Phytochemistry And Bioactivity Of Natural Products And Synthesis Of Silver Nanoparticles And A Novel MXene Nanohybrid Composite Material

This dissertation deals with phytochemical,bioactivities,and antioxidant studies on indigenous medicinal plants;M.royleanus（Celastraceae）（1）,synthesis of silver nanoparticles（Ag·NPs）from P.lanceolata（2）,and synthesis of a novel nanohybrid composite material（Ag NPs@MXene）from Ag·NPs with MXene（3）.Medicinal plants（MPs）have been recognized since antiquity as possessing biological activities;chief amongst these is their antibacterial,antifungal,and antioxidant properties.In this study,the chemical composition,antimicrobial,and in vitro antioxidant bioactivities of the natural products（NP）extracted by hydro distillation from MPs members of the plant are demonstrated.These activities were also demonstrated for Ag·NPs and Ag NPs@MXene.MPs play a vital role in several forms of medication;Folk medicines are become tremendously crucial in developing a therapy for human health around the world.NP isolated from MPs remained essential as medicine in human history,and numerous fatal and complicated diseases like malaria,cancer,diabetes,and Alzheimer’s have been treated.M.royleanus（Wall.ex Lawson）and P.lanceolata are essential MPs known for their therapeutic potential.On the other hand,nanoparticles（NPs）synthesized from fauna/flora extracts and Ag,Au,Pt,and Cu elements also had great importance.Silver nanoparticles（Ag·NPs）of P.lanceolata synthesized under different environment-friendly approaches have shown a great range of biological activities.Also,the 2D transition metal carbides,e.g.,titanium carbides Ti₃C₂T_x（MXene）,and their nanohybrid materials with Ag·NPs demonstrated their unique architecture and technology.It has been widely known as a catalyst,anti-bacterial and antioxidant.A novel nanohybrid composite material（Ag NPs@MXene）from Ag·NPs and MXene has also been synthesized.In this dissertation,the research works related to the MPs,its isolated natural products,Ag’s nanoparticle synthesis,and Ag NPs@MXene nanohybrid.The dissertation aims to provide a new way for NP and NPs and the new cutting-edge concept of MXene entry into the field of medicine to help remedy various incurable diseases.The main research works performed are in the following three parts:（1）M.royleanus is an important medicinal plant known for its therapeutic potential.NP was isolated from the plant stem in methanol.This crude extract was then separated on polarity bases into n-Hexane（FZH）,dichloromethane（FZD）,ethyl acetate（FZA）,and aqueous fraction（FZM）by respective solvents.For their phytotoxic,anti-fungal,and anti-bacterial bioassay,all these fractions were used.The phytotoxicity of FZH,FZD,FZA,and FZM showed inhibition(FI₅₀)of 128.52,241.13,243.74,and 242.63,respectively,for Lamina minor.In the case of anti-fungal activity,Rhizophydium graminis showed inhibition of 5%for FZA.The Uncinocarpus reesii showed 20%inhibition for FZD and 15%for FZA.The Aspergillus niger gave 10%inhibition for FZH,35%for FZD,50%for FZA,and 25%for FZM.Aspergillus flavus showed only 50%inhibition for FZM.For anti-bacterial tests,Escherichia coli has 16%inhibition in FZA fraction only.The Proteus vulgaris have 40.92%,8%,and 5%with FZH,FZD,and FZA,respectively.Activity-based assessment of FZD stemmed from the segregation of two very important sesquiterpene having dihydro-β-agarofuran alkaloids,i.e.,Euonymine and Chuchuhuanine EI,for the first time in M.royleanus collected from district Buner,Khyber Pakhtunkhwa,Pakistan.Both the alkaloids are the best acetylcholinesterase and butyrylcholinesterase inhibitors by assessing against enzymes.Euonymine presented significant acetylcholinesterase(IC₅₀:47.07±54μM)and butyrylcholinesterase(IC₅₀:55.78±1.0μM)inhibitory activities.Chuchuhuanine EI posed restrained,acetylcholinesterase(IC₅₀:182.97±1.25μM)and substantial butyrylcholinesterase(IC₅₀:47.07±0.54μM)inhibitory activities.The rational feedback would facilitate the development of medicines to treat a variety of diseases in the early stages.