259886-50-5Relevant academic research and scientific papers
Photodeamination to quinone methides in cucurbit[n] urils: Potential application in drug delivery
?kalamera, Dani,Matkovi?, Marija,Uzelac, Lidija,Kralj, Marijeta,Mlinari?-Majerski, Kata,Bohne, Cornelia,Basari?, Nikola
, p. 8908 - 8912 (2018)
We demonstrate a proof of principle for a new approach in the development of a drug delivery system. A positively charged prodrug (phenol) can form a stable inclusion complex with CB[7], which enables more efficient delivery of the prodrug. After photochemical transformation (photoactivation) inside the complex, an active drug quinone methide (QM) is formed and released from the complex, since it is a neutral molecule and forms a less stable complex with CB[7].
SERS multiplexing of methylxanthine drug isomersviahost-guest size matching and machine learning
Chio, Weng-I Katherine,Dinish, U. S.,Jones, Tabitha,Lee, Tung-Chun,Liu, Jia,Olivo, Malini,Parkin, Ivan P.,Perumal, Jayakumar
supporting information, p. 12624 - 12632 (2021/10/06)
Multiplexed detection and quantification of structurally similar drug molecules, methylxanthine MeX, incl. theobromine TBR, theophylline TPH and caffeine CAF, have been demonstratedviasolution-based surface-enhanced Raman spectroscopy (SERS), achieving highly reproducible SERS signals with detection limits down to ～50 nM for TBR and TPH, and ～1 μM for CAF. Our SERS substrates are formed by aqueous self-assembly of gold nanoparticles (Au NPs) and supramolecular host molecules, cucurbit[n]urils (CBn,n= 7, 8). We demonstrate that the binding constants can be significantly increased using a host-guest size matching approach, which enables effective enrichment of analyte molecules in close proximity to the plasmonic hotspots. The dynamic range and the robustness of the sensing scheme can be extended using machine learning algorithms, which shows promise for potential applications in therapeutic drug monitoring, food processing, forensics and veterinary science.
Comparative study of inclusion complexation of tetraalkylphosphonium and ammonium salts with cucurbit[7]uril
Hagiwara, Seiya,Hanaya, Tadashi,Matsumoto, Yuki,Sueishi, Yoshimi
, (2020/07/13)
Inclusion complexation of tetraalkylphosphonium salts (PSs) with cucurbit[7]uril (CB[7]) was studied spectrophotometrically using methylene blue as a chemical indicator. Differences in the inclusion behaviour caused by the central ions in PSs and tetraalkylammonium salts (ASs) are described herein. The inclusion complexation constant (K) of PS3 with a C3-alkyl chain is remarkably smaller than those of the other PSs, indicating that PS3 is most suitable for clathrate-hydrate formation in bulk solution. In the AS inclusions, AS4 with a C4-alkyl chain showed the small K value. Furthermore, the K values of PSs with CB[7] were measured under high pressure. The K values of CB[7] increased with increasing external pressure and decreasing solvent polarity. From the high-pressure results, the volume change (ΔVrepel) caused by water molecules released from the CB[7] cavity was evaluated. A volumetric study for the inclusion of PSs with CB[7] indicated that in PS6 and PS8 with long C6 and C8 chains, respectively, one alkyl chain was encapsulated in the CB[7] cavity. In the other PSs with short chains, two alkyl chains could be accommodated in the cavity. Based on the effects of temperature, substituents, and external pressure, differences in the inclusion mechanisms of PSs and ASs for CB[7] are discussed.
Supramolecular assembly of poly(ionic liquid) nanogel driven by host-stabilized charge transfer interaction
Tang, Yuntao,Wang, Ke,Zuo, Yong,Chen, Xi,Xiong, Yubing,Yuan, Yumin
, p. 2251 - 2259 (2019/11/13)
Poly(ionic liquid) (PIL)-based nanogels, functionalized by naphthyl (Np), are fabricated via a facile one-step ternary crosslinking copolymerization in selective solvent. The size of PIL nanogels can be conveniently regulated through the feed ratio of IL monomer to crosslinker. The presence of Np groups in PIL nanogel is confirmed by using ultraviolet–visible (UV–vis), Fourier transform infrared, and X-ray photoelectron spectroscopy measurements. Through introducing cucurbit[8]uril (CB[8]) and bisviologen compound (DEDV) as the host molecule and electron acceptor, respectively, host-stabilized charge transfer (HSCT) interaction is achieved through utilizing Np containing PIL nanogel as the building block. The studies reveal that PIL nanogels can form schistose aggregates in the scale of micrometer via HSCT interaction. The aggregates will be broken in the presence a competitive guest molecule (amantadine) and can recover by adding another host molecule (CB[7]). HSCT interaction among CB[8], DEDV and PIL nanogel is investigated by dynamic light scattering, UV–vis, and Proton nuclear magnetic resonance. Our studies thus provided an applicable strategy for constructing dynamic polymer nanoparticles through noncovalent interaction.
