Jacek Dulęba

Mr. Jacek Dulęba

Department of Medicinal Chemistry, Collegium Medicum in Bydgoszcz, Faculty of Pharmacy, Nicolaus Copernicus University in Torun, Dr. A. Jurasza 2, 85-089 Bydgoszcz, Poland
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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 August 2020 in Catalysts
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Tomasz SiódmiakTomasz Siódmiak
Tomasz Siódmiak
GHGudmundur G. Haraldsson
Gudmundur G. Haraldsson
JDJacek Dulęba
Jacek Dulęba
MZMarta Ziegler-Borowska
Marta Ziegler-Borowska
JSJoanna Siódmiak
Joanna Siódmiak
MMMichał Piotr Marszałł
Michał Piotr Marszałł
Immobilized enzymatic catalysts are widely used in the chemical and pharmaceutical industries. As Candida antarctica lipase B (CALB) is one of the more commonly used biocatalysts, we attempted to design an optimal lipase-catalytic system. In order to do that, we investigated the enantioselectivity and lipolytic activity of CALB immobilized on 12 different supports. Immobilization of lipase on IB-D152 allowed us to achieve hyperactivation (178%) in lipolytic activity tests. Moreover, the conversion in enantioselective esterification increased 43-fold, when proceeding with lipase-immobilized on IB-S861. The immobilized form exhibited a constant high catalytic activity in the temperature range of 25 to 55 °C. Additionally, the lipase immobilized on IB-D152 exhibited a higher lipolytic activity in the pH range of 6 to 9 compared with the native form. Interestingly, our investigations showed that IB-S500 and IB-S60S offered a possibility of application in catalysis in both organic and aqueous solvents. A significant link between the reaction media, the substrates, the supports and the lipase was confirmed. In our enzymatic investigations, high-performance liquid chromatography (HPLC) and the titrimetric method, as well as the Bradford method were employed.

3 June 2020 in Current Organic Chemistry
Verified
Journal Article
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JDJacek Dulęba
Jacek Dulęba
Tomasz SiódmiakTomasz Siódmiak
Tomasz Siódmiak
MMMichał Piotr Marszałł
Michał Piotr Marszałł
: Lipases in the native or immobilized form have commonly been used as catalysts in the chemical and pharmaceutical industry. One of the widely available enzyme catalysts on the market is lipase from Burkholderia cepacia (BCLs), previously called Pseudomonas cepacia (PCLs). This enzyme is applied, among others, in the stereoselective acylation of molecules to achieve chiral pure enantiomers of drugs or their building blocks. In this study, Amano lipase PS (APS-BCL), which is a commercial lipase from Burkholderia cepacia (BC) was tested. The lipolytic activity of APS-BCL by hydrolysis of vegetable oils and enantioselective activity of APS-BCL by the kinetic resolution of (R,S)-1-phenylethanol with using isopropenyl acetate as an acyl donor were evaluated. An effect of reaction media with different logP values (t-butyl methyl ether, dichloromethane, diisopropyl ether, toluene, cyclohexane, n-hexane, isooctane and n-heptane) on the enantioselective activity of lipase was also studied. The high value of the enantiomeric ratio (E =308.5) with the utilization of isopropenyl acetate was achieved. Whereas, the best reaction medium turned out to be diisopropyl ether, C =47.9%, eep =98%, ees =90%, after 24 h of incubation. Moreover, the influence of ω6/ω9 polyunsaturated fatty acids (PUFAs) ratio in commercial (peanut, camelina, rape, pumpkin seed, walnut, sesame, avocado, rice, corn, black cumin, hemp, safflower, grape seed) oils was investigated for the lipase activity. For the first time, the cut-off limit of ω6/ω9 ratio was proposed. The ratio equal to or higher than 2.3 allows achieving higher lipolytic activity.

9 February 2021 in Healthcare
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Journal Article
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JDJacek Dulęba
Jacek Dulęba
Urszula ReligioniUrszula Religioni
Urszula Religioni
ESEmilia Słodka
Emilia Słodka
AFAndrzej Fal
Andrzej Fal
JKJerzy Krysiński
Jerzy Krysiński
Piotr MerksPiotr Merks
Piotr Merks
Background: Many OTC drugs are available in non-pharmacy outlets, and as such the risk of overuse and/or improper use of this class of drugs is more likely. In light of this observation, our study was conducted with the aim of exploring opinions on non-pharmaceutical distribution among Polish patients. This study was a part of an informative project to educate patients about the possible risks associated with the use of OTC medicines. Methods: We conducted a cross-sectional study among Polish patients in which we used an authorial questionnaire, previously tested via content, face validity, and a pilot study. The questionnaire was distributed both electronically and in a traditional form. Results: ‘Time saving’ had a statistically significant role in the patient’s decision about purchasing drugs in a non-pharmacy outlet (p = 0.0052; R = 0.276994). The lack of a pharmacist’s consultation/advice (p = 0.0072; R = −0.3290490), improper storage (p = 0.0044; R = −0.238246), risk of overdose (p = 0.0125; R = −0.189564), and the risk of purchasing out-of-date drugs (p = 0.0125; R = −0.145411), as well as the risk of purchasing falsified drugs (p = 0.0265; R = −0.159428), were all associated with the patient’s non-willingness to purchase drugs in non-pharmacy outlets. Patients supported the idea of the elimination of non-pharmacy outlet distribution (p = 0.0074; R = −0.195932); they also emphasized that they are advocates of purchasing drugs only in community pharmacies (p = 0.0006; R = −0.238625). Conclusion: Patients are aware of the risks associated with buying drugs outside of community pharmacies. They perceived pharmacists as professional health care advisors and supported the fact that OTC drugs should be available only via pharmaceutical distribution.