（2）Ag·NPs have shown a great range of biological activity,synthesized under different environment-friendly approaches.Using aqueous crude extract（ACE）,isolated from P.lanceolata,Ag·NPs have been synthesized.The ACE and Ag·NPs were characterized and assessed for their biological and antioxidant activities.The existence of NPs was confirmed by color shift and UV-Vis’s spectroscopy.Fourier transform infrared spectroscopy（FT-IR）analysis indicated the association of biomolecules（phenolic acid and flavonoids）in the reduction of silver（Ag⁺）ions.The SEM study demonstrated a sphere-shaped and mean size in the range of 30±4 nm.The EDX spectrum revealed that the Ag·NPs were composed of54.87%Ag with a 20 nm size identified by SEM and TEM.Also,the DRS and BET support the Ag·NPs pore size.The TEM image showed aggregations of NPs and physical interaction.Ag·NPs showed efficient activity compared to ACE,and finally,the bacterial growth was impaired by biogenic NPs.The lethal dose(LD₅₀)of Ag·NPs against Agrobacterium tumefaciens,Proteus vulgaris,Staphylococcus aureus,and Escherichia coli were 45.66%,139.71%,332.87%,and 45.54%with IC₅₀（08.02±0.68）,（55.78±1.01）,（12.34±1.35）and（11.68±1.42）respectively,suppressing the growth as compared to ACE.The antioxidant capacity,i.e.,2,2-diphenyl-1-picrylhydrazyl（DPPH）of Ag·NPs was assayed.ACE and Ag·NPs achieved a peak of antioxidant capacity of 62.43±2.4 and 16.85±0.4 at 100(g m L^-1,respectively)compared to standard(69.60±1.1 at 100μg m L^-1)with IC₅₀（369.5±13.42and 159.5±10.52）respectively.Finally,Outstanding antioxidant and antibacterial activities have been shown by NPs and can be used in various biological techniques in future research.（3）2D MXene-based nanohybrid have attained tremendous attention due to their unique physiochemical properties and wide range of applications like catalytic,anti-bacterial,and antioxidant activities.Herein,the research demonstrated a novel bioactive and antioxidant composite material（Ag NPs/MXene nanohybrid）using Ag·NPs（of P.lanceolate stem aqueous crude extract（ACE））and MXene with improved results in their anti-bacterial effect on Escherichia coli and Staphylococcus aureus and its degradation 4-nitrophenol,2-nitrophenol,and Congo red dye.The XRD,SEM,TEM,and XPS analysis evinced the Ag NPs@MXene nanohybrid synthesized from MAX to MXene and combined with Ag·NPs in stepwise procedures.Ag NPs@MXene nanohybrid antimicrobial activities were substantiated by denaturation of the bacteria cell wall,Methicillin-Resistant Staphylococcus Aureus,Escherichia coli,and Candida Albican fungus.Ag NPs@MXene nanohybrid have depleted pollutants such as 4-nitrophenol,2-nitrophenol,and noxious pigments Congo red.All the result conclude that the resultant Ag NPs@MXene has excellent and expected to be immune to biological fouling,bactericidal,and capable of degrading performance for various contaminants,making it the strongest nanomaterial for water treatment and other health-related issues.The study demonstrates the effectiveness of nanohybrid material as a promising candidate for antioxidant activities and is set to pave the way to explore other hybrid systems to improve the efficacy of medical systems in the future.Providing an essential and authentic role in medicine and water treatment is the critical finding in the dissertation.To explore the resources of MPs,NPs,and hybrid nanocomposites of MXene to benefit human,animal,and plant health in this area and increase the overall level of technical capacity.