacology
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    • 제10권5호
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    • pp.289-295
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    • 2006
  • Sodium fluoride (NaF) has been shown to be cytotoxic and elicit inflammatory response in human. However, the cellular mechanisms underlying NaF-induced cytotoxicity in periodontal tissues have not yet been elucidated. This study is aimed to investigate the mechanisms of NaF-induced apoptosis in human gingival fibroblast (HGF). NaF decreased the cell viability of HGF in a dose- and time-dependent manner. NaF gave rise to apoptotic morphological changes including cell shrinkage, chromatin condensation, and DNA fragmentation. However, NaF did not affect the production of ROS. In addition, NaF augumented cytochrome c release from mitochondria into the cytosol, and enhanced caspase -9 and -3 activities., cleavage (85 kDa fragments) of poly (ADP-ribose) polymerase (PARP) and upregulation of voltage-dependent anion channel (VDAC) 1. These results demonstrated that NaF-induced apoptosis in HGF may be mediated with mitochondria. Furthermore, NaF elevated caspase-8 activity and upregulated Fas-ligand (Fas-L), suggesting involvement of death receptor mediated pathway in NaF-induced apoptosis. Expression of Bcl-2, an anti-apoptotic Bcl-2 family, was downregulated, whereas expression of Bax, a pro-apoptotic Bcl-2 family, was not affected in NaF-treated HGF. These results suggest that NaF induces apoptosis in HGF through both mitochondria- and death receptor-mediated pathway mediated by Bcl-2 family.

Generation of $CD2^+CD8^+$ NK Cells from c-$Kit^+$ Bone Marrow Cells in Porcine

  • Lim, Kyu-Hee;Han, Ji-Hui;Roh, Yoon-Seok;Kim, Bum-Seok;Kwon, Jung-Kee;You, Myoung-Jo;Han, Ho-Jae;Ejaz, Sohail;Kang, Chang-Won;Kim, Jong-Hoon
    • The Korean Journal of Physiology and Pharmacology
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    • 제16권3호
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    • pp.167-174
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    • 2012
  • Natural killer (NK) cells provide one of the initial barriers of cellular host defense against pathogens, in particular intracellular pathogens. Because bone marrow-derived hematopoietic stem cells (HSCs), lymphoid protenitors, can give rise to NK cells, NK ontogeny has been considered to be exclusively lymphoid. Here, we show that porcine c-$kit^+$ bone marrow cells (c-$kit^+$ BM cells) develop into NK cells in vitro in the presence of various cytokines [interleukin (IL)-2, IL-7, IL-15, IL-21, stem cell factor (SCF), and fms-like tyrosine kinase-3 ligand (FLT3L)]. Adding hydrocortisone (HDC) and stromal cells greatly increases the frequency of c-$kit^+$ BM cells that give rise to $CD2^+CD8^+$ NK cells. Also, intracellular levels of perforin, granzyme B, and NKG2D were determined by RT-PCR and western blotting analysis. It was found that of perforin, granzyme B, and NKG2D levels significantly were increased in cytokine-stimulated c-$kit^+$ BM cells than those of controls. And, we compared the ability of the cytotoxicity of $CD2^+CD8^+$ NK cells differentiated by cytokines from c-$kit^+$ BM cells against K562 target cells for 28 days. Cytokines-induced NK cells as effector cells were incubated with K562 cells as target in a ratio of 100 : 1 for 4 h once a week. In results, $CD2^+CD8^+$ NK cells induced by cytokines and stromal cells showed a significantly increased cytotoxicity 21 days later. Whereas, our results indicated that c-$kit^+$ BM cells not pretreated with cytokines have lower levels of cytotoxicity. Taken together, this study suggests that cytokines-induced NK cells from porcine c-$kit^+$ BM cells may be used as adoptive transfer therapy if the known obstacles to xenografting (e.g. immune and non-immune problems) were overcome in the future.

