Phytochemical investigation of Striga asiatica

Corresponding author (NCNPR): Ahmed Elbermawi, [email protected]://egrove.olemiss.edu/pharm_annual_posters_2022/1006/thumbnail.jp

Novel iodine mediated carbocyclisations and hypervalent iodine(III) reagents

The first chapter focuses on the introduction of iodine mediated carbocyclisations and their applications continue to present a stimulating challenge in target- and diversity-oriented synthesis. The second chapter discusses applications and brief literature overview about classical approaches towards the syntheses of indene derivatives. Herein the syntheses of 3-iodo-1 H-indene derivatives via iodonium-promoted 5-endo-dig carbocyclisation of 2-substituted ethynylmalonates as a key starting material are described. Within this study, we were able to show that the 3-iodo-1 H-indene can be used as a synthetic platform not only for the palladium chemistry but also as a catalyst for the in situ generation of [text unavailable] hypervalent iodine reagent. Additionally, 3-iodo-1 H-indene derivatives have the potential to perform asymmetric synthesis. Third chapter demonstrates tandem iodine mediated carboannulation of the stilbene malonate derivatives via either 5-exo- or 6-endo-trig mode under basic reagents with subsequent lactonisation to structurally complex indanes and tetrahydronaphthalenes with three new stereogenic centres. In the present study, a unique stereochemistry was observed in the case of tetrahydroindenofuranones and confirmed by single crystal X-ray analysis. These cyclisations proceed exclusively with the retention of configuration to form tetrahydroindenofuranones. Both the compounds formed as a single diastereomers as judged from their 1H and 13C NMR spectrum. In fourth chapter the synthesis of novel simplified analogues of IBA by oxidation of [text unavailable] diiodoacrylic acids are described. Additionally, the ligand exchange resulted in tosylate derivative. The new reagents have been utilized in various well established oxidative transformations with superior or similar reactivity as conventional hypervalent iodine(III) reagents.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Novel iodine mediated carbocyclisations and hypervalent iodine(III) reagents

The first chapter focuses on the introduction of iodine mediated carbocyclisations and their applications continue to present a stimulating challenge in target- and diversity-oriented synthesis. The second chapter discusses applications and brief literature overview about classical approaches towards the syntheses of indene derivatives. Herein the syntheses of 3-iodo-1 H-indene derivatives via iodonium-promoted 5-endo-dig carbocyclisation of 2-substituted ethynylmalonates as a key starting material are described. Within this study, we were able to show that the 3-iodo-1 H-indene can be used as a synthetic platform not only for the palladium chemistry but also as a catalyst for the in situ generation of [text unavailable] hypervalent iodine reagent. Additionally, 3-iodo-1 H-indene derivatives have the potential to perform asymmetric synthesis. Third chapter demonstrates tandem iodine mediated carboannulation of the stilbene malonate derivatives via either 5-exo- or 6-endo-trig mode under basic reagents with subsequent lactonisation to structurally complex indanes and tetrahydronaphthalenes with three new stereogenic centres. In the present study, a unique stereochemistry was observed in the case of tetrahydroindenofuranones and confirmed by single crystal X-ray analysis. These cyclisations proceed exclusively with the retention of configuration to form tetrahydroindenofuranones. Both the compounds formed as a single diastereomers as judged from their 1H and 13C NMR spectrum. In fourth chapter the synthesis of novel simplified analogues of IBA by oxidation of [text unavailable] diiodoacrylic acids are described. Additionally, the ligand exchange resulted in tosylate derivative. The new reagents have been utilized in various well established oxidative transformations with superior or similar reactivity as conventional hypervalent iodine(III) reagents.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Exploring Difference in Gender Perceptions Towards Teacher's Motivational Behaviour in English Language Classroom

The role of a teacher is crucial for language learning specifically in English language classrooms. An important variable in this regard is the gender of students. This study investigates the impact of gender on language learning motivations of students studying at the undergraduate level in the City University of Science and IT and Institute of Management Sciences, Peshawar. Questionnaire data were collected from 175 students. The variables of the study include gender and its relationship with language attitudes and motivation. The results revealed that there exists the relationship between gender differences in variables under consideration. Female students had more expectations as compared to their male fellows. The study has useful pedagogical implications

Assessment of knowledge, skill and attitude of oncology nurses in chemotherapy administration in tertiary hospital Pakistan.

