Kamfenin yüksek sıcaklıkta fotobrominasyonu

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Kamfenin (62) CCl4'ün reflüks sıcaklığında moleküler Br2 ile fotobrominasyonu düzenlenmemiş dibromürlerin (76 ve 77) oluşumu ile sonuçlandı.İzomerik dibromürlerin (76 ve 77) HBr eliminasyonu ile monobrom alkenlere (78 ve 79) gidildi.Ayrıca düzenlenmemiş bileşiklerin (76 ve 77) kromatografik materyaller içindeki izomerizasyonu dibromürü (73) kantitatif verimle tek ürün olarak verdi.Dibromür 73 t-BuOK ile ilgili monobrom 80'e yüksek verimle dönüştürüldü.Monobromür 80'in CCl4 içerisinde yüksek sıcaklık (77oC) fotobrominasyonu ardından tekrar edilen kromatografi dört tane düzenlenmemiş ürünleri (82, 83, 84 ve 85) izole etmemizi sağladı.Monobromür 80'e oda sıcaklığında bromun elektrofilik katılması yüksek verimde düzenlenmiş ürün 81'in oluşumunu verdi.Bütün ürünlerin reaksiyon mekanizmaları detaylı bir şekilde tartışıldı. Tüm yeni bileşikler spektral verilerle ve kimyasal dönüşümlerle karakterize edildi.Anahtar Kelimeler: Fotobrominasyon, Kamfenin bromlama türevleri, Kamfen brominasyonuThe photobromination of camphene (62) with molecular bromine at refluxing carbon tetrachloride resulted in the formation of nonrearanged dibromides (76 and 77).Isomeric dibromides (76 and 77) were subjected to HBr elimination to give monobrom alkenes (78 and 79).In addition, izomerization of nonrearranged compounds (76 and 77) in chromatographic materials gave as a single product, dibromide 73, quantitatively.Dibromide 73 was converted by t-BuOK to corresponding monobromo 80 in high yield.The photobromination of monobromide 80 at high temperatures (77oC) in carbon tetrachloride followed by repeated chromatography allowed us to isolate four nonrearranged products (82, 83, 84 and 85).The electrophilic addition of bromine to monobromide 80 at room temperature gave in high yield to formation of rearranged product 81.The reaction mechanism of the all products were discussed in detail. All new compounds have been characterized on the basis of spectral data and by chemical transformation.Key Words: Photobromination, Brominated derivaties of camphene, The bromination of camphen

Pročišćavanje i karakterizacija α-amilaze izolirane iz soja Anoxybacillus sp. AH1, stabilne pri visokim temperaturama i u prisutnosti detergenata

