Cucurbit[n]uril Derivatives Soluble in Water and Organic Solvents

Zhao, Jianzhang; Kim, Hee‐Joon; Oh, Jinho; Kim, Soo‐Young; Lee, Jae Woo; Sakamoto, Shigeru; Yamaguchi, Kentaro; Kim, Kimoon

doi:10.1002/1521-3773(20011119)40:22<4233::aid-anie4233>3.0.co;2-d

Cited by 228 publications

(124 citation statements)

References 36 publications

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“…Meat and fish are commonly wrapped in aluminum foil prior to oven cooking. Aluminum can reduce the growth rate of human brain cells, more effectively at higher concentrations (Exley et al, 2001;Zhao et al, 2001). Before 1980, Daily intakes of aluminum were reported to be 18-36 mg per day.…”

Section: Introductionmentioning

confidence: 77%

Aluminum Intoxication through Leaching in Food Preparation

Jabeen

Ali

Khan

et al. 2016

Alexandria Science Exchange Journal: An International Quarterly

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This study has been conducted to identify the correlation between food and aluminum intoxication through leaching. The ingestion is the main route of Aluminum exposure to the human body. Hence it is necessary to identify the aluminum levels in human body leached out from aluminum wares and aluminum foil. Pieces of chicken and red meat were baked with different types of solutions containing tomato juice, fresh yoghurt, salt and vinegar in different combinations, they were wrapped in aluminum foil in different combinations, marinated in aluminum pan and were tested for the pH and weight of pieces and foil. The result showed that citric acid with combination of lactic acid becomes the source for elevated level of aluminum in food items especially in raw beef. Citric acid with combination of tomato juice had highest accumulation rate than other solutions i.e 292.25mg/Kg in beef, while chicken leaching rate was 209.52mg/kg by the combination of yogurt and lemon juice. The fact still remains that once aluminum exceeds the acceptable limit from daily ingestion of food cooked in these pots, coupled with other sources from the environment. This environmental factor may contribute in increase of neurodegenerative diseases. The aim of this research study is to detect leaching out of aluminum levels from aluminum foil in different food solutions as it is becoming a common practice.

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Section: Introductionmentioning

confidence: 77%

Aluminum Intoxication through Leaching in Food Preparation

Jabeen

Ali

Khan

et al. 2016

Alexandria Science Exchange Journal: An International Quarterly

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“…A basicidade destes compostos é bastante baixa sendo verificados pKa's do ácido conjugado do CB [6] da ordem de 3, sendo desconhecida para os outros cucurbitandos. Uma das estratégias para contornar o problema de solubilidade é a utilização de meios salinos ou ácidos para aumentar a solubilidade destes compostos pela formação de complexos com ácidos duros ou, ainda, pela protonação das carbonilas dos opérculos destas estruturas 12 4,7,[16][17][18][19][20][21][22][23][24][25][26][27] . A reação de CB [6], por exemplo com K 2 S 2 O 8 , dá origem a 12 grupos OH radiais nos carbonos terciários em meio aquoso 22,28 , enquanto que a utilização de dimetil glicolurila como monômero precursor dá origem à decametil-CB [5] …”

Section: Síntese E Propriedades Físico-químicasunclassified

Cucurbiturilas

Demets¹

2007

Quím. Nova

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Recebido em 7/8/06; aceito em 9/11/06; publicado na web em 17/7/07 CUCURBITURILS. This review article describes the properties and the main applications of the glicol[n]urils. These compounds are cavitands made of n glycolurilic units arranged in circles, giving rise to extremely symmetric toroidal molecules. The cucurbit [n]urils create this way variable-sized hydrophobic cavities and the glycolurilic carbonyles delimit two portals on these cavities, slightly narrower than their internal radii. Their structure, physical and chemical properties favor the formation of inclusion compounds, and turn them into important building blocks for supramolecular chemistry and nanotechnology.Keywords: cucurbiturils; cucurbitands; inclusion compounds. INTRODUÇÃOAs cucurbiturilas foram sintetizadas pela primeira vez por Behrend e colaboradores 1 em 1905, como resultado da condensação da uréia e do glioxal, formando glicolurila e análogos poliméricos na presença de formaldeído. A tecnologia da época não permitiu uma caracterização inequívoca e a estrutura peculiar destes polímeros só foi elucidada pelo grupo de Mock, 80 anos mais tarde 2 . Pela primeira vez demonstrou-se que os cucurbitandos, outra designação desta família de compostos (abreviados também por CB[n]), eram estruturas cíclicas toroidais, compostas por 6 unidades de glicolurila, ligadas por grupos -CH 2 -em suas aminas de simetria D 6H (Figura 1).A nomenclatura oficial deste composto é complexa* e a sua forma de abóbora deu origem a seu nome, de cucurbita em latim (* segundo a IUPAC, o nome da cucurbit[6]urila ou CB[6] seria: dodecaidro-1H, 4H, 14H, 17H-2, 16:3, 15-dimetano-5H, 6H, 7H, 8H, 9H, 10H, 11H, 12H, 13H, 18H, 19H, 20H, 21H, 22H, 23H, 24H, 25H, 26H-2, 3-4a, 5a, 6a, 7a, 8a, 9a, 10a, 11a, 12a, 13a, 15, 16, 17a, 18a, 19a, 20a, 21a, 22a, 23a, 24a, 2 -3 -5a, 26a -tetracosaazabispentaleno[1''',6''':5'',6'',7'']cicloocta[1'', 2'', 3'':3', 4']pentaleno(1',6':5,6,7)cicloocta(1,2,3-gh:1',2',3'-g'h')cicloocta(1, 2, 3-cd:5, 6, 7-c'd')dipentaleno-1, 4, 6, 8, 10, 12, 14, 17, 19, 21, 23, 25-dodecona).Esta estrutura, além de ser simétrica, possui uma cavidade central hidrofóbica relativamente grande, que é capaz de acomodar espécies variadas para a formação de compostos de inclusão, também chamados de caviplexos, como o fazem outras famílias de cavitandos como as ciclodextrinas ou calixarenos. Na cucurbit[6]urila, existem 12 carbonilas orientadas para fora das cavidades, 6 de cada lado, formando assim dois portais para as cavidades, e conferindo à molé-cula um caráter básico de Lewis. Os métodos mais modernos de análise constataram que não eram formados apenas anéis de 6 membros nas sínteses de cucurbiturilas, mas que outros análogos cíclicos com 5 a 11 unidades glicolurílicas também eram formados durante as sínteses. Os recentes avanços em química orgânica sintética permitiram a elaboração de novas rotas, resultando em rendimentos diferenciados na produção destes homólogos. O maior controle sobre a distribuição dos produtos síntese tornou viável a síntese de CB [7] e ...