미세먼지 유도 기도염증에 대한 배암차즈기 추출물의 호흡기 보호 효과 (Respiratory Protective Effect of Salvia plebeia R. Br. Extracts against Ambient Particulate Matter-induced Airway Inflammation)

  • 송형우;지건영;김복규;양원경;한창균;신한재;박양춘;황지숙;강형식;김승형
    • 한국약용작물학회지
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    • 제25권5호
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    • pp.269-281
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    • 2017
  • Background: Small particles increase airway inflammation upon reaching the alveoli. Here, we investigated the protective or therapeutic effects of Salvia plebeia R. Br. (SP_R) extracts on airway inflammation. Methods and Results: To investigate the anti-inflammatory activity of SP_R extracts, we measured their inhibitory effect on the production of reactive oxygen species (ROS) expression of inflammatory mediators, and immune cell infiltration in MH-S alveolar macrophage cells and in the ambient particulate matter (APM)-exposed airway inflammation mice model. The SP_R extracts inhibited the production of ROS and expression of IL-4, IL-10, IL-15, and IL-17A mRNA in APM-stimulated MH-S cells. Oral administration of SP_R extracts suppressed APM-induced inflammatory symptoms, such as high alveolar wall thickness, excess collagen fibers, decreased mRNA expression of chemokines (Ccr9, Ccl5, Ccr3), inflammatory cytokines (IL-15, TNF-${\alpha}$), and IL-4 Th2 cytokine in the lung. The SP_R extracts also inhibited ROS production, granulocyte ($CD11b^+Gr-1^+$) infiltration, IL-17A, TNF-${\alpha}$, macrophage inflammatory protein (Mip-2), and chemokine (C-X-C motif) ligand 1 (Cxcl-1) production in the airway. The specific compounds in the SR-R extracts that mediate the anti-inflammatory effects were identified. Conclusions: In this study, SP_R extracts effectively inhibited airway inflammatory responses, such as ROS production and granulocyte infiltration into the airway, by regulating the expression of chemokines and inflammatory cytokines.

MOVCD에 있어서 구리(l)전구체들의 열적 안정성이 증착에 미치는 영향 (The Effect of Thermal Stability of Cu(I) Precursors on the Deposition in the Metal Organic Chemical Vapor Deposition)

  • 박만영;이시우
    • 한국재료학회지
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    • 제8권4호
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    • pp.345-353
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    • 1998
  • 음이온 리간드로 hfac이 배위된 세 가지 종류의 구리(l) 전구체들의 열적 안정성, 기상분해 특성, 증착 특성 등을 연구하였다. $^{1}$H-NMR결과로부터 (hfac) Cu(VTMS) (hfac=hexafluoroacetylacetonate, VTMS=vinyltrimethylsilane)와 (hfac)Cu(VTMS) (VTMOS=vinyltrimethoxysilane)는 열적으로 안정한 화합물이라는 것을 확인할 수 있었으며, (hfac)Cu(ATMS)(STMS=allyltrimethylsilane)는 다른 전구체에 비해 열적으로 불안정한 화합물이라는 것을 확인할 수 있었다. In-situ FT-IR을 이용하여 기상 분해 특성을 연구한 결과 (hfac)Cu(VTMS)의 경우 $150^{\circ}C$부근에서 $Cu(hfac)_{2}$, $240^{\circ}C$부근에서 free한 상태의 hfac의 생성을 확인할 수 있었으며, 이러한 특성이 박막의 증착 속도와 물성에 미치는 영향을 확인하였다. 그리고 이들 전구체들의 증착 특성을 연구하였으며 (hfac)Cu(ATMS)의 경우 아르곤 운반 기체하에서 기판 온도가 $60^{\circ}C$일 때 구리 박막이 증착이 시작되는 것을 관찰할 수 있었는데, 이러한 낮은 증착 온도는 상대적으로 약한 구리와 ATMS의 결합력에 의한 것으로 생각된다.

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Expression of peroxisome proliferator activated receptor gamma in the neuronal cells and modulation of their differentiation by PPAR gamma agonists

