A new synthesis of p-nitrocalix[6]arene

Shinkai, Seiji; Tsubaki, Takayuki; Sone, Takaaki; Manabe, Osamu

doi:10.1016/s0040-4039(00)98293-5

Cited by 33 publications

(30 citation statements)

References 5 publications

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“…This means that the precise structure of CA molecules affects aggregation in a more complex way than in the case of classic surfactants. However, in this series of aminoCAs (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18), a correlation of aggregate size with CMC values has been revealed ( Table 4). 21 The effect of modification of aminoCA upper rim on surface activity has also been shown.…”

Section: Surface Activitymentioning

confidence: 84%

“…These parasulfonato-CAs (PSCAs) were then employed for production of nitro-substituted forms which, in turn, could be transformed to cationic aminoCAs. [16][17][18] An alternative synthetic pathway for methoxy-substituted aminocalix [4]arenes, via a chloromethylated intermediate, was described shortly after. 19 Simultaneously, the first anionic CAs bearing carboxyls at lower rim were successfully produced by two independent research groups.…”

Section: History Of Calix[n]arenes Synthesis Of Hydrophilic Derivativesmentioning

confidence: 99%

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Encapsulation of Drug Molecules into Calix[n]arene Nanobaskets. Role of Aminocalix[n]arenes in Biopharmaceutical Field

Ukhatskaya

Kurkov

Matthews

et al. 2013

Journal of Pharmaceutical Sciences

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Section: Surface Activitymentioning

confidence: 84%

Section: History Of Calix[n]arenes Synthesis Of Hydrophilic Derivativesmentioning

confidence: 99%

Encapsulation of Drug Molecules into Calix[n]arene Nanobaskets. Role of Aminocalix[n]arenes in Biopharmaceutical Field

Ukhatskaya

Kurkov

Matthews

et al. 2013

Journal of Pharmaceutical Sciences

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“…21) Shinkai et al reported the preparation of p-sulfonato calix [6] arene. 22) Other anionic water-soluble derivatives containing nitro, 23) phosphonic acid, 24) and carboxyl 25) moieties emerged, and the first example of a cationic water-soluble calixarene was reported by Shinkai et al 26) Other cationic calixarenes contain tetraalkylammonium groups and primary amines. [27][28][29] Neutral water-soluble calixarenes have been synthesized with sulfonamides, 30) sugars, 31) and polyoxyethylene.…”

mentioning

confidence: 99%

Preparation and Characterization of Amphiphilic Calixarene Nanoparticles as Delivery Carriers for Paclitaxel

Zhao

Wang

Han

et al. 2015

CHEMICAL & PHARMACEUTICAL BULLETIN

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Two types of amphoteric calix[n]arene carboxylic acid (CnCA) derivative, i.e., calix[6]arene hexa-carboxylic acid (C 6 HCA) and calix[8]arene octo-carboxylic acid (C 8 OCA), were synthesized by introducing acetoxyls into the hydroxyls of calix[n]arene (n 6, 8). C 6 HCA and C 8 OCA nanoparticles (NPs) were prepared successfully using the dialysis method. CnCA NPs had regular spherical shapes with an average diameter of 180-220 nm and possessed negative charges of greater than 30 mV. C 6 HCA and C 8 OCA NPs were stable in 4.5% bovine serum albumin solutions and buffers (pH 5-9), with a low critical aggregation concentration value of 5.7 mg·L 1 and 4.0 mg·L 1 , respectively. C 6 HCA and C 8 OCA NPs exhibited good paclitaxel (PTX) loading capacity, with drug loading contents of 7.5% and 8.3%, respectively. The overall in vitro release behavior of PTX from the CnCA NPs was sustained, and C 8 OCA NPs had a slower release rate compared with C 6 HCA NPs. These favorable properties of CnCA NPs make them promising nanocarriers for tumortargeted drug delivery.Key words calix[n]arene carboxylic acid; nanoparticle; paclitaxel; tumor therapy Paclitaxel (PTX) is a well-known anticancer drug that is used primarily to treat lung, breast and ovarian cancers. Similar to most anticancer drugs, its poor solubility in water limits the clinical applications of PTX. Taxol, a widely used clinical formulation of paclitaxel, requires the use of Cremphor-EL as a solubilizer, which has been known to cause serious problems, including hypersensitivity reactions, neurotoxicity, and nephrotoxicity.1,2) Moreover, the lack of selectivity of PTX results in significant toxicity to noncancerous cells and severely impacts patients' quality of life. Therefore, there is a dire need for the development of a novel formulation that improves the solubility of PTX and decreases its side effects.Among various alternatives, nano-sized drug delivery system (nano-DDS) is one of the best choices. Nano-DDS not only greatly enhances the solubility of PTX without side effects, but it also promotes intra-tumoral drug accumulation through the enhanced permeability and retention (EPR) effect.3,4) Many nano-DDSs of PTX have been reported, and some of them have been marketed. Abraxane, a nanosuspension of paclitaxel encapsulated in human albumin was approved by the Food and Drug Administration (FDA) in 2005 for the treatment of metastatic breast cancer.5) A liposomebased PTX formulation, Lipusu, has been applied for the treatment of ovarian cancer in China.6) In addition to these approved drugs, a number of PTX nano-DDSs, such as polymeric nanoparticles (NPs), 7-9) inorganic NPs, 10) nano-emulsions, 11) carbon nanotubes, 12) and nanogels, 13) have been reported in preclinical studies. Although these novel PTX nano-DDSs exhibit varying levels of success, methods for improving the safety, stability and specificity of nano-DDS still warrant further research.Calixarenes have been used as an important class of macrocyclic host molecules in supramolecular chemistry.14) Becaus...

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“…The complex formation reaction of p-nitrocalix [6]arene, CALX-N6, with a uranyl ion, UO2 2 , was studied by the pH titration method in a 20 acetone aqueous solution at 20 and µ 0.01. From the absorption data of CALX-N6, the acid dissociation constants were determined to be as follows : pK a1 2.72, pK a2 5.71 and pK a3 11.59.…”

mentioning

confidence: 99%