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ThesisItem Embargo Synthesis of paddy straw biopolymers based hydrogels and their use as media for plant growth(Punjab Agricultural University, 2022) Jaswinder Kaur; Mankoo, Ramandeep KaurPaddy straw consists of three important biopolymers i.e. cellulose, hemicellulose and lignin which can be used for the production of various highly demanded sustainable organic products. Microcrystalline cellulose (MCC) and lignin were extracted from paddy straw by using the dilute acid pre-treatment method followed by alkaline hydrolysis. Characterization of MCC was done by FT-IR, SEM images and lignin was characterized by FT-IR spectrum. Hydrogels were synthesized using MCC and lignin as the raw material, PVA as the matrix template, glutaraldehyde and Epichlorohydrin (ECH) as cross-linkers and characterized by FT-IR and SEM analysis. Hydrogels synthesized using glutaraldehyde crosslinker were observed to have less porosity and tight bonding network whereas ECH caused loose bonding between polymers and resulted in formation of large pores in hydrogels. Swelling ratio and reswelling capacity of hydrogels showed that lignin hydrogels performed best than all other hydrogels. Monocot (wheat) and dicot (moong bean) seeds were found to germinate on hydrogels which confirmed the tendency of hydrogels to modify the water retention properties of growing media. The physiological parameters i.e. total fresh and dry biomass, leaf area, seedling length of hydrogels on growth of germinated seedlings were observed under control and water stress conditions. All hydrogels performed well under stress conditions as compared to control. However, both lignin hydrogels performed best and gave highest growth under stress conditions. It was concluded that these biopolymer based hydrogels can be recommended for use as growth media ingredient in water deficient conditions.ThesisItem Embargo Synthesis of boron and phosphorous doped graphene fabricated with magnesium ferrite – bentonite nanocomposite for the remediation of pollutants(Punjab Agricultural University, 2022) Manpreet Kaur; Manpreet KaurGraphene oxide (GO) doped with heteroatoms are gaining interest in depollution of water because of their large surface area. The boron-doped GO (B-GO), phosphorous-doped GO (P-GO) and boron and phosphorous co-doped GO (BPGO) in different w:w ratios were synthesized and fully characterized using analytical techniques viz. FT-IR, XRD, SEM-EDS, TEM, BET, Mössbauer and XPS. In order to impart magnetic features to doped GO materials, magnesium ferrite-bentonite (MGF-B) was used to fabricate nanocomposite of MGF-B and BPGO having hierarchical nanoflowers like morphology (HNFs). TEM of co-doped GO showed more wrinkled surface than doped GO, whereas in case of HNFs, chiffon-like BPGO nanosheets were wrapped on the MGF-B surface, resulting in a porous flower-like morphology. The synthesized materials were explored as adsorbents for the removal of Pb(II) and As(III) ions and as photocatalysts for the degradation of martius yellow, p-nitrophenol and malathion from synthetic waste water. The trend for the percentage removal of heavy metals by adsorption and degradation of organic pollutants by photocatalysis in the descending order was found to be: HNFs > BPGO-1:1 > BPGO-1:5 > BPGO-1:0.2 > MGF-B > P-GO > B-GO > GO. The adsorptive and photocatalytic potential of HNFs was greater as compared to pristine, doped and codoped GO due to high surface area, remarkable charge transfer ability and layered structure of codoped GO sheets. The HNFs possessed appreciable saturation magnetization than doped and co-doped GO layers, which led to its easy separation and reusability. Box-Behnken design was utilized for exploring the simultaneous effects of the independent variables on removal of metal ions and degradation of organic pollutants (as dependent variable) using HNFs. The adsorption and photocatalytic mechanism was proposed on the basis of adsorption isotherm, thermodynamic, kinetic and quenching studies. Enhanced activity of HNFs with adsorption of heavy metal could be defined by the electronic structural properties of elements. The best adsorbent and photocatalyst were also tested for spiked solution containing different metal ions and real life industrial water matrices.ThesisItem Embargo Synthesis of xylan and lignin based hydrogels and their use as growth media for rice (Oryza sativa)(Punjab Agricultural University, 2023) Japanpreet Kaur; Ramandeep KaurLignocellulosic biomass is the most economical and highly renewable crop residue in the world. It is nonedible plant material composed of cellulose, hemicellulose, and lignin and is present in environment as agriculture wastes which includes crop residues like paddy straw, wheat straw, etc. Lignin and xylan were extracted from paddy straw by pre-acid treatment which was followed by alkaline hydrolysis. Structural characterization of lignin and xylan was done by FT-IR and 1H-NMR spectra respectively. Different hydrogels were synthesized using lignin and xylan as the raw material, PVA as the matrix template, citric acid, and succinic acid as crosslinkers and were structurally characterized by FT-IR and SEM analysis. Hydrogels that were synthesized using citric acid as crosslinker were observed to cause loose bonding between polymers and resulted in formation of large pores in hydrogels whereas, hydrogels synthesized using succinic acid as crosslinker were observed to have less porosity and tight bonding network. The swelling ratio and reswelling capacity of hydrogels revealed that lignin hydrogels outperformed all other hydrogels. All the synthesized hydrogels were tested for their role as soil culture media ingredient for the germination of rice seedlings. Germination percentage was calculated on seventh day after sowing of rice seeds and it came out to be maximum in case of xylan/lignin hybrid citric acid crosslinked (LXC) hydrogels in both normal and stress conditions. Seedling length, total fresh weight, total dry weight, and leaf area were calculated after 30 days. All the hydrogels performed well in stress conditions as compared to normal conditions. Xylan/lignin hydrogel and lignin hydrogel synthesized using citric acid performed best and showed highest growth under stress conditions. It was concluded that the synthesized hydrogels could be used effectively as an ingredient of soil culture media owing to their tendency to absorb and retain water properly.ThesisItem Open Access Nanocomposite of magnesium ferrite and manganese oxide as polyphenol oxidase mimic and photocatalyst(Punjab Agricultural University, Ludhiana, 2022) Harmilan Kaur; Manpreet KaurArtificial enzymes have received immense interest due to their exceptional properties such as high stability and low-cost. Polyphenol oxidase enzyme mimic is well known for its contribution in the field of food industry, biosensors, medicine and water remediation. In the present study, Mn3O4 and MgFe2O4 nanoparticles and nanocomposites were synthesized by sol-gel and ultra-sonication methods. Their polyphenol oxidase (PPO) mimic activity was comparatively analyzed. The synthesized nanoparticles and nanocomposites were characterized by FT- IR, XRD, SEM-EDS, BET, and VSM. The results revealed that MgFe2O4@Mn3O4 possess unique catalytical features. XRD analysis of synthesized materials depicted crystalline nature. The PPO-like activity of synthesized NPs and NCs were analyzed using catechol and resorcinol as substrates. MgFe2O4@Mn3O4(1:2) were observed to be the best PPO mimic. Kinetic analysis under optimized conditions indicated higher binding affinity of nanocomposite as compared to pristine manganese oxide. MgFe2O4@Mn3O4 (2:1) showed to be best photocatalytic potential for catechol and resorcinol degradation in aqueous solution. The efficiency of degradation was put to the test in relation to the variation of several experimental parameters including: pH; nanoparticles dose and contact time These aforementioned parameters were optimized and examined for the influence that they exerted on the efficiency of degradation which involved the usage of the Box-Behnken design methodology. According to the ANOVA results that yielded a confidence level of 95 %, a high regression along with fitting values were obtained between the results of the experimental degradation of catechol and resorcinol and the predicted quadratic model. Thus, the present study indicated that a catalyst of MgFe2O4@Mn3O4 nanocomposite in different ratios have promising performance as photocatalyst and PPO-mimic for degradation of polyphenols.ThesisItem Restricted Evaluation of doped strontium ferrite nanoparticles functionalized with silica, carbon quantum dots and Cl-doped graphene for the removal of contaminants(Punjab Agricultural University, 2022) Grewal, Jaspreet