Hydrolysis of Cyclodextrin by Aspergillus oryzae α‐Amylase

Jodái, I.; Kandra, Lili; Harangi, János; Nánási, Pál; Debrecen,; Szejtli, J.

doi:10.1002/star.19840360408

Cited by 50 publications

(11 citation statements)

References 9 publications

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“…Considering that α-amylase is capable of hydrolyzing CDs 47, we also investigated the stability of OCD NP in aqueous solution of α-amylase. It was found that OCD NP was relatively stable for at least 24 h in the presence of α-amylase ( Figure S4A ).…”

Section: Resultsmentioning

confidence: 99%

A Multifunctional Nanotherapy for Targeted Treatment of Colon Cancer by Simultaneously Regulating Tumor Microenvironment

Zhang¹,

Zhang²,

Li³

et al. 2019

Theranostics

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Colitis-associated colon cancer (CAC) is a widely recognized cancer, while treatment with the existing chemotherapeutic drugs affords limited clinical benefits. Herein we proposed a site-specific, combination nanotherapy strategy for targeted treatment of CAC by the oral route. Methods : A reactive oxygen species (ROS)-responsive and hydrogen peroxide-eliminating material OCD was synthesized, which was further produced into a functional nanoparticle (OCD NP). The antioxidative stress and anti-inflammatory effects of OCD NP were examined by in vitro and in vivo experiments. By packaging an anticancer drug camptothecin-11 (CPT-11) into OCD NP, a ROS-responsive nanotherapy CPT-11/OCD NP was obtained, and its antitumor activity was evaluated by both in vitro and in vivo studies. Preliminary safety studies were also performed for CPT-11/OCD NP in mice. Results : OCD NP significantly attenuated oxidative stress and inhibited inflammatory response in different cells and mice with induced colitis. CPT-11/OCD NP could selectively release drug molecules under intestinal pH conditions and at high levels of ROS. In C26 murine colon carcinoma cells, this nanotherapy showed significantly higher antitumor activity compared to free CPT-11 and a non-responsive CPT-11 nanotherapy. Correspondingly, oral delivery of CPT-11/OCD NP notably inhibited tumorigenesis and tumor growth in mice with induced CAC. By combination therapy with the nanovehicle OCD NP in the inflammatory phase, more desirable therapeutic effects were achieved. Furthermore, CPT-11/OCD NP displayed excellent safety profile for oral administration at a dose that is 87.3-fold higher than that employed in therapeutic studies. Conclusions : Anticancer nanotherapies derived from intrinsic anti-inflammatory nanocarriers are promising for targeted combination treatment of inflammation-associated tumors by simultaneously shaping pro-inflammatory microenvironment toward a relatively normal niche sensitive to chemotherapy.

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Section: Resultsmentioning

confidence: 99%

A Multifunctional Nanotherapy for Targeted Treatment of Colon Cancer by Simultaneously Regulating Tumor Microenvironment

Zhang¹,

Zhang²,

Li³

et al. 2019

Theranostics

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“…39). Additionally, the enzymatic reaction of the γ-CDs was found to be a self-regulated system, i.e., the products (maltooligomers, glucose, maltose) of the enzymatic reaction worked as feedback for the hydrolysis rate of the γ-CDs 55 , resulting in increased lifetimes after each cycle ( Fig. 5c, Supplementary Fig.…”

Section: Resultsmentioning

confidence: 99%

Color-tunable single-fluorophore supramolecular system with assembly-encoded emission

et al. 2020

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Regulating the fluorescent properties of organic small molecules in a controlled and dynamic manner has been a fundamental research goal. Although several strategies have been exploited, realizing multi-color molecular emission from a single fluorophore remains challenging. Herein, we demonstrate an emissive system by combining pyrene fluorophore and acylhydrazone units, which can generate multi-color switchable fluorescent emissions at different assembled states. Two kinds of supramolecular tools, amphiphilic self-assembly and γ-cyclodextrin mediated host-guest recognition, are used to manipulate the intermolecular aromatic stacking distances, resulting in the tunable fluorescent emission ranging from blue to yellow, including a pure white-light emission. Moreover, an external chemical signal, amylase, is introduced to control the assembly states of the system on a time scale, generating a distinct dynamic emission system. The dynamic properties of this multi-color fluorescent system can be also enabled in a hydrogel network, exhibiting a promising potential for intelligent fluorescent materials.

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“…The hydrolysis of a-, b-and c-cyclodextrins by Aspergillus oryzae a-amylase was studied at pH 5.2 and 37°C. The kinetic parameters were determined and while the V max value increased markedly in the order a-, b-and c-cyclodextrin the K m values did not show significant difference [9]. Some flexibility of c-cyclodextrin ring makes it susceptible for opening by amylases.…”

Section: Introductionmentioning

confidence: 99%

“…The active center of amylase enzymes has several subsites and the reaction speed depends on the length of the malto-oligomer [9,10]. This reaction was studied in details by Kandra et al [11][12][13] and a computer program was developed to determine the binding energy of the subsites of active center [14].…”

Section: Introductionmentioning

confidence: 99%

The digestable parent cyclodextrin

Harangi

Béke

Harangi

et al. 2011

J Incl Phenom Macrocycl Chem

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The enzymatic digestibility of parent c-cyclodextrin by human saliva a-amylase was investigated aiming at the determination of lifespan of intact macro ring. It was found that the ring-opening reaction was the slowest step of the c-cyclodextrin degradation process. The reaction products were mainly maltose and malto-triose, while no higher malto-oligomers were detected. The enzymatic degradation of c-cyclodextrin reduces the possibility of influencing bioavailability of nutritional lipophiles or drug actives co-administered with c-cyclodextrin as an excipient or additive. Though there are numerous papers on the ring opening of cyclodextrins by amylases and the same capability of the human a-amylase is expected now we prove this activity. The hydrolysis reaction was followed by direct measurement of the resulting maltose and maltotriose, for the first time.

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Hydrolysis of Cyclodextrin by Aspergillus oryzae α‐Amylase

Cited by 50 publications

References 9 publications

A Multifunctional Nanotherapy for Targeted Treatment of Colon Cancer by Simultaneously Regulating Tumor Microenvironment

A Multifunctional Nanotherapy for Targeted Treatment of Colon Cancer by Simultaneously Regulating Tumor Microenvironment

Color-tunable single-fluorophore supramolecular system with assembly-encoded emission

The digestable parent cyclodextrin

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