A thermostable and detergent-stable α-amylase from a newly isolated Anoxybacillus sp. AH1 was purifi ed and characterized. Maximum enzyme production (1874.8 U/mL) was obtained at 24 h of incubation. The amylase was purified by using Sephadex G-75 gel filtration, after which an 18-fold increase in specific activity and a yield of 9 % were achieved. The molecular mass of the purified enzyme was estimated at 85 kDa by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature values of the enzyme were 7.0 and 60 °C, respectively. The enzyme was highly stable in the presence of 30 % glycerol, retaining 85 % of its original activity at 60 °C within 120 min. Km and vmax values were 0.102 μmol and 0.929 μmol/min, espectively, using Lineweaver-Burk plot. The enzyme activity was increased by various detergents, but it was significantly inhibited in the presence of urea. Mg2+ and Ca2+ also significantly activated α-amylase, while Zn2+, Cu2+ and metal ion chelators ethylenediaminetetraacetic acid (EDTA) and 1,10-phenanthroline (phen) greatly inhibited the enzyme activity. α-Amylase activity was enhanced by β-mercaptoethanol (β-ME) and dithiothreitol (DTT) to a great extent, but inhibited by p-chloromercuribenzoic acid (PCMB). Iodoacetamide (IAA) and N-ethylmaleimide (NEM) had a slight, whereas phenylmethylsulfonyl fluoride (PMSF) had a strong inhibitory effect on the amylase activity.U radu je pročišćena i okarakterizirana α-amilaza, izolirana iz novootkrivenog soja bakterije Anoxybacillus sp. AH1, stabilna pri visokim temperaturama u prisutnosti detergenata. Najveća količina enzima (1874,8 U/mL) proizvedena je nakon 24 sata inkubacije. Nakon pročišćavanja amilaze gel-filtracijskom kromatografijom u koloni punjenoj gelom Sephadex G-75, specifična se aktivnost enzima povećala 18 puta, a prinos je bio 9 %. Metodom SDS-PAGE određena je molekularna masa pročišćenog enzima od 85 kDa. Optimalna je pH-vrijednost bila 7,0; a optimalna temperatura 60 °C. Enzim je bio izuzetno stabilan u prisutnosti 30 %-tnog glicerola, te je zadržao 85 % aktivnosti na 60 °C tijekom 120 min. Pomoću Lineweaver-Burkovog dijagrama utvrđeno je da je vrijednost Km amilaze bila 0,102 μmol, a vmax 0,929 μmol/min. Aktivnost se enzima povećala u prisutnosti različitih detergenata, dok se u prisutnosti uree znatno smanjila. Ioni magnezija i kalcija bitno su povećali, a ioni cinka i bakra, te kelatori metalnih iona EDTA i 1,10-fenantrolin smanjili aktivnost α-amilaze. Aktivnost se α-amilaze znatno povećala i u prisutnosti β-merkaptoetanola i ditiotreitola, no smanjila dodatkom p-kloromerkuribenzojeve kiseline. Jodoacetamid i N-etilmaleimid imali su blag, a fenilmetilsulfonil fluorid jak inhibicijski učinak na aktivnost amilaze

Comparison of real-time reverse transcriptase polymerase chain reaction (RT-PCR) and IgM and IgG antibody test for the diagnosis of SARS-CoV-2 infection

In the present study, we compared the real-time reverse-transcription polymerase chain reaction (RT-PCR) and total IgM-IgG antibody tests for diagnosis SARS-CoV-2 patients. SARS-CoV-2 patients were divided into four additional subgroups according to clinical examination, and Computed Tomography (CT) for SARS-CoV-2. Groups were included 60 mild cases, 111 moderate cases, 53 severe cases, and 105 normal cases. In a mild group, 52.5% of 60 cases were found to be male, 45.9% female, and the average age was found as 38.4 ±2.011. The positive ratio was found as 80.3% in the RT-PCR test, while 39.3% in total IgM/IgG. In a moderate group, 49.1% of 111 cases were found to be male, 50% female, and the average age was 45.05 ±1.519. The positive ratio was found as 85.7% in the RT-PCR test while 54.5% in total IgM/IgG. In a severe group, 53.7%of 53 cases were found to be male, 44.4% female, and the average age was 55.5±2.122. The positive ratio was found as 75.9% both in RT-PCR and total IgM/IgG tests. In a normal group with no involvement according to Computed Tomography (CT), 49.1%of 105 cases were found to be male, 50% female, and the average age was found as 34.8±1.391. The positive ratio was found as 95.3% in the RT-PCR test while 5.7% in total IgM/IgG. Chronic diseases were detected more in severe cases, suggesting that persons who have chronic diseases or decreased immunity, such as diabetes mellitus, cardiovascular diseases, hypertension, and lung disease, are at a higher risk for developing severe COVID-19 if they are infected with SARS-CoV-2. According to our results, we can suggest a higher detection sensibility in RT-PCR than in total IgM/IgG antibody test for mild, moderate and normal group, while the detection sensibility of IgM/IgG antibody increases in a severe group with bilateral diffuse involvement according to CT

