92003-62-8Relevant articles and documents
Complexation characteristics of permethylated cycloinulohexaose, cycloinuloheptaose, and cycloinulooctaose with metal cations
Shizuma, Motohiro,Takai, Yoshio,Kawamura, Mishio,Takeda, Tokuji,Sawada, Masami
, p. 1306 - 1314 (2001)
The host-guest complexation behavior of cyclic oligosaccharides, permethylated cycloinulohexaose 1, permethylated cycloinuloheptaose 2, and permethylated cycloinulooctaose 3 with metal cations has been characterized by means of UV-visible, NMR, and electrospray ionization (ESI) mass spectrometry. In the crystal state, the structures of 1·K+, 1·Rb+, and 1·Cs+ were same as that of the 1·Ba2+ complex which has a u-u-d-u-u-d (u = up, d = down) furanose ring arrangement for the plane of the crown ring moiety. The association constants (Ks) in THF and in [2H6]acetone at 298 K were evaluated. The binding ability of host 1 with metal cations was of the same degree as that of calix[6]arene derivative 4 and much higher than those of hosts 2 and 3. The thermodynamic parameters of the complexation of host 1 with metal cation in THF were determined, and it was suggested that the entropy change for the solvation of the metal cations was one of the important factors in the complexation equilibrium. It was clarified that the structure of the host 1·K+ complex in solution at low temperature (furanose ring arrangement: u-d-u-d-u-d) was different from that in the crystal state (u-u-d-u-u-d arrangement) by the coalescence behavior in 1H-NMR. The relative peak intensity of the complex ions of host 1 or 2 with two alkali metal ions in ESI mass spectrometry (in acetone) showed a correlation in the first order approximation with the ratio of the corresponding complex ion concentrations estimated from the Ks values.
Syntheses of ester and amide derivatives of calix[6]arene and their complexation affinities towards La3+, Eu3+, and Yb3+
Tranfi? Baki?, Marina,Klari?, David,Espinosa, Maria Soledad,Kazazi?, Sa?a,Frkanec, Leo,Babay, Paola Alejandra,Gali?, Nives
, p. 723 - 731 (2019)
One hexaester (1) and three hexaamide derivatives (2–4) of calix[6]arenes were prepared for the first time in one synthetic step, under microwave radiation. Compounds 2 and 3 were novel ones, while ester calix[6]arene derivative 1 and amide derivative 4 were prepared previously, by conventional syntheses. Microwave-assisted syntheses shortened the reaction times from 48 to 2 h. The binding properties of calix[6]arenes towards selected lanthanide cations (La3+, Eu3+, Yb3+) were studied by spectroscopic and mass spectrometric techniques. No complexation was observed with the ester derivative, while compounds 2–4 formed 1:1 complexes. Based on spectrophotometric titrations, the stability constants of resulting complexes could only be estimated (lg K ≥ 6). Calixarene derivatives, as well as their complexes, were analysed by ESI MS and MS/MS spectrometry. Corresponding fragmentation pathways were proposed, and in some cases confirmed by MS3 experiments. The results obtained by different techniques were in accordance.
Synthesis, X-ray crystal structure and anti-tumor activity of calix[n]arene polyhydroxyamine derivatives
An, Lin,Han, Li-Li,Zheng, You-Guang,Peng, Xian-Na,Xue, Yun-Sheng,Gu, Xiao-Ke,Sun, Jing,Yan, Chao-Guo
, p. 21 - 30 (2016/08/01)
Calixarene-based compounds are highly effective therapeutic agents against cancer. This study aims to prepare a series of calix [n]arene (n?=?4, 6, 8) polyhydroxyamine derivatives (3a–3m) and to study their potential antitumor activities. The single crystal structure of calixs[4]arene derivative 3a was determined through X-ray diffraction. We assessed the ability of the prepared calix [n]arene polyhydroxyamine derivatives to induce cytotoxicity in six cancer cell lines by performing cancer cell growth inhibition assays. Results demonstrated that compounds 3a–3d achieved IC50values ranging from 1.6?μM to 11.3?μM. Among the different compounds, 3a and 3b exerted the strongest cytotoxic effect in inhibiting the growth of SKOV3 cells. In relation to the underlying mechanisms of cytotoxic effects, cell cycle analysis revealed that the exposure of SKOV3 cells to 3a induced cell cycle arrest in the G0/G1 phase, suggesting a reduction in DNA synthesis. Immunofluorescent staining indicated that the protein expression levels of caspase-3 and p53 in cells significantly increased, whereas that of Bcl-2 was effectively suppressed. Meanwhile, no significant changes in Bax were observed in SKOV3 cells. These results highlight that calixarene 3a can be further studied as a potential anticancer agent.
Novel synthesis of calix[n]arene amidoazobenzene derivatives
An, Lin,Cai, Ya Hua,Wang, Min-Hua,Yan, Chao Guo
, p. 75 - 77 (2007/10/03)
A series of calix[n]arenas and calix[4]resorciarenes containing azo chromophores on the lower rim were synthesised with two routes. The first direct route involved alkylating calixarenes with 4-chloroacetoaminoazobenzene. The second indirect route was by acylating 4-aminoazobenzene with calix[n]arylacetyl chloride. Their extracting abilities for transition metal ions were tested.
