Studies on the Synthesis of Unusual Amino Acids and their incorporation into new Peptide Antibiotics

As microorganisms continue to develop resistance and survive against many different forms of antimicrobial solutions, such as antibiotics, there is urgent need for new classes of antimicrobial peptides to mitigate the threat. Bacteria are a rich source of ribosomally-synthesized antimicrobial peptides known as bacteriocins, which are produced by one bacterial species to kill other bacterial strains. Lanthionine-containing lantibiotics and sactibiotics are post-translationally modified bacteriocins which display extremely potent antibacterial activity. Thuricin CD, a two-peptide system belonging to the sactibiotic family, shows high activity, but most importantly excellent selectivity, against C. difficile infection. The Thuricin CD peptides contain a number of highly unusual quaternary α-amino acid residues with a sulfur to α-carbon link (SAC). To synthesise these peptides, methods to introduce unusual SAC building blocks into peptide structure are required. Therefore, the first aim of this research was to synthesise quaternary α-amino acid residues with a sulfur to α-carbon link. A well-studied lantibiotic, nisin, which has a polycyclic peptide structure of 34 amino acids, is currently used worldwide as a food preservative in dairy, meat and tinned-food products. It is an antimicrobial agent against Gram-positive bacteria, but is unstable at physiological pH, in part due to the reactive dehydroalanine residue at position 5 in the A ring. Development of nisin analogues with increased stability, while also maintaining high bioactivity, would greatly enhance the possible use of a nisin analogue as a theraputic agent. The next project aim was to synthesise an analogue of the A-ring of nisin by replacing Dha5 by a cyclopropyl residue (AC3C). An interesting feature of many lantibiotics is the similarity among their A-ring fragments. They contain the same number of amino acid residues, with the Dha and lanthionine (thioether link) residues present in all of the structures. The major difference between the various A-rings are the amino acids residues flanking the Dha moiety. Finally, this thesis investigates how amino acids beside Dha could affect the peptide conformation as well as its physicochemical properties

The 72-Item Semi-Quantitative Food Frequency Questionnaire (72-Item SQ-FFQ) for Polish Young Adults: Reproducibility and Relative Validity

The food frequency questionnaires (FFQs) are the most common tools used in dietary research. Each newly developed, modified, or adapted FFQ should be validated in the target population. The aim of this study was to assess the reproducibility and relative validity of the 72-item semi-quantitative food frequency questionnaire (72-item SQ-FFQ) for Polish adults. The 72-item SQ-FFQ was developed based on a non-quantitative FFQ covering 62 food items (62-item FFQ-6®). The study was conducted among 186 university students aged 19–26 years (47.8% of females). The FFQ was administered on two occasions (FFQcrude and FFQretest) to assess the test–retest reproducibility, and the FFQcrude was compared with the estimated food record (FRcrude) to evaluate the relative validity of the FFQ in assessing the intake of energy, 38 nutrients, and alcohol. The energy intake obtained with both methods was standardized to 2000 kcal/day (FFQstand, FRstand). The dietary intake obtained with FFQcrude was adjusted using linear regression analysis (FFQreg). The reproducibility and relative validity of the FFQ were assessed by comparing the mean values of energy and nutrient intake and using Spearman’s correlation coefficient, the cross-classification analysis, and the Bland–Altman method. Spearman’s correlation coefficient between both administrations of the FFQ ranged from 0.631 to 0.878 (the intraclass correlation coefficient: 0.583–0.935), for FFQcrude and FRcrude ranged from −0.025 to 0.390, for FFQstand and FRstand ranged from 0.021 to 0.546, and for FFQreg and FRcrude ranged from 0.028 to 0.391. The percentage of respondents classified into the same or adjacent quartiles of nutrient intake obtained from two administrations of the FFQ ranged from 84.9% to 97.8%, for FFQcrude and FRcrude ranged from 61.3% to 76.9%, for FFQstand and FRstand ranged from 63.4% to 83.9%, and for FFQreg and FRcrude ranged from 60.2% to 76.9%. In conclusion, our findings showed good reproducibility and acceptable relative validity of the 72-item SQ-FFQ. This tool can be recommended for assessing dietary intake among Polish young adults. However, the intake of certain nutrients should be interpreted with caution