15 May 2023 in Catalysts
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Journal Article
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Tomasz SiódmiakTomasz Siódmiak
Tomasz Siódmiak
JDJacek Dulęba
Jacek Dulęba
GHGudmundur G. Haraldsson
Gudmundur G. Haraldsson
JSJoanna Siódmiak
Joanna Siódmiak
MMMichał Piotr Marszałł
Michał Piotr Marszałł
Thermal stability is one of the essential parameters characterizing biocatalysts with potential applications in the chemical and pharmaceutical industries. Therefore, it is extremely important to develop standardized procedures for enzyme stability studies. The paper attempts to assess the thermal stability of immobilized lipases in aqueous buffers: lipase B from Candida antarctica (CALB) and lipase from Candida rugosa (CRL-OF) immobilized on the Octyl-Sepharose CL-4B carrier. As part of the optimization conditions of the immobilization, the influence of time on the catalytic activity and lipase loading, as well as the effect of temperature on lipase activity (optimal incubation—14 h at 4 °C), was determined. The thermal stability test procedure was carried out for 7 days using a climatic chamber (65 °C) and a refrigerator (4 °C). The studies of immobilized lipases included the assessment of the impact of various solvents (water, citrate buffer, 1,2-dichloropropane—DCP), temperature, light in the visible spectral range (400–800 nm), and additions of calcium ions. The highest value of residual activity (564.5 ± 21.6%) was received by storing the immobilized CALB in citrate buffer (pH 4.0, 500 mM) with the addition of calcium ions (Ca2+). On the other hand, residual activity values for immobilized CRL-OF after storage in the climatic chamber were lower than 5%. A combining of techniques: immobilization onto the support in high ionic strength and low pH, with a technique of extremally high-temperature applied in a climatic chamber, with the addition of Ca2+ allowed to achieve of excellent thermal stability of the immobilized CALB, with increasing of catalytic activity more than five-fold. Additionally, performing studies on the thermal stability of the tested lipases using a climatic chamber seems to be particularly promising in the context of unifying and standardizing storage guidelines, enabling the comparison of results between different laboratories, as well as enhancing catalytic activity.

3 August 2022 in Catalysts
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Journal Article
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Tomasz SiódmiakTomasz Siódmiak
Tomasz Siódmiak
JDJacek Dulęba
Jacek Dulęba
NKNatalia Kocot
Natalia Kocot
DWDorota Watrobska-Swietlikowska
Dorota Watrobska-Swietlikowska
MMMichał Piotr Marszałł
Michał Piotr Marszałł
Lipase Amano A from Aspergillus niger (AA-ANL) is among the most commonly applied enzymes in biocatalysis processes, making it a significant scientific subject in the pharmaceutical and medical disciplines. In this study, we investigated the lipolytic activity of AA-ANL immobilized onto polyacrylic support IB-150A in 23 oils of natural origin containing various amounts of polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs). The created systems were expressed as an ‘ESS catalytic triangle’. A distinct ‘jump’ (up to 2400%) of lipolytic activity of immobilized AA-ANL compared to free lipase and hyperactivation in mostly tested substrates was observed. There was a ‘cutoff limit’ in a quantitative mutual ratio of ω-PUFAs/MUFAs, for which there was an increase or decrease in the activity of the immobilized AA-ANL. In addition, we observed the beneficial effect of immobilization using three polyacrylic supports (IB-150A, IB-D152, and IB-EC1) characterized by different intramolecular interactions. The developed substrate systems demonstrated considerable hyperactivation of immobilized AA-ANL. Moreover, a ‘lipolytic jump’ in the full range of tested temperature and pH was also observed. The considerable activity of AA-ANL-IB-150A after four reuse cycles was demonstrated. On the other hand, we observed an essential decrease in stability of immobilized lipase after 168 h of storage in a climate chamber. The tested kinetic profile of immobilized AA-ANL confirmed the decreased affinity to the substrate relative to lipase in the free form.

28 February 2023 in Catalysts
Verified
Journal Article
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Tomasz SiódmiakTomasz Siódmiak
Tomasz Siódmiak
JSJoanna Siódmiak
Joanna Siódmiak
RMRafał Mastalerz
Rafał Mastalerz
NKNatalia Kocot
Natalia Kocot
JDJacek Dulęba
Jacek Dulęba
MMMichał Piotr Marszałł
Michał Piotr Marszałł
The application of the climatic chamber presented in this paper to assess the storage stability of immobilized lipases is a new approach characterized by the potential of unifying the study conditions of biocatalysts created in various laboratories. The data achieved from storing lipases in the climatic chambers may be crucial for the chemical and pharmaceutical industry. Our paper describes the developed protocols for immobilization via interfacial activation of lipase B from Candida antarctica (CALB) and lipase OF from Candida rugosa (CRL-OF) on the Octyl-Sepharose CL-4B support. Optimization included buffers with different pH values of 4–9 and a wide range of ionic strength from 5 mM to 700 mM. It has been shown that the optimal medium for the CALB immobilization process on the tested support is a citrate buffer at pH 4 and high ionic strength of 500 mM. Implementing new optimal procedures enabled the hyperactivation of immobilized CALB (recovery activity 116.10 ± 1.70%) under the applicable reaction conditions using olive oil as a substrate. Importantly, CALB storage stability tests performed in a climatic chamber under drastic temperature and humidity conditions proved good stability of the developed biocatalyst (residual activity 218 ± 7.3% of dry form, after 7 days). At the same time, the low storage stability of CRL OF in a climatic chamber was demonstrated. It should be emphasized that the use of a climatic chamber to test the storage stability of a dry form of the studied lipases immobilized on Octyl-Sepharose CL-4B is, to our knowledge, described for the first time in the literature.