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    D-optimal experimental design for production models in nonstandard experiments
    (Wiley, 2020) Ozdemir, Akin
    Robust design is an effective Quality by Design method to reduce product variation by selecting levels of design factors. For a number of situations, a nonstandard design region with linearly limited resources is needed to conduct an experiment. In the literature, little attention has been given to the development of robust design models for the nonstandard design region with a combination of linearly limited resources and a limited number of design points. In this paper, a selection scheme of D-optimal experimental design points is proposed to generate design points using the modified exchange algorithm for the nonstandard design region while specifying linearly limited resources and the limited number of design points. The modified exchange algorithm is able to generate global design points with less time complexity than the improved Fedorov algorithm. In addition, robust design models linking a D-optimal experimental design with quality considerations are proposed in order to obtain optimum settings of design factors for the product. Comparative studies are also presented. Finally, a real-life experimental study shows that the proposed models with the desirability function and the sequential quadratic programming technique achieve greater variance reduction than the traditional counterparts.
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    Development of a Fuzzy Exponentially Weighted Moving Average Control Chart with an ?-level Cut for Monitoring a Production Process
    (Springer Heidelberg, 2021) Goztok, Kader Kaplan; Ucurum, Metin; Ozdemir, Akin
    Statistical quality control is a useful approach that applies to statistical techniques for monitoring a production system. These charts are effective to monitor the process under certain conditions. On the other hand, the fuzzy set theory is an appropriate tool to deal with an uncertain situation. This paper is fourfold. First of all, triangular fuzzy numbers with an alpha-level cut technique are used for each sample. The alpha-level cut technique is sensitive to satisfy the process requirement. Second, a fuzzy exponentially weighted moving average (FEWMA) control chart is proposed with the alpha-level cut technique. The proposed FEWMA detects small shifts under uncertain situations while using a unity technique for samples. Third, the fuzzy target-focused process capability index (FCpm) index is proposed to measure the fuzzy process performance. Then, a case study is presented to monitor a pumice block plant using the FEWMA control chart with the alpha-level cut and measure the process performance with the FCpm index. Comparative studies are also presented. By using the proposed FEWMA control chart with the alpha-level cut, the accuracy and the flexibility of control specification limits are reported for the case study.
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    Effective biocatalytic synthesis of enentiopure ( R )-1,2-diphenylethanol as a pharmaceutical precursor using whole-cell biocatalyst
    (Elsevier, 2024) Cakmak, Fadile; Ozdemir, Akin; Dertli, Enes; Sahin, Engin
    Optically active alcohols are crucial precursors. 1,2-Diarylethanols and their analogues constitute a significant group of substances of biological significance. The biocatalytic synthesis of ( R )-1,2-diphenylethanol ( ( R )-2 ), which can be utilized as a precursor to important drugs, is still not at the desired level in terms of substrate amount and production process. This study asymmetrically reduced 1,2-diphenylethanone (1) using the Lactobacillus paracasei BD87E6 biocatalyst and a novel orthogonal quadratic design -embedded optimization approach. The following reaction optimization conditions were determined using the suggested optimization technique: pH = 6, temperature = 31 C-degrees , incubation period = 48 h, and agitation speed=134 rpm. In addition, the reaction conversion was estimated to be 99.38 %, and the product 's enantiomeric excess (ee) was estimated to be 99.12 %. Further, ( R )-2 was produced with >99 % ee, >99 % conversion, and 98 % yield in the experimental investigation under the established optimum conditions. This study is the first attempt to reduce substrate 1 to (R) or (S)-2 using a mathematical optimization method in the presence of a biocatalyst. Furthermore, on a highgram scale, 1 (15.70 g) was entirely transformed into ( R )-2 (15.54 g, 98 % isolated yield). Notably, this study is also the first to perform the gram -scale production of ( R )-2 using a novel optimization approach and a biocatalyst. Finally, the innovative and novel orthogonal quadratic design -embedded optimization technique has been demonstrated as an efficient, cost-effective, and environmentally friendly biocatalytic procedure for synthesizing ( R )-2 .