Kaur; Manpreet KaurDoped spinel ferrites and their functionalized nanocomposites with silica (SiO2), carbon quantum dots (CQDs) and chlorine doped graphene oxide (Cl-GO) have attracted immense interest as adsorbents and photocatalysts for water remediation. This work reports the facile strategy for the synthesis and evaluation of Sr1-xTixFe2O4+δ, SiO2, CQDs, Cl-GO and their functionalized nanocomposites for the removal of Cd(II), As(III), p-nitrophenol, pendimethalin and martius yellow from contaminated water. The structural, magnetic, adsorptive and photocatalytic properties were comprehensively studied using different analytical techniques viz. XRD, XPS, FTIR, BET, VSM, TEM, SEM-EDS and 57Mӧssbauer spectroscopy. TEM micrographs revealed the decreased extent of agglomeration in Sr0.4Ti0.6Fe2O4.6 and Sr0.7Ti0.3Fe2O4.3 due to the introduction of non-magnetic Ti4+ ions. TEM image of Sr0.4Ti0.6Fe2O4.6-Cl-GO NC displayed wrinkled nanosheets of Cl-GO containing ferrite NPs with particle size of 25-30 nm distributed over their surface. The fabrication of core-shell nanostructures with SiO2 was clearly visible from their TEM micrographs. The trend for the percentage removal of heavy metals by adsorption and degradation of organic contaminants by photocatalysis in the descending order was found to be: Sr0.4Ti0.6Fe2O4.6-Cl-GO > Sr0.4Ti0.6Fe2O4.6-CQDs > Sr0.4Ti0.6Fe2O4.6@SiO2 > SiO2@Sr0.4Ti0.6Fe2O4.6 > Sr0.4Ti0.6Fe2O4.6. The increased adsorption potential of functionalized nanocomposites as compared to pristine NPs was attributed to the increased surface area, functional moieties, and decreased particle size. The higher photocatalytic efficiency of Sr0.4Ti0.6Fe2O4.6-Cl-GO nanocomposite could be ascribed to the fast charge transfer, stabilization and hindered recombination of electron-hole pairs at the interface of Cl-GO and Sr0.4Ti0.6Fe2O4.6 NPs. Box-Behnken Design (BBD) of response surface methodology was utilized for exploring the simultaneous effects of independent variables on the removal of heavy metal ions and organic pollutants using Sr0.4Ti0.6Fe2O4.6-Cl-GO nanocomposite. The best adsorbent and photocatalyst were also tested for spiked solution containing different metal ions and real life water matrices.ThesisItem Embargo Synthesis of pyrimidinone derivatives and their antimicrobial activity(Punjab Agricultural University, 2023) Baljinder Kaur; Utreja, DivyaAn efficient protocol has been used for the synthesis of pyrimidinone derivatives via a onepot three-component condensation reaction of aryl aldehydes, malononitrile and barbituric acid in aqueous conditions using tetrabutylammonium hydrogen sulfate. A simple procedure, short reaction time, high yields (78–93 %), broader substrate scope, easy handling of the catalyst and simple work-up, i.e., non-column chromatographic separation of the desired products were attractive features of this process. The structures of synthesized derivatives (4aj) were confirmed by spectral analysis. The in vitro antimicrobial activity of the compounds was determined by the agar well diffusion method against Dickeya sp. (Gram-negative bacteria) and Streptomyces scabiei (Gram-positive bacteria). The synthesized compounds exhibited zone of inhibition at 10.67 ± 0.33, 9.50 ± 0.29 and 10.75 ± 0.14 mm in diameter for (4f), (4g) and (4j) respectively against Dickeya sp., compared to Gentamicin as standard (zone of inhibition at 19.17 ± 0.22 mm). The compounds were found to be potent towards the antioxidant activity. Using H2O2 scavenging assay, the derivatives (4g), (4j), (4i) and (4f) emerged to display promising antioxidant activities with inhibition percentages at 82.01 ± 0.28, 81.57 ± 0.34, 80.97 ± 0.19 and 76.97 ± 0.29 respectively, similar to the ascorbic acid and gallic acid (percent inhibition of 80.46 ± 0.32 and 79.51 ± 0.10, respectively) used as reference standards.ThesisItem Embargo Synthesis of thymol functionalized chemosensor and evaluation of its cytotoxicity to plant growth promoting rhizobacteria(Punjab Agricultural University, 2023) Ramneet Kaur; Gaba, JyotiA chemosensor (TPC) based on thymol was afforded by reaction of thymol and piperidine in methanol. The structure elucidation of TPC was done by UV-Vis, H-NMR, "C-NMR and FT-IR analysis. The absorption spectrum of TPC showed a band at 277 nm. The presence of Cu and Pb ions induced increase in the absorption intensity at 277 nm by 2-fold and 