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“…Recently, a series of Q[n] derivatives including fully substituted cyclohexano Q [5] and Q [6] [13] , diphenyl Q [6] [14] , perhydroxycucurbit [6]uril ((OH) 12 Q [6]) [15] and others [16][17][18][19][20] were synthesized and reported to overcome the poor solubility of the general Q[n]s in common solvents. More recently, using a dimer of glycoluril synthesized in our laboratories and the diether of alkylglycoluril, we synthesized new symmetrical and unsymmetrical substituted cucurbit[n]urils [21] .…”

Section: Introductionmentioning

confidence: 99%

“…Similar to the well-known receptors or hosts such as crown ethers, cyclodextrins and calix[n]arenas, the interaction between the Q[n]s and guests can be investigated using various NMR methods, including 1 H NMR, 13 C NMR, COSY and NOESY techniques, mass spectrometry, X-ray crystallography, electronic absorption spectroscopy, and fluorescence spectroscopy. Generally, these methods give a consistent conclusion or some supporting information for a certain host-guest interaction system.…”

Section: Introductionmentioning

confidence: 99%

Host-guest complexes of a water soluble cucurbit[6]uril derivative with some dications of 1,ω-alkyldipyridines: 1H NMR and X-ray structures

Xiao

Zhang

Zhu

et al. 2009

Sci. China Ser. B-Chem.

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Interactions between a symmetrical tetramethyl-substituted cucurbit[6]uril (host: TMeQ[6]) and 1,ω-alkylenedipyridine (ω = 2, 4, 6, 8,10) dicationic guests were investigated using 1 H NMR spectroscopy and single crystal X-ray crystallography. In these inclusion complexes, combined cavity and portal binding in TMeQ[6] were observed, and the length of the bridged alkylene was found to play an important role not only in balancing the overall hydrophilic/hydrophobic interaction between the host and the guest, but also in defining the structure of the resulting inclusion complexes. For the guest 1,2-ethylenedipyridine (Edpy), TMeQ[6] includes a positively charged pyridine ring of Edpy to form an unsymmetrical inclusion complex; for the guest 1,4-butylenedipyridine (Bdpy), TMeQ[6] includes a positively charged pyridine ring of Bdpy, but the different competitive interactions in and between the related inclusion complexes could lead to a fast exchange between the hosts and guests. For the guests with longer bridge chains, such as 1,6-hexamethylenedipyridine (Hdpy) or 1,8-octylenedipyridine (Odpy), a stable pseudorotaxane inclusion complex is formed by combining the hydrophobic cavity and the outer portal dipole-ion interactions. However, for 1,10-decatylenedipyridine (Ddpy), the two TMeQ[6] host molecules include the two end pyridine rings of Ddpy and form a dumbbell inclusion complex.symmetrical tetramethyl-substituted cucurbit[6]uril, 1,ω-alkylenedipyridine (ω = 2, 4, 6, 8, 10) dicationic guests, host-guest complex, 1 H NMR spectroscopy, single crystal X-ray crystallography

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Cucurbit[n]uril Derivatives Soluble in Water and Organic Solvents

Cited by 228 publications

References 36 publications

Aluminum Intoxication through Leaching in Food Preparation

Aluminum Intoxication through Leaching in Food Preparation

Cucurbiturilas

Host-guest complexes of a water soluble cucurbit[6]uril derivative with some dications of 1,ω-alkyldipyridines: 1H NMR and X-ray structures

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