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    Efficient bio-catalytic production of enentiopure (S)-(4-chlorophenyl) (phenyl)methanol as a drug precursor by using a novel rotatable composite design-based optimization strategy
    (Elsevier, 2023) Tozlu, Nesrullah; Bulbul, Ali Savas; Ozdemir, Akin; Sahin, Engin
    Asymmetric bioreductions catalyzed by biocatalysts have demonstrated great promise in manufacturing chiral alcohols. On the other hand, the synthesis of (S)-(4-chlorophenyl)(phenyl)methanol ((S)-2), precursors of Lcloprastine and carbinoxamine, still presents considerable challenges due to the inadequate substrate quantity and production process. In this work, a novel rotatable composite design-based optimization technique was used with the Lactobacillus paracasei BD101 biocatalyst for the asymmetric reduction of (4-chlorophenyl)(phenyl) methanone (1). Optimization conditions of the reaction were determined by the proposed optimization strategy as: pH=5.85, temperature=37 degrees C, incubation time=71 h, and agitation speed=120 rpm. The reaction conversion and the product of enantiomeric excess (ee) were also predicted to be 97% and 99%, respectively. In the experimental study performed under the determined optimized conditions, (S)-2 was obtained with >99% ee, >99% conversion, and 97% yield. In addition, 1 with the amount of 15.166 g was completely converted to (S)-2 (14.85 g, 97% isolated yield) on a high-gram scale. Notice that the manufacture of (S)-2 on a gram scale utilizing a biocatalyst and an optimization technique is demonstrated in this work for the first time. Finally, an economical, effective, and environmentally friendly biocatalytic process for the biocatalytic synthesis of (S)-2, which have antitussive and antiemetic properties and relax the bronchial muscle, has been demonstrated by the novel rotatable composite design-based optimization method.
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    Efficient bioreduction of 4-phenyl-2-butanone to drug precursor (S)-4-phenyl-2-butanol by a whole-cell biocatalyst using a novel hybrid design technique
    (Elsevier, 2024) Bayhan, Beyzanur; Ozdemir, Akin; Dertli, Enes; Sahin, Engin
    Asymmetric synthesis is a critical tactic in pharmaceutical industries for creating chiral medications as it allows an enantiomer to be obtained in synthetic chemistry. The asymmetric bioreduction processes by biocatalysts have shown significant potential in producing chiral alcohols. The amount of substrate and the production method of the biocatalytic synthesis of (S)-4-phenyl-2-butanol ((S)-2) are not still desired levels. Furthermore, the biocatalytic asymmetric reduction of 4-phenyl-2-butanone (1) to (R)- or (S)-4-phenyl-2-butanol did not use any mathematical modeling techniques. In this study, the asymmetric bioreduction of 1 was carried out in this work employing Lactobacillus paracasei BD71 biocatalyst and a novel hybrid design-based optimization approach. By using the hybrid design technique, the optimal circumstances were discovered to be pH = 7, temperature = 29 degrees C, incubation period = 66 h, and agitation speed = 189 rpm. Also, the enantiomeric excess (ee) and conversion could be 99.15 % and 98.19 %, respectively. Next, (S)-2 was acquired to be ee: 99 %, conversion: >99 %, and yield: 97 % from the optimum bioreduction conditions. Furthermore, 14.08 g of 1 under optimal conditions was entirely transformed into (S)-2 (13.84 g, 97 % isolated yield). This study is the first research attempt to use a biocatalyst and an innovative and new hybrid design-based optimization approach to fabricate enantiopure (S)-2 at a high gram scale. This work has successfully demonstrated that the new hybrid design-based optimization technique is applicable to biocatalytic asymmetric reduction processes.
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    Efficient bioreduction of cyclohexyl phenyl ketone by Leuconostoc pseudomesenteroides N13 biocatalyst using a distance-based design-focused optimization model
    (Elsevier, 2022) Ozdemir, Akin; Sahin, Engin
    Whole-cell biocatalysts have been a popular method for the preparation of chiral alcohols. Although asymmetric reduction of cyclohexyl(phenyl)methanone (1) by chemical catalysts is common, a biocatalytic asymmetric reduction is extremely rare. In this respect, we report herein that Leuconostoc pseudomesenteroides N13 was successfully employed as a biocatalyst to reduce 1 to (S)-cyclohexyl(phenyl)methanol ((S)-2). Furthermore, the use of a mathematical optimization strategy for asymmetric reduction of substrate 1 is not known in the current literature. The new distance-based design-focused optimization model was used to enhance the conversion of the substrate, enantiomeric excess (ee) of product, and yield. The distance-based design-focused optimization model identified the following optimal bioreduction conditions: pH=6.46, temperature=30 degrees C, incubation period=72 hours, and agitation speed=199 rpm. Then it was stated that under these ideal conditions, (S)-2 may be produced with 99 % ee and 98.46 % conversion rate (cr). (S)-2 was achieved with 99% ee, and 99% cr as a consequence of the experimental reaction carried out under the indicated optimization conditions. It has been shown that Leuconostoc pseudomesenteroides N13 can be utilized as a biocatalyst in asymmetric reduction reactions. This study, in addition to being the first example of a bioreduction of substrate 1 by mathematical optimization, also demonstrates for the first time the distance-based design-focused model can be used in the bioreduction reaction.