1.5- fold, respectively. Although, no alteration was observed in the UV-Visible spectra with the addition of other metal ions. The binding constant for both TPC-Cu and TPC-Pb was calculated as 1.55 >x 10° M and 1.47 x 10° M, respectively. The deduced limit of detection (LOD) and limit of quantification (LOQ) for Cu was 623.64 and 1889.85 uM, respectively. For Pb ions, LOD and LOQ was calculated as 676.70 and 2050.60 M, respectively. The binding stoichiometry was estimated as 1:1 by Job's plot method of continuous variation for both TPC-Cu and TPC-Pb* complex. TPC was also checked for reusability with EDTA, which was found effective for upto two cycles. The synthesized probe was further used for determination of concentration of Cu and Pb ions in spiked tap water samples and percent recovery were observed in range of 80.l to 81.0 % and 80.1 to 81.9 % for Cu and Pb ions, respectively. The cytotoxic study was also conducted which inferred that the compound TPC was non-cytotoxic against tested plant growth promoting rhizobacteria (PGPR) i.e. Rhizobium sp., Pseudomonas sp., and Azospirillum sp. at all the tested concentrations.ThesisItem Embargo Synthesis and evaluation of various of metal salicylates nano formulations against pathogenic fungi of rice(Punjab Agricultural University, 2022) Gandhi, Garima; UrvashiFive 2-oxobenzoatometal complexes viz. tetraaquo(2-oxobenzoato)zinc(II) dihydrate (1), sodium diaquobis(2-oxobenzoato)zincate(II) (2), sodium tris(2-oxobenzoato)zincate(II) (3), diaquo(2-oxobenzoato)copper(II) dihydrate (4) and sodium bis(2-oxobenzoato)cuprate(II) (5) were synthesized using a standard methodology having different molar ratios of metal and 2oxobenzoato ligand (salicylate ligand). They were further nanoformulated via. sonication and laser disintegration technique (blue laser). The in vitro antifungal evaluation revealed more profound results of laser disintegrated samples for inhibiting the fungal menace of two seed borne fungal pathogens of rice viz. F. fujikuroi and F. verticillioides. Sodium bis(2oxobenzoato)cuprate(II) (l-CuSA2) was the most effective in inhibiting the mycelium growth of both the test fungi i.e. F. fujikuroi and F. verticillioides, with ED90 values of 2347.17 + 0.28 μg/ml and 2373.41 + 0.47 μg/ml, respectively. Nanopriming of most infested rice seeds (PUSA 1509) with l-CuSA2 at 2500 μg/ml showed the best seed health and quality parameters and is accounted as the best nanoformulated complex which have opened the doors for further elaborative study for its utilization as seed nanopriming agent in agrosystems to replace Carbendazim (banned fungicide) for seed treatment.ThesisItem Restricted Chemistry and antioxidant potential of Tinospora cordifolia extracts and its bioactive compound(s)(Punjab Agricultural University, 2022) Poonamdeep Kaur; UrvashiThe present investigation deals with chemistry and antioxidant potential of Tinospora cordifolia extracts and its bioactive compound(s). The mineral analysis of the stem powdered showed the presence of potassium in the highest concentration whereas cadmium in the lowest concentration. The methanol extract of stem was prepared using Soxhlet apparatus and partitioned into polar and non-polar fractions using dichloromethane, chloroform and hexane as solvent. Qualitative analysis of phytochemicals affirmed the presence of phenols, flavonoids, saponins, alkaloids, tannins, terpenoids, steroids and cardiac glycosides in methanol extract. The total phenolic, flavonoid and alkaloid content of methanol extract was found to be 2.90±0.36mg GAE g-1, 3.79±0.48mg QE g-1 and 0.09379±0.45 mg B g-1, respectively. The major compound berberine was isolated from the chloroform fraction of T. cordifolia using column chromatography and the structure of compound was elucidated on the basis of spectroscopy analysis. Antioxidant potential was carried out using five different in vitro models involving 2, 2-diphenyl-1-picrylhydrazyl (DPPH) , hydroxyl (OH), nitric oxide (NO), superoxide (O2) radicals scavenging methods and ferric reducing antioxidant power assay (FRAP) at various concentrations (0.02-0.1 mg ml-1). The antioxidant activity increased with increase in concentration. Methanol extract was found to be most active as compared to other fractions. The antioxidant activity of methanol extract was comparable of berberine. Hence, methanol extract and berberine showed good potential as a source of natural antioxidants.