PROCESS FOR THE PREPARATION OF CUCURBITURIL DERIVATIVES
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Page/Page column 14; 15, (2018/07/22)
This invention relates to cucurbituril and/or one or more derivatives thereof with low formaldehyde content, to a process of manufacturing said cucurbituril and/or one or more derivatives thereof and to the use of said cucurbituril and/or one or more derivatives thereof, in particular in consumer and industrial products, and in industrial processes.
Cucurbit[n]uril formation proceeds by step-growth cyclo-oligomerization
Huang, Wei-Hao,Zavalij, Peter Y.,Isaacs, Lyle
supporting information; scheme or table, p. 8446 - 8454 (2009/02/02)
In contrast to the high yield formation of cucurbit[n]uril (CB[n]) from a 1:2 ratio of glycoluril to formaldehyde, the condensation of glycoluril with less than 2 equiv of formaldehyde delivers a reaction mixture that contains glycoluril oligomers (2-6) and CB[n] compounds that lack one or more methylene bridges known as nor-seco-cucurbit[n]urils (ns-CB[n]). In this paper we report the chromatographic purification of C-shaped glycoluril oligomers (dimer-hexamer), their characterization in solution, and their X-ray crystal structures. Quite interestingly, despite being acyclic glycoluril pentamer 5 and hexamer 6 retain the ability to bind to guests typical of CB[6] but are also able to expand their cavity to accommodate larger guests like cationic adamantane derivatives. We performed product resubmission experiments with glycoluril oligomers 2-6 and found preferences for the formation of specific ring sizes during CB[n] formation. A comprehensive mechanistic scheme is proposed that accounts for the observed formation of 2-6 and ns-CB[n]. Overall, the experiments establish that a step-growth cyclo-oligomerization process operates during CB[n] formation.
Mechanism of the conversion of inverted CB[6] to CB[6]
Liu, Simin,Kim, Kimoon,Isaacs, Lyle
, p. 6840 - 6847 (2008/02/11)
(Figure Presented) Inverted cucurbit[n]urils (iCB[n]) form as intermediates during the synthesis of cucurbit[n]urils from glycoluril and formaldehyde in HCl (85°C). Product resubmission experiments establish that the diastereomeric iCB[6] and iCB[7] are kinetic products that are less stable thermodynamically than CB[6] or CB[7] (>2.8 kcal mol-1). When iCB[6] or iCB[7] is heated under aqueous acidic conditions, a preference for ring contraction is noted in the formation of CB[5] and CB[6], respectively. Interestingly, under anhydrous acidic conditions ring size is preserved with iCB[6] delivering CB[6] cleanly. To establish the intramolecular nature of the iCB[6] to CB[6] conversion under anhydrous, but not aqueous, acidic conditions we performed crossover experiments involving mixtures of iCB[6] and its 13C=O labeled isotopomer 13C12-iCB[6]. An unusual diastereomeric CB[6] with a Moebius geometry (13) is proposed as a mechanistic intermediate in the conversion of iCB[6] to CB[6] under anhydrous acidic conditions. The improved mechanistic understanding provided by this study suggests improved routes to CB[n]-type compounds.
Salt Effects on the Apparent Stability of the Cucurbit[7]uril-Methyl Viologen Inclusion Complex
Ong, Winston,Kaifer, Angel E.
, p. 1383 - 1385 (2007/10/03)
The effects of the medium ionic composition on the apparent equilibrium association constant (K) for the formation of a 1:1 inclusion complex between the guest methyl viologen (MV2+) and the host cucurbit[7]uril (CB7) were studied in aqueous solutions. The K values were found to decrease with increasing ionic strength, with more pronounced effects for solutions containing divalent Ca2+ ions than for solutions containing monovalent Na+ ions. The competing ion-dipole interactions between Ca2+ or Na+ and MV2+ ions appear to be responsible for the remarkable modulation of the K values observed in this work.
Binding selectivity of cucurbit[7]uril: Bis(pyridinium)-1,4-xylylene versus 4,4′-bipyridinium guest sites
Sindelar, Vladimir,Moon, Kwangyul,Kaifer, Angel E.
, p. 2665 - 2668 (2007/10/03)
The binding interactions between the host cucurbit[7]uril (CB7) and a series of linear guests containing bis(pyridinium)-1,4-xylylene and/or 4,4′-bipyridinium residues were investigated by 1H NMR spectroscopy. CB7 was found to exhibit considerable binding selectivity for bis-(pyridinium)-1,4-xylylene over 4,4′-bipyridinium sites. New pseudo-rotaxane and rotaxane compounds were synthesized utilizing the host-guest interactions between CB7 and the surveyed guests.
Controlling factors in the synthesis of cucurbituril and its homologues
Day, Anthony,Arnold, Alan P.,Blanch, Rodney J.,Snushall, Barry
, p. 8094 - 8100 (2007/10/03)
The acid-catalyzed synthesis of cucurbit[n]urils from formaldehyde and glycoluril is poorly understood. In this paper, we examine a wide range of reaction conditions that include the effects of acid type, acid concentration, reactant concentrations, and temperature to both probe the mechanism and optimize the yields of isolated cucurbit[n]urils, where n = 5-10. A mechanism for the formation of these cucurbit[n]urils is presented. Individual cucurbit[n]urils were unambiguously identified in reaction mixtures using ESMS and 13C NMR.