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    An I-optimal experimental design-embedded nonlinear lexicographic goal programming model for optimization of controllable design factors
    (Taylor & Francis Ltd, 2021) Ozdemir, Akin
    Optimal experimental designs are effective offline quality improvement techniques used to enhance existing products and develop new products for a constrained design region. For some practical situations, I-optimal experimental designs may be the most suitable way to construct optimal experimental design points, by addressing prediction variance to generate a measure of prediction performance over the non-standard experimental design region. The purpose of this article is three-fold: (1) the I-optimality criterion is selected for minimizing the average prediction variance; (2) fitted mean and variance response models are found; and (3) a nonlinear lexicographic goal programming model incorporating an I-optimal experimental design is proposed to find the optimum settings of controllable design factors. Comparison studies and a numerical example are provided to illustrate the effectiveness of the proposed methodology for improvement of the quality of products.
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    Modeling design parameters with Taguchi experimental method for obtaining operating conditions for Cu(II) removal through adsorption process
    (Desalination Publ, 2019) Serencam, Huseyin; Ozdemir, Akin; Teke, Cagatay; Ucurum, Metin
    One of the environmental concerns deals with the removal process of pollutants in water and wastewater. In this paper, a removal process was used to eliminate pollutants in water and wastewater. The aim of this paper was to obtain an optimum adsorption condition for the highest metal ions adsorbed (MIA) mg/g. For this particular purpose, a Taguchi L-18 design was conducted. In addition, the signal-to-noise ratio was analyzed for optimum adsorption levels. The analysis of variance was also performed to evaluate the effect of each adsorption condition on MIA (mg/g) values. Moreover, an optimization model was also proposed to find the best optimal setting of adsorption levels. Then, the confirmation tests were performed using optimum coded levels of the adsorption parameters for the verification purpose. The results of the experimental study showed a good performance that Cu(II) removal capacity was found to be 43.66 mg/g. To the best of our knowledge, this research is the first to study natural stone as an efficient, inexpensive and cheap adsorbent for the removal process.
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    Modified distance optimization method for the asymmetric bioreduction conditions of phenyl(thiophen-2-yl)methanone by Weissella paramesenteroides N7
    (Pergamon-Elsevier Science Ltd, 2023) Ozdemir, Akin; Sahin, Engin
    Chirality plays a significant part in life since it is closely linked to carrying out the many metabolic processes that make up a living being. Chiral secondary alcohols such as diaryl-, aryl heteroaryl-, and diheteroaryl are employed in pharmaceuticals as drug intermediates. Although biocatalytic asymmetric reduction of prochiral ketones containing aromatic and heteroaromatic groups is widely known, biocatalytic reduction of heteroaromatic prochiral ketones containing sulfur heteroatoms is rarely known. Very few studies exist in the literature, including the biocatalytic reduction of phenyl(thiophen-2-yl) methanone (1). Moreover, the biocatalytic reduction of 1 with a mathematical modelling and optimization technique is unknown until now. In this study, Weissella paramesenteroides N7 biocatalyst for the asymmetric bioreduction of 1 using a novel modified distance optimization method. Optimization conditions were found as pH = 6.46, temperature = 26 degrees C, incubation period = 71 h, agitation speed = 200 rpm by the modified distance optimization method, and it was determined that the conversion and enantiomeric excess (ee) under these conditions could be 98.7% and 98%, respectively. Under these proposed optimization conditions, (S)-phenyl(thiophen-2-yl)methanol ((S)-2) was obtained with >99% ee, >99% conversion, and 97% yield. In addition, 11.29 g of 1 was completely converted into (S)-2 (11.07 g, 97% isolated yield) under optimized conditions. This is the first report about the fabrication of enantiopure (S)-2 in high gram scale using a biocatalyst and a novel modified distance optimization technique. In this study, the successful applicability of the new modified distance optimization method in biocatalytic asymmetric reduction reactions has been successfully demonstrated. (c) 2023 Elsevier Ltd. All rights reserved.