  • Hong, Jin-Tae
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2002년도 Molecular and Cellular Response to Toxic Substances
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    • pp.14-40
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    • 2002
  • 15-Deoxy- Δ$\^$12,14/-prostaglandin J$_2$ (15-deoxy-PGJ$_2$), a naturally occurring ligand activates the peroxisome proliferator-activated receptor-${\gamma}$ (PPAR-${\gamma}$). Activation of PPAR-y has been found to induce cell differentiation such as adipose cell and macrophage. Here it was investigated whether 15-deoxy-PGJ$_2$ has neuronal cell differentiation and possible underlying molecular mechanisms. Dopaminergic differentiating PC 12 cells treated with 15-deoxy-PGJ$_2$ (0.2 to 1.6 ${\mu}$M) alone showed measurable neurite extension and expression of neurofilament, markers of cell differentiation. However much greater extent of neurite extension and expression of neurofilament was observed in the presence of NGF (50 ng/$m\ell$). In parallel with its increasing effect on the neurite extension and expression of neurofilament, 15-deoxy-PGJ$_2$ enhanced NGF-induced p38 MAP kinase expression and its phosphorylation in addition to the activation of transcription factor AP-1 in a dose dependent manner. Moreover, pretreatment of SD 203580, a specific inhibitor of p38 MAP kinase inhibited the promoting effect of 15-deoxy-PGJ$_2$ (0.8 ${\mu}$M) on NGF-induced neurite extension. This inhibition correlated well with the ability of SB203580 to inhibit the enhancing effect of 15-deoxy-PGJ$_2$ on the expression of p38 MAP kinase and activation of AP-1. The promoting ability of 15-deoxy-PGJ$_2$ did not occur through PPAR-${\gamma}$, as synthetic PPAR-${\gamma}$ agonist and antagonist did not change the neurite promoting effect of 15-deoxy-PGJ$_2$. In addition, contrast to other cells (embryonic midbrain and SK-N-MC cells), PPAR-${\gamma}$ was not expressed in PC-12 cells. Other structure related prostaglandins, PGD$_2$ and PGE$_2$ acting via a cell surface G-protein-coupled receptor (GPCR) did not increase basal or NGF-induced neurite extension. Moreover, GPCR (EP and DP receptor) antagonists did not alter the promoting effect of 15-deoxy-PGJ$_2$ on neurite extension and activation of p38 MAP kinase, suggesting that the promoting effect of 15-deoxy-PGJ$_2$ may not be mediated GPCR. These data demonstrate that activation of p38 MAP kinase in conjunction with AP-1 signal pathway may be important in the promoting activity of 15-deoxy-PGJ$_2$ on the differentiation of PC12 cells.

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울금의 주요 성분인 커큐민과 나노 마이셀링 기법 적용 염화 커큐민의 트랜스타이레틴 활성 부위에 대한 결합 친화도 비교분석 (Molecular Docking Affinity Comparison of Curcumin and Nano-micelled Curcumin with Natural Sea Salt on Transthyretin)

  • 김동찬;송표
    • 생명과학회지
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    • 제26권2호
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    • pp.253-258
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    • 2016
  • 본 연구에서는 울금의 주요 성분인 커큐민과 나노 마이셀링 기법을 적용한 신규 조성물인 염화 커큐민(NMC)의 트랜스타이레틴(TTR) 단백질 활성 부위에 대한 in silico 분자 결합 친화도를 비교 분석하였다. 우선 NMC신규 조성물의 결정학적 구조를 광학 및 전자현미경을 활용하여 관찰하였을 때, 나노 마이셀링 적용 NMC 결정은 일반 천일염에 비하여 색상 및 질감이 전체적으로 균일화 되었고, 천일염과 NMC성분이 강하게 일체화되어 기간이 상당히 경과 되더라도 쉽게 분리가 되지 않는 고기능성 안전성 구조물이 형성되었다. TTR단백질의 3차원 구조 활성 부위에 대한 in silico 분자 결합 친화도는 NMC가 일반 커큐민에 비하여 상대적으로 높은 결합 친화도를 나타나었고, pharmacophore 모델링 분석에서도 NMC가 일반 커큐민에 비하여 TTR 활성 부위에서 현저하게 pharmacophore 각도의 차이가 나타났었으며 패턴 또한 밀집된 특징을 나타내었다. 결론적으로, 나노 마이셀링 적용 NMC가 일반 커큐민에 비하여 상대적으로 우수하게 TTR 단백질의 활성 부위에 결합하는 것을 확인하였고, 이는 TTR 활성에 의해 유도되는 질병 조절 물질로의 적용 가능성이 있다고 판단된다. 결론적으로 일반 커큐민과 같은 생리 활성 효능 성분에 나노 마이셀링 기법을 적용하므로서 효율적인 결합 타깃 단백질 활발 조절 및 이러한 성분을 활용한 기능성 식품 산업에 나노 마이셀링 기법을 효율적으로 적용할 수 있음을 확인하였다.