Objective: To measure the levels of nurse’s knowledge and attitude after the conduct of education session regarding chemotherapy administration and management. Methodology: This research study was conducted at two oncology units of tertiary Hospital Rawalpindi. A prepost test intervention study design was used on 35 nurses by using Verity’s tools. Results: The mean scores of knowledge were calculated by Cochran’s Q test showed that knowledge scores have significantly increased with ‘educational training’ (p value \u3c 0.001). The difference in the attitude of the nurses was not found to be statistically significant in repeated measure of ANOVA. Conclusion: The results show that knowledge is the weakest component and attitude is strongest component of oncology nurses ‘competencies in chemotherapy administration

Novel iodine mediated carbocyclisations and hypervalent iodine(III) reagents

The first chapter focuses on the introduction of iodine mediated carbocyclisations and their applications continue to present a stimulating challenge in target- and diversity-oriented synthesis. The second chapter discusses applications and brief literature overview about classical approaches towards the syntheses of indene derivatives. Herein the syntheses of 3-iodo-1 H-indene derivatives via iodonium-promoted 5-endo-dig carbocyclisation of 2-substituted ethynylmalonates as a key starting material are described. Within this study, we were able to show that the 3-iodo-1 H-indene can be used as a synthetic platform not only for the palladium chemistry but also as a catalyst for the in situ generation of [text unavailable] hypervalent iodine reagent. Additionally, 3-iodo-1 H-indene derivatives have the potential to perform asymmetric synthesis. Third chapter demonstrates tandem iodine mediated carboannulation of the stilbene malonate derivatives via either 5-exo- or 6-endo-trig mode under basic reagents with subsequent lactonisation to structurally complex indanes and tetrahydronaphthalenes with three new stereogenic centres. In the present study, a unique stereochemistry was observed in the case of tetrahydroindenofuranones and confirmed by single crystal X-ray analysis. These cyclisations proceed exclusively with the retention of configuration to form tetrahydroindenofuranones. Both the compounds formed as a single diastereomers as judged from their 1H and 13C NMR spectrum. In fourth chapter the synthesis of novel simplified analogues of IBA by oxidation of [text unavailable] diiodoacrylic acids are described. Additionally, the ligand exchange resulted in tosylate derivative. The new reagents have been utilized in various well established oxidative transformations with superior or similar reactivity as conventional hypervalent iodine(III) reagents

Ellagic acid and Flavonoid-based Metabolites from the Seed Kernel of Irvingia gabonensis

Irvingia gabonensis (Aubry-Lecomte ex O’Rorke) Baill (Irvingiaceae), commonly known as African mango is a multipurpose tree providing food, medicine, and timber. Native to West and Central Africa, it is grown in various tropical and subtropical regions of the world. The seed kernel is of economic importance due to its popularity in local and international trade. It has now become a popular herbal weight-loss supplement, particularly in the United States. Seventeen compounds of diverse classes including four flavonoid glycosides, five ellagic acid derivatives, and eight other metabolites were isolated from the methanolic extract of the defatted seed kernel of Irvingia gabonensis. Among the isolates, quercetin 3-O-methyl-4′-[α-L-rhamnopyranosyl-(1→3)]-O-α-L-rhamnopyranoside (1) and 3,3′-di-O-methyl-4′-O-α-L-rhamnopyranosylellagic acid 4-sulfate ester (2) were found to be previously undescribed. Structure elucidation was mainly based on 1D- and 2D-NMR and HRESIMS data. The isolated compounds could be used as markers for authentication and standardization of Irvingia gabonensis commercial preparations.https://egrove.olemiss.edu/pharm_annual_posters_2024/1012/thumbnail.jp