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    A Multi-response Nonlinear Programming Model with an Inscribed Design to Optimize Bioreduction Conditions of (S)-phenyl (pyridin-2-yl)methanol by Leuconostoc pseudomesenteroides N13
    (Springer Heidelberg, 2024) Ozdemir, Akin; Sahin, Engin
    Asymmetric bioreductions have the potential to synthesize chiral alcohols when catalyzed by biocatalysts. Nevertheless, the (S)-phenyl (pyridin-2-yl)methanol ((S)-2) analgesic synthesis poses significant challenges concerning unsatisfactory substrate amount and production method. Thus, this study proposes an inscribed design-focused multi-response nonlinear optimization model for the asymmetric reduction of the phenyl(pyridin-2-yl)methanone (1) with Leuconostoc pseudomesenteroides N13 biocatalyst. From the novel inscribed design-focused multi-response nonlinear optimization model, optimization conditions of the reaction, such as pH = 6, temperature = 29 degrees C, incubation time = 53 h, and agitation speed = 153 rpm, were found. Also, the reaction conversion was predicted to be 99%, and the product of the enantiomeric excess (ee) was 98.4% under the obtained optimization conditions. (S)-2 was obtained with 99% ee, 99% conversion, and 98% yield while performing a validation experiment using the determined optimized conditions. In addition, 1 with the amount of 11.9 g was converted entirely to (S)-2 (11.79 g, 98% isolated yield) on a high gram scale. Also, this study is noted as the first example of the gram-scale production of (S)-2 using an optimization strategy and biocatalyst. Further, the applicability of the inscribed design-focused optimization model in biocatalytic reactions has been demonstrated and provides an effective process for the analgesic synthesis of (S)-2, which is a green, cost-effective method of producing chiral aryl heteroaryl methanol.
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    A novel approach to finding optimum operating conditions of design factors for the grinding experiment
    (Taylor & Francis Inc, 2021) Ucurum, Metin; Ozdemir, Akin; Teke, Cagatay; Tekin, Ilker
    The efficiency of grinding experiments is an important issue for many industries. In this paper, a central composite design-based methodology was proposed to investigate the four design factors that affect the particle sizes. The four design factors were specified as mill speed (% of N-c ), ball filling ratio (f(c) ), powder filling ratio (j(b) ) and grinding time (min). Another important issue was how to obtain an optimum operating condition for four design factors. For this particular purpose, a novel dual response optimization model was proposed using the particle sizes (d (10), d (50), and d (90)) and the span value concept. This proposed approach was compared to the desirability function-based optimization concept. The verification study of the experiment was also carried out. The results of the grinding experiment runs showed that the optimum operating conditions were mill speed 73.495% of N-c , ball filling ratio 0.354, powder filling ratio 0.157, and grinding time 70 min. In addition, d (10), d (50), and d (90) were found 3.31 mu m, 12 mu m, and 45.6 mu m, respectively. The span value was also found at 3.52.
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    A Novel Fuzzy Cumulative Sum Control Chart with an ?-Level Cut Based on Trapezoidal Fuzzy Numbers for a Real Case Application
    (Springer Heidelberg, 2024) Ozdemir, Akin; Ucurum, Metin; Serencam, Hueseyin
    Statistical process control (SPC) is widely used to monitor production processes in many industries under certain conditions. When dealing with a quality characteristic for uncertainty, fuzzy numbers are used in the context of the statistical process control (SPC) to monitor a fuzzy production process. The aim of this paper is fourfold. One, a fuzzy X-R control chart with an alpha-level cut is used based on trapezoidal fuzzy numbers (TFNs) for detecting the large shifts in the fuzzy process mean. Second, a fuzzy cumulative sum (FCUSUM) control with an alpha-level cut based on TFNs is firstly developed for detecting the small shifts in the fuzzy process mean. Third, the fuzzy process capability indices (FPCIs) are presented to measure the fuzzy process performance. Finally, an ultra-fine calcite production process is controlled with both the fuzzy X-R control chart and the proposed FCUSUM control chart. The results of the fuzzy X-R control charts show that the fuzzy production process is in control, and large shifts in the fuzzy process mean were detected. On the other hand, the results of the FCUSUM charts show that the fuzzy production process is out of control, and small shifts in the fuzzy process mean were detected. FPCIs are also conducted, and the results of fuzzy C-pk indices show that the ultra-fine calcite production process is not capable of meeting specification limits.