중합촉매 시스템이 폴리페닐렌에테르의 합성에 미치는 영향 (The Effects of Polymerization Catalyst Systems on the Synthesis of Poly(2,6-dimethyl-1,4-phenylene ether))

  • 이창재;김용태;김진규;김지흥;남성우;전붕수;김영준
    • 폴리머
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    • 제36권1호
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    • pp.98-103
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    • 2012
  • 구리 계열의 $Cu(NO_2)_2{\cdot}3H_2O$와 CuCl을 중합촉매로 사용하고 다양한 용매, 리간드와 염기의 함량을 변화시켜 poly(2,6-dimethyl-1,4-phenylene ether)(PPE) 중합반응을 고찰하였다. 이 가운데 CuCl/1-methylimidazole/ammonium hydroxide 시스템에서 가장 높은 중합 수율을 나타내었다. 한편, 몇 가지 다른 유기용매와 메탄올의 혼합용매 시스템에서 용매의 성분비율을 변화시켜 용매의 조성이 중합반응에 미치는 영향을 조사하였으며 2,4,6-trimethylphenol (TMP)를 사용하여 TMP 함량에 따른 분자량 조절 효과를 조사하였다. 클로로포름/메탄올 9/1(v/v) 혼합용매를 사용했을 때 가장 높은 중합 수율과 높은 분자량을 갖는 중합체($\overline{M_n}$ : 55 K; $\overline{M_w}$ : 92 K; PDI: 1.7)를 얻었다. 구리 일가 촉매인 CuCl 과 CuI를 사용하여 서로다른 짝이온, 즉 $Ci^-$$I^-$ 이온이 중합결과에 미치는 영향을 조사하였다. 촉매의 활성 비교를 위하여 산소 흡수량(oxygen-uptake)을 측정하였으며, 중합반응의 부산물인 5,5'-tetramethyl-4,4'-diphenoquinone (DPQ)의 함량을 자외선 분광기(ultraviolet spectroscopy)를 통하여 분석하였다.

Anomalous Luminescence and Emission Quenching Behaviors of Tris(2,2$^\prime$-bipyridine)Ruthenium(Ⅱ) in Poly(methacrylic acid) Solutions$^1$

  • Park, Joon-Woo;Paik, Young-Hee
    • Bulletin of the Korean Chemical Society
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    • 제7권2호
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    • pp.137-142
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    • 1986
  • The luminescence spectra of $Ru(bpy)_3^{2+}$ in poly(methacrylic acid) (PMA) solutions varied sensitively with pH. At pH < 5.5, the emission intensity increased with pH up to 4 times, while it decreased with pH beyond the pH. The enhanced emission intensity was accompanied by blue-shift of the emission maxima as much as 15 nm. The enhancement of emission intensity was attributed to the restricted rotational mobility of ligand of the cation bound to densely coiled PMA molecules at pH < 5.5. The sharp decrease in emission intensity with increasing pH near pH 5.6 was accounted for conformational transition of the polymer to more extended structure, which was also revealed in viscosity measurement. The enhancement of emission intensity became higher as NaCl concentration of the solution increased. The binding constant of $Ru(bpy)_3^{2+}$ with two carboxylate groups of PMA was calculated as $2{\times}10^5\;M^{-1}$ in 0.1 M NaCl at pH 5.2. The pH dependence of luminescence quenching rate of $Ru(bpy)_3^{2+}$ by $Cu^{++}$ also showed maximum near pH 5, and the rate was more than $10^3$ times higher than that in water, whereas the maximum enhancement of quenching rate (about 20 times) in poly(acrylic acid) (PAA) solution occurred at pH 4.5. On the other hand, the pH dependence for neutral water soluble nitrobenzene (NB) exhibited opposite trend to that of $Cu^{++}$. The quenching constant vs pH curve for $MV^{++}$ was composite of those for $Cu^{++}$ and NB. The anomalous high quenching rate for $Cu^{++}$ in PMA solution at pH < 5.5 was attributed to the binding of $Ru(bpy)_3^{2+}$ and $Cu^{++}$ to the same region of PMA, when it conforms densely coiled structure in the pH range. The observation of mininium quenching rate for NB near pH 5.5 indicated that the $Ru(bpy)_3^{2+}$ bound to the densely coiled PMA is not accessible by NB, which is in bulk water phase. The composite nature of the pH dependence of quenching rate for $MV^{++}$ in PMA solution was attributed to the smaller binding affinity of the cation to PMA, compared to that of $Cu^{++}$. The sharp, cooperative conformational transition with pH observed in PMA was not revealed in PAA. But, the pH dependence of quenching rates in this polymer reflected increased charge density and, thus, binding of cations to the polymer, and expansion of the polymer chain with pH.