Badanie czynnikow warunkujacych spozycie pozywienia - preferencje pokarmowe

The preferences for three protein and six carbohydrate products were examined in young, growing, male Wistar rats. The selected products were successively excluded from the choices given to rats and the changes in preference were observed. The rats were shown to prefer carbohydrate products more than protein products. For the carbohydrate products, the intake of wheat flour and pearl barley was the highest, of corn flour and buckwheat groat the lowest. From the protein products, the rats selected most often soybean meal and the least Canola meal. The rats were able to regulate the intake regarding both the type and amount of food. The preferences for certain products changed depending on the choice offered for consumption. Over a short-term period of the experiment, no specific preferences for the vitamins supplied with corn starch were observed. The preferences for Canola meal and buckwheat groat increased after the rats had adapted to their consumption.Badaniom poddano białkowe i węglowodanowe produkty paszowe i spożywcze. W kolejnych etapach doświadczenia wytypowane produkty eliminowano obserwując zmianę preferencji na pozostałe produkty. Preferencje pokarmowe określono na młodych, rosnących szczurach szczepu Wistar, płci męskiej. Uzyskane wyniki badań dowodzą, że zwierzęta wykazywały wyższe preferencje w stosunku do produktów węglowodanowych niż produktów białkowych. Z produktów węglowodanowych najwyższe spożycie stwierdzono w przypadku mąki pszennej i kaszy jęczmiennej, zaś najniższe w przypadku mąki kukurydzianej i kaszy gryczanej. Spośród produktów białkowych szczury najchętniej wybierały śrutę sojową, natomiast w najmniejszej ilości spożywały śrutę rzepakową. Zwierzęta posiadały zdolność regulacji zarówno rodzaju, jak i ilości spożywanego pożywienia, a preferencje pokarmowe do określonych produktów zmieniały się, w zależności od zestawu pokarmów podawanych im do spożycia. Nie stwierdzono specyficznych preferencji szczurów do witamin dostarczonych z produktami. Preferencje pokarmowe zwierząt do niektórych produktów (śruta rzepakowa, kasza gryczana) wzrastały po okresie przyzwyczajenia do ich spożywania

Recent advances in the catalytic oxidation of alkene and alkane substrates using immobilized manganese complexes with nitrogen containing ligands

In recent years, many supported manganese catalysts for the oxidative transformations of hydrocarbons by various terminal oxidants have been designed and tested. A vast range of inorganic (e.g. silica, carbon, zeolites), organic (e.g. polymers, dendrimers), and hybrid (e.g. polymeric phosphates, metal-organic frameworks) materials have been chosen to immobilise catalysts using various anchoring and embedding methods including covalent bonding, axial coordination and non-covalent interactions. This review provides a comprehensive overview of the applications of heterogenised manganese complexes with different nitrogen containing ligands, including porphyrins, salens and amines immobilized on inorganic or/and organic supports in the catalytic oxidation of alkanes and alkenes

Evaluation of Qualitative Dietary Protocol (Diet4Hashi) Application in Dietary Counseling in Hashimoto Thyroiditis: Study Protocol of a Randomized Controlled Trial

The current state of knowledge related to diet in Hashimoto thyroiditis (HT) is far from satisfactory, as many HT subjects experience several disorders and report reduced quality of life. There are three aims of the study: (1) to develop a qualitative dietary protocol (QDP; ‘Diet4Hashi’) as a simple, graphic–text tool dedicated to TH subjects, (2) to evaluate the use of the QDP in dietetic counseling compared to conventional dietetic counseling (CDC) in HT women, and (3) to assess the impact of both the QDP and the CDC on the diet quality, quality of life, adiposity, and metabolic parameters of HT women. The QDP is based on subject self-monitoring supported with a graphic–text tool to help them in food selection and adequate food frequency consumption, while the CDC on oral explanation and printed sample menus were provided by a dietician. The QDP contains two lists: (A) foods recommended for consumption and (B) foods with limited consumption, along with indicated consumption frequency per day/week/month. Both approaches include the same dietary recommendations for HT extracted from the literature but differ in subject–dietician cooperation. To summarize the evidence regarding dietary recommendations in HT, the PubMed, Embase, and Cochrane Library databases (to March 2019) and the bibliographies of key articles were searched. The study is designed as a dietary intervention lasting six months in two parallel groups: experimental and control. In the experimental group, the QDP will be applied, while in the control group, the CDC will be applied. In total, the study will include a baseline of 100 women with diagnosed HT. The subjects will be randomly allocated into the experimental/control groups (50/50). Data related to diet quality and other lifestyle factors, nutrition knowledge, quality of life, thyroid function, body composition, blood pressure, serum fasting glucose, and lipid profile at baseline and after a six-month follow-up will be collected. This study was conducted to develop a dietary protocol (Diet4Hashi) that is easy to follow for HT subjects, and it will contribute to providing valuable data that are useful to dieticians and physicians. It is anticipated that this graphic–text qualitative dietary protocol, by improving food selection and diet quality, may reduce adiposity and improve metabolic parameters and the quality of life of HT women