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    A novel weighted mean-squared error optimization model to obtain optimal conditions of adsorption factors for a lead removal process
    (Desalination Publ, 2021) Ozdemir, Akin; Teke, Cagatay; Serencam, Huseyin; Ucurum, Metin; Gundogdu, Ali
    Lead (Pb) removal process from wastewater is an important issue to prevent health problems for people. For this particular purpose, a low-cost adsorbent may be beneficial for improving the adsorption capacity for the Pb removal process. The aims of this paper are four-fold. First of all, a D-optimal experimental design was selected to reduce experimental runs and its cost. Second, the effect of four adsorption design factors, stirring speed (rpm), adsorbent dosage (g), pH level, and initial metal concentration (ppm), was examined. Also, the yellow natural stone, which is from Bayburt, Turkey, was used as a cheap adsorbent for the Pb removal process from the solution. Third, a novel weighted mean-squared error optimization model was developed to obtain optimal adsorption levels for adsorption factors. Besides, a verification study was conducted to verify the results of the adsorption experiment. Finally, the lead (Pb( II)) removal capacity of the yellow Bayburt stone was obtained to be 46.031 mg/g, and the results of the experiment from the proposed methodology showed a good performance for the removal study.
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    Optimization of asymmetric bioreduction conditions of 1-(thiophen-2-yl)ethanone by Weissella cibaria N9 using a desirability function-embedded face-centered optimization model
    (Taylor & Francis Inc, 2023) Bolubaid, Mohammed; Ozdemir, Akin; Dertli, Enes; Alamoudi, Mohammed; Taylan, Osman; Karaboga, Dervis; Yilmaz, Mustafa Tahsin
    Prochiral ketones can be effectively bio-reduced to chiral secondary alcohols by whole-cell biocatalysts, which are possible useful precursors to synthesize physiologically active chemicals and natural products. When whole-cell biocatalysts strains are used, bioreduction process can be influenced by various cultural factors, and it is vital to optimize these factors that affect selectivity, conversion rate, and yield. In this study, Weissella cibaria N9 was used as whole-cell biocatalyst for bioreduction of 1-(thiophen-2-yl)ethanone, and cultural design factors were optimized using a desirability function-embedded face-centered optimization model. For this, effects of pH (4.5-5.5-6.5, x(1)), (2) temperature (25-30-35 degrees C, x(2)), (3) incubation period (24-48-72 h, x(3)), and (4) agitation speed (100-150-200 rpm, x(4)) on two response variables; (1) ee (%) and (2) cr (%) were tested. Next, desirability function-embedded face-centered optimization model revealed that a pH of 6.43, a temperature of 26.04 degrees C, an incubation period of 52.41 h, and an agitation speed of 150 rpm were the optimum levels and the estimated ee and cr responses were 99.31% and 98.16%, respectively. Importantly, the actual experimental ee and cr responses were similar to the estimated values indicating the capability of the offered desirability function-embedded face-centered optimization model when using the optimum cultural conditions.
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    Optimization of asymmetric bioreduction conditions of 1-indanone by Leuconostoc mesenteroides N6 using a face-centered design-based multi-objective optimization model
    (Taylor & Francis Inc, 2024) Alamoudi, Mohammed; Ozdemir, Akin; Dertli, Enes; Bolubaid, Mohammed; Alidrisi, Hassan M.; Taylan, Osman; Yilmaz, Mustafa Tahsin
    There has been an increasing interest in biocatalysts over the past few decades in order to obtain high efficiency, high yield, and environmentally benign procedures aiming at the manufacture of pharmacologically relevant chemicals. Lactic Acid Bacteria (LAB), a microbial group, can be employed as biocatalysts while performing asymmetric reduction of prochiral ketones. In this study, Leuconostoc mesenteroides N6 was used for the asymmetric bioreduction 1-indanone. And then, a novel and innovative face-centered design-based multi-objective optimization model was used to optimize experimental conditions. Also, the experimental design factors were defined as agitation speed, incubation period, pH, and temperature for optimization to acquire the maximum enantiomeric excess (ee) and conversion rate (cr) values. When using the face-centered design-based multi-objective optimization model, the optimum culture conditions corresponded to 96.34 and 99.42%, ee and cr responses, respectively, were pH = 5.87, incubation temperature = 35 degrees C, incubation period = 50.88 h, and agitation speed = 152.60 rpm. Notably, the validation experiment under the optimum model conditions confirmed the model results. This study demonstrated the importance of the optimization and the efficiency of the face-centered design-based multi-objective model.