Whole genome MBD-seq and RRBS analyses reveal that hypermethylation of gastrointestinal hormone receptors is associated with gastric carcinogenesis

  • Kim, Hee-Jin;Kang, Tae-Wook;Haam, Keeok;Kim, Mirang;Kim, Seon-Kyu;Kim, Seon-Young;Lee, Sang-Il;Song, Kyu-Sang;Jeong, Hyun-Yong;Kim, Yong Sung
    • Experimental and Molecular Medicine
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    • 제50권12호
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    • pp.1.1-1.14
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    • 2018
  • DNA methylation is a regulatory mechanism in epigenetics that is frequently altered during human carcinogenesis. To detect critical methylation events associated with gastric cancer (GC), we compared three DNA methylomes from gastric mucosa (GM), intestinal metaplasia (IM), and gastric tumor (GT) cells that were microscopically dissected from an intestinal-type early gastric cancer (EGC) using methylated DNA binding domain sequencing (MBD-seq) and reduced representation bisulfite sequencing (RRBS) analysis. In this study, we focused on differentially methylated promoters (DMPs) that could be directly associated with gene expression. We detected 2,761 and 677 DMPs between the GT and GM by MBD-seq and RRBS, respectively, and for a total of 3,035 DMPs. Then, 514 (17%) of all DMPs were detected in the IM genome, which is a precancer of GC, supporting that some DMPs might represent an early event in gastric carcinogenesis. A pathway analysis of all DMPs demonstrated that 59 G protein-coupled receptor (GPCR) genes linked to the hypermethylated DMPs were significantly enriched in a neuroactive ligand-receptor interaction pathway. Furthermore, among the 59 GPCRs, six GI hormone receptor genes (NPY1R, PPYR1, PTGDR, PTGER2, PTGER3, and SSTR2) that play an inhibitory role in the secretion of gastrin or gastric acid were selected and validated as potential biomarkers for the diagnosis or prognosis of GC patients in two cohorts. These data suggest that the loss of function of gastrointestinal (GI) hormone receptors by promoter methylation may lead to gastric carcinogenesis because gastrin and gastric acid have been known to play a role in cell differentiation and carcinogenesis in the GI tract.

Interaction of the Post-transition Metal Ions and New Macrocycles in Solution

  • Jung, Oh-Jin
    • Bulletin of the Korean Chemical Society
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    • 제14권6호
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    • pp.687-691
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    • 1993
  • Complexation of $Cd^{2+},\;Pb^{2+}\;and\;Hg^{2+}$ ions with four cryptands were studied by potentiometry and solution calorimetry in various weight percent methanol-aqueous solvent at 25${\circ}$C under $CO_2$free nitrogen atmosphere. The stabilities of the complexes were dependent on the cavity size of macrocycles. The $Hg^{2+}$ ion stability constants are higher than those of $Cd^{2+}\;and\;Pb^{2+}$ ion. All the cryptands formed complexes having 1 : 1 (metal to ligand) mole-ratio except for $Hg^{2+}-L_1$ (cryptand 1,2b: 3,5-benzo-9,14,17-trioxa-1,7-diazabicyclo-(8,5,5) heptadecane) and $Cd^{2+}-L_2$ (cryptand 2,2b: 3,5-benzo-10,13,18,21-tetraoxa-1,7-diazabicyclo (8,5,5) eicosane) complexes. $Hg^{2+}-L_1$ complex was a sandwitch type, and the $Cd^{2+}-L_2$ complex showed two stepwise reactions. Thermodynamic parameters of the $Cd^{2+}-L_2$ complex were $6.08(log\;K_1)$, -7.28 Kcal/mol $({\Delta}H_1)$, and $4.78\;(log\;K_2)$, -4.62 Kcal/mol $({\Delta}H_2)$, respectively, for 1 : 1 and 2: 1 mole-ratio. The sequences of the selectivity were increased in the order of $Hg^{2+}\;>Pb^{2+}\;>Cd^{2+}$ ion for $L_3\;and\;L_4$ macrocycles, and the $L_2$-macrocycle has a selectivity for $Cd^{2+}$ ion relative to $Zn^{2+},\;Ni^{2+},\;Pb^{2+}\;and\;Hg^{2+}$ ions. Thus, it is expected that the $L_2$ can be used as carrier for seperation of the post transition metals by macrocycles-mediated liquid membrane because $L_2$ is not soluble in water, and the difference of stability constants of the metal complexes with $L_2$ are large as compared with the other transition metal complexes. The $^1H\;and\;^{13}C-NMR studies indicated that the nitrogen atoms of cryptands have greater affinity to the post transition metal ions than the oxygen atoms, and that the planarities of the macrocycles were lost by complexation with the metal ions because of the perturbation of ring current of benzene molecule attached to macrocycles and counter-anions.