Purification and Characterization of Thermostable and Detergent-Stable α-Amylase from Anoxybacillus sp. AH1

A thermostable and detergent-stable α-amylase from a newly isolated Anoxybacillus sp. AH1 was purifi ed and characterized. Maximum enzyme production (1874.8 U/mL) was obtained at 24 h of incubation. The amylase was purified by using Sephadex G-75 gel filtration, after which an 18-fold increase in specific activity and a yield of 9 % were achieved. The molecular mass of the purified enzyme was estimated at 85 kDa by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature values of the enzyme were 7.0 and 60 °C, respectively. The enzyme was highly stable in the presence of 30 % glycerol, retaining 85 % of its original activity at 60 °C within 120 min. Km and vmax values were 0.102 μmol and 0.929 μmol/min, espectively, using Lineweaver-Burk plot. The enzyme activity was increased by various detergents, but it was significantly inhibited in the presence of urea. Mg2+ and Ca2+ also significantly activated α-amylase, while Zn2+, Cu2+ and metal ion chelators ethylenediaminetetraacetic acid (EDTA) and 1,10-phenanthroline (phen) greatly inhibited the enzyme activity. α-Amylase activity was enhanced by β-mercaptoethanol (β-ME) and dithiothreitol (DTT) to a great extent, but inhibited by p-chloromercuribenzoic acid (PCMB). Iodoacetamide (IAA) and N-ethylmaleimide (NEM) had a slight, whereas phenylmethylsulfonyl fluoride (PMSF) had a strong inhibitory effect on the amylase activity

Isolation of Thermophilic Bacteria and Investigation of Their Microplastic Degradation Ability Using Polyethylene Polymers

Microplastics (MPs) pose potential public health challenges because of their widespread occurrences in all environmental compartments. While most studies have focused on the occurrence fate of microplastics in wastewater treatment systems, the biodegradation of microplastics in wastewater is generally little understood. Therefore, we used two Gram-positive and thermophilic bacteria, called strain ST3 and ST6, which were identified by morphological, biochemical, physiological, and molecular analyses, to assess the growth and biodegradation potential of two different sized (50 and 150 m) polyethylene particles. The degradation was monitored based on structural and surface morphological changes. According to 16S rRNA analyses, ST3 and ST6 were identified as Anoxybacillus flavithermus ST3 and Anoxybacillus sp. ST6, respectively. The occurrence of cracks, holes, and dimensional changes was detected by scanning electron microscopy. Moreover, critical characteristic absorption band formation and modifications were determined by Fourier transform infrared spectroscopy. In addition to these, it was found that Anoxybacillus flavithermus ST3 and Anoxybacillus sp. ST6 produced high level of alpha-Amylase. These results showed that thermophilic bacteria are capable of the biodegradation of microplastics and production of alpha-Amylase

Stereological Study on the Effect of Carnosine on of Purkinje Cells in the Cerebellum of Rats Exposed to 900 MHz Electromagnetic Field

AIM: To evaluate the impact of carnosine on Purkinje neurons in rats exposed to a 900 Mhz electromagnetic field. MATERIAL and METHODS: This study evaluated 24 rats divided into the following three different groups: a control group, a group exposed to the electromagnetic field, and a group that was injected with carnosine while being exposed to the electromagnetic field. The electromagnetic field group was exposed to a 900 Mhz electromagnetic field for an hour daily over 28 days. Thereafter, stereological analysis was performed histologically on cerebellar sections, and the number of Purkinje cells were counted. RESULTS: The electromagnetic field group had remarkably fewer Purkinje cell compared to control. The electromagnetic field group plus 20 mg of carnosine had significantly more total Purkinje cells compared to the electromagnetic field group (p<0.05). CONCLUSION: The present study showed that electromagnetic field exposure decreases the number of Purkinje cell, whereas carnosine protected the cerebellum from neural damage induced by electromagnetic field exposure