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    Optimization of Asymmetric Bioreduction Conditions of 2-methyl-1-phenylpropan-1-one by Lactobacillus fermentum BY35 Using I-Optimal Design-Based Model
    (Springer Heidelberg, 2022) Aksuoglu, Selmani; Ozdemir, Akin; Serencam, Huseyin; Dertli, Enes; Sahin, Engin
    The bioreduction of prochiral ketones offers efficient access to chiral secondary alcohols, which are potentially beneficial precursors for producing many biologically active compounds and natural products. This bioreduction process can be affected by different parameters when whole-cell of biocatalysts such as Lactic Acid Bacteria strains are applied. In this context, this paper proposed an I-optimal design-based model to optimize culture parameters such as temperature, pH, incubation period, and agitation speed for asymmetric bioreduction of 2-methyl-1-phenylpropan-1-one (1) with Lactobacillus fermentum BY35 as a biocatalyst while achieving the highest conversion rate (cr) and enantiomeric excess (ee). The optimum settings of the four culture parameters and the cr and ee values were found using the proposed optimization model as follows: pH = 6.5, temperature = 25 degrees C, incubation period = 38.5 h, agitation speed = 200 rpm, the ee value = 98.78%, and the cr value = 98.92%. After the validation of the process, the cr and ee values were found to be > 99% and > 99%, respectively, while using the optimum operating conditions from the optimization model. Thus, the results of the optimization model are consistent with the results of the validation experiment. It is also noted that this paper is the first to optimize culture parameters using the proposed I-optimal design-based model for an asymmetric reduction.
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    Optimization of asymmetric reduction conditions of 1-(benzo [d] [1,3] dioxol-5-yl) ethanone by Lactobacillus fermentum P1 using D-optimal experimental design-based model
    (Taylor & Francis Inc, 2022) Ozdemir, Akin; Dertli, Enes; Sahin, Engin
    The biocatalytic asymmetric reduction of prochiral ketones is a significant transformation in organic chemistry as chiral carbinols are biologically active molecules and may be used as precursors of many drugs. In this study, the bioreduction of 1-(benzo [d] [1,3] dioxol-5-yl) ethanone for the production of enantiomerically pure (S)-1-(1,3-benzodioxal-5-yl) ethanol was investigated using freeze-dried whole-cell of Lactobacillus fermentum P1 and the reduction conditions was optimized with a D-optimal experimental design-based optimization methodology. This is the first study using this optimization methodology in a biocatalytic asymmetric reduction. Using D-optimal experimental design-based optimization, optimum reaction conditions were predicted as pH 6.20, temperature 30 degrees C, incubation time 30 h, and agitation speed 193 rpm. For these operating conditions, it was estimated that the product could be obtained with 94% enantiomeric excess (ee) and 95% conversion rate (cr). Besides, the actual ee and cr were found to be 99% tested under optimized reaction conditions. These findings demonstrated that L. fermentum P1 as an effective biocatalyst to obtain (S)-1-(1,3-benzodioxal-5-yl) ethanol and with the D-optimal experimental design-based optimization, this product could be obtained with the 99% ee and 99% cr. Finally, the proposed mathematical optimization technique showed the applicability of the obtained results for asymmetric reduction reactions.