Dietary fiber sources consumption and overweight among Polish male students. A cross-sectional study

Background. There has been an increase in the prevalence of overweight and obesity in adolescents and young adults, especially in men than women. Many adolescents have a sedentary lifestyle and consume more processed, low-fiber foods. Objective. The aim of this study was to assess the frequency of fiber intake and its selected dietary source consumption in relation to the overweight among Polish male students. Material and Methods. This cross-sectional study involved 1,233 male students aged 13.0-24.9 years from northern, eastern and central Poland. The respondents completed a self-administered Block Screening Questionnaire for Fruit/Vegetable/ Fiber Intake and measurements of their body mass and height were performed. The overweight and obesity prevalence was assessed using international standards. Results. The most frequently consumed foods by students included: white bread and potatoes, fruit and fruit or vegetable juices. The odds of overweight (including obesity) were lower from 28% (OR=0.72; 95%CI:0.56-0.93) to 31% (OR=0.69; 95%CI:0.50-0.95) with a daily consumption of white bread compared to non-daily consumption of white bread. Consumption ≥4 times/week of prepared vegetables (cooked, preserved or marinated) was associated with 51% lower odds of overweight (OR=0.49; 95%CI:0.27-0.97) compared to consumption less than 4 times/week of these foods. The odds of overweight for the level of fiber intake was insignificant. Conclusions. This study provides surprising insights regarding high-fiber and low-fiber food consumption and overweight in Polish male students. A lower odds of overweight was associated with a higher frequency consumption of relatively low in fiber foods as white bread and cooked, preserved or marinated vegetables. Most of the students consumed fiber at an unacceptable level, so a beneficial impact of high-fiber foods on overweight prevalence was not shown.Wprowadzenie. Obserwuje się wzrost częstości występowania nadwagi i otyłości u młodzieży i młodych osób dorosłych, zwłaszcza u mężczyzn niż kobiet. Wielu nastolatków prowadzi siedzący tryb życia i spożywa wysoko przetworzoną, ubogą w błonnik żywność. Cel. Celem badań była ocena częstotliwości spożycia błonnika i wybranych, pokarmowych źródeł błonnika w relacji do występowania nadwagi u Polskich uczniów i studentów płci męskiej. Materiał i metody. Badania przekrojowe obejmowały 1 233 uczniów i studentów płci męskiej w wieku 13,0-24,9 lat z północnej, wschodniej i centralnej Polski. Respondenci wypełnili samozwrotny kwestionariusz Block (Screening Questionnaire for Fruit/Vegetable/Fiber Intake). Wykonano pomiary masy i wysokości ciała u każdego z badanych. Oceny występowania nadwagi i otyłości dokonano z wykorzystaniem międzynarodowych standardów. Wyniki. Do najczęściej spożywanych przez respondentów należały: biały chleb, ziemniaki, owoce, owocowe lub warzywne soki. Iloraz szans występowania nadwagi (w tym otyłości) był niższy o 28% (OR=0,72; 95%CI:0,56-0,93) do 31% (OR=0,69; 95%CI:0,50-0,95) u osób codziennie spożywających białe pieczywo w porównaniu z osobami, które nie spożywały codziennie białego pieczywa. Spożycie 4 razy w tygodniu lub częściej przetworzonych warzyw (gotowanych, konserwowanych lub marynowanych) było związane z 51% niższym ilorazem szans występowania nadwagi (OR=0,49; 95%CI:0,27-0,97) w porównaniu z rzadszym spożyciem tej żywności. Iloraz szans występowania nadwagi dla poziomu spożycia błonnika nie był istotny. Wnioski. Badanie dostarcza zaskakujących spostrzeżeń dotyczących spożycia żywności o wysokiej i niskiej zawartości błonnika i występowania nadwagi u Polskich uczniów i studentów płci męskiej. Niski iloraz szans występowania nadwagi był związany z częstszym spożyciem żywności o stosunkowo niskiej zawartości błonnika, takiej jak białe pieczywo i gotowane, konserwowane lub marynowane warzywa. Większość badanych uczniów i studentów spożywała błonnik na niewystarczającym poziomie, zatem nie odnotowano korzystnego wpływu spożycia żywności wysoko błonnikowej na występowanie nadwagi