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    Optimization of asymmetric reduction conditions of 2-bromo-1-(naphthalen-2-yl)ethanone by Enterococcus faecium BY48 biocatalyst with A-optimal design-embedded model
    (Wiley, 2022) Ozdemir, Akin; Sahin, Engin
    Aromatic alpha-halohydrins, especially 2-haloethanols, which are a common pharmacological precursor, may be readily transformed to chiral beta-adrenergic receptor blockers. Studies including the synthesis of (S)-2-bromo-1-(naphthalen-2-yl)ethanol ((S)-2), an alpha-halohydrin, in high conversion, enantiomeric excess (ee), and yield by biocatalytic asymmetric reduction of 2-bromo-1-(naphthalen-2-yl)ethanone (1) are still insufficient. Moreover, asymmetric reduction of substrate 1 using a mathematical optimization method is not explored in the current literature. In this article, the four asymmetric bioreduction conditions, which are (1) pH, (2) temperature, (3) incubation period, and (4) agitation speed, of substrate 1 were optimized to obtain (S)-2 with A-optimal design-embedded model in the presence of Enterococcus faecium BY48. Optimum bioreduction conditions were determined by the A-optimal design-embedded model as follows: pH = 7, temperature = 25 degrees C, incubation period = 24 h, and agitation speed = 200 rpm. And then, it was suggested that (S)-2 could be obtained with 98.88% ee and 100% conversion rate (cr) under these optimum conditions. As a result of the experimental reaction performed under the optimization conditions suggested by the model, (S)-2 was obtained with 99% ee and 100% cr. The study revealed that E. faecium BY48 could be used as a biocatalyst in asymmetric reduction reactions. Also, the A-optimal design-embedded model could have the great potential to obtain the optimum asymmetric bioreduction conditions.
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    Optimization of Biocatalytic Production of Enantiopure (S)-1-(4-Methoxyphenyl) Ethanol with Lactobacillus senmaizuke Using the Box-Behnken Design-Based Model
    (Springer Heidelberg, 2022) Kavi, Mervenur; Ozdemir, Akin; Dertli, Enes; Sahin, Engin
    Enantiomerically pure (S)-1-(4-methoxyphenyl) ethanol is a significant molecule for the production of various drug intermediates. (S)-1-(4-methoxyphenyl) ethanol was synthesized from 4-methoxyacetophenone using Lactobacillus senmaizuke as a biocatalyst. In addition, optimization of experimental conditions is important to analyze the role of culture parameters for catalytic bioreduction reactions. For this particular purpose, the experimental conditions of pH, incubation period, temperature, and agitation speed were investigated with the Box-Behnken experimental design-based proposed optimization model. (S)-1-(4-methoxyphenyl) ethanol, which can be used for the synthesis of antihistamines, including diphenhydramine hydrochloride and loratadine cycloalkyl [b] indoles that have the treatment function for an allergic response, was obtained in > 99% conversion, > 99% enantiomeric excess and 96% yield with whole cells of L. senmaizukei at this optimization conditions: pH = 5.80, the temperature = 29 degrees C, incubation period = 50 h, and agitation speed = 155 rpm. The bioreduction of 4-methoxyacetophenone efficiency was importantly affected by the quadratic and linear effects of experimental design parameters. Besides, the results demonstrate the importance of design parameters for catalytic bioreduction reactions. It is also concluded that the results show the effectiveness of the Box-Behnken experimental design-based proposed model to obtain optimum operating conditions of design parameters for catalytic bioreduction reactions.
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    Optimization of mechanochemical surface modification parameters on planetary mill using an I-optimal experimental design
    (Elsevier, 2024) Ozdemir, Akin; Ucurum, Metin
    Several micro -particle -size additives and filler minerals are added to many industrial products, especially plastic, in order to reduce cost and improve mechanical properties and appearance. Also, grinding and surface modification are two fundamental properties of the filler minerals used in plastic products. Notably, Bayburt stone (BS) used as a natural raw material from Bayburt, Turkiye contains 76% SiO2 and 15% Al2O3. In this paper, the hydrophilic surface structure of micronized Bayburt stone (MBS) was made hydrophobe by mechanochemical surface modification using calcium stearate [Ca(C17H35COO)2] in a laboratory -type planetary mill. Next, the optimum conditions of the surface modification design factors, which are (1) ball filling ratio = 30.53%, (2) powder filling ratio = 10.43%, (3) mill speed = 475.91 rpm, (4) chemical dosage = 1.99% of powder, and (5) modification time = 4.83 min., were obtained using the proposed I -optimal design -focused optimization model when predicting the model parameters. In addition, a coated micronized Bayburt stone (CMBS) product with an active ratio (AR) of 99.90% and d10, d50, and d90 values of 1.32 mu m, 3.48 mu m and 9.55 mu m were achieved. Finally, particle size distribution (PSD), thermo-gravimetric and differential thermal analyzer (TG -DTA), Fourier transform infrared (FTIR), scanning electron microscope (SEM), electron dispersive spectrum (EDS), and contact angle analyses were performed on the CMBS product.