Analysis of Compound 109 using 13C NMR Spectra

Analysis of fuse 109 using 13C NMR SpectraThe 13C NMR spectrum of raise 109-114 is represented in plate 40-45. Structural elucidation of 109 by 13C NMR spectrum has been described and it was confirmed from the devil dimensional NMR reports of 109. Assignments for the former(a) compounds 109-114 made by compa make noise with compound 109. Table 33 lists the chemical shift values of 109. A array of forecasts resonated in the aliphatic region at 20.85, 26.60 and 27.98 ppm of the three manoeuvres in the aliphatic region, signals at 20.85, 26.60 and 27.98 ppm are delegate to C-7, C-6 and C-8, respectively. The C-5 signal is merged with solvent signal. In addition to this, the benzylic carbon signals C-2 and C-4 were resonated at 64.53 and 62.52 ppm respectively, whereas the footing carbon C-1 was appeared at 45.69 ppm. Moreover, a collection of signals appeared in the region 102.69-131.40 ppm, which are unambiguously assigned to aryl carbon. A part from the assigned signals, two si gnals resonated in the down correction at 142.56 and 142.72 ppm is assigned to ipso carbons. Another four unassigned signals resonated in the down field region at 159.55 to 166.27 ppm and these signals belong to C=0, C=N, C-OH carbons respectively.1H-13C COSY spectra ordered series 46 and 47 represents the 1H-13C COSY spectrum of 105 and the correlations showed in Table 34. HMBC (Plate 40) and HSQC (Plate 41) correlations shit been used to assign the benzylic carbons, ipso carbons of aryl group, and methyl groupene carbons (C-6, C-7, and C-8). The benzylic protons observed at 4.30 (H-2a) and 4.25 ppm (H-4a) showed cross peak with 64.33 (C-2) and 62.52 ppm (C-4), which whitethorn be due to the C-2 and C-4 carbons of the piperidone heterocyclic of the ABN trunk. The bridgehead methine proton signals at 2.50 (H-1e) and 2.98 (H-5e) ppm was correlated with the carbon signals at 45.69 ppm (C-1) and 39.57 ppm (C-5). This indicates that the signals appeared at 45.69 and 39.57 ppm is unam bigously assigned to C-1 and C-5 carbons. thwartwise peak with the protons resonated at 2.77 (H-7a) and 1.27 (H-7e) ppm was correlated with the carbon signal at 20.85 ppm and this confirms the signal at 20.85 ppm was solely specific to C-7 carbon.H-6a and H-6e protons appeared at 1.45 and 1.60 ppm showed cross peak with 26.60 ppm (C-6 carbon), which confirms that the signal at 26.60 ppm was due to C-6 carbon and the carbon signal at 20.85 ppm was attributed to the correspondent C-7 carbon. Similarly, the H-8e (1.63 ppm) and H-8a (1.55 pm) protons was correlated with the carbon signal at 27.98 ppm (C-8), which suppors that the signal at 27.98 ppm was ascribed to the cyclohexane noise carbon C-8.Analysis of spectra of 109-1141H and 13C NMR spectral analysis of other compounds much(prenominal) as N-(2,4-bis(4-chlorophenyl)-3-azabicyclo3.3.1nonan-9-ylidene)-2,4-dihydro-xybenzohydrazide101, N-(2,4-bis(4-fluorophenyl)-3-azabi-cyclo-3.3.1nonan-9-ylidene)-2,4-dihydroxybenzohydrazide 102 , N-(2,4-bi-s(4-bromophenyl)-3-azabicyclo3.3.1nonan-9-ylidene)-2,4-dihydroxy-benzohydrazide 103, N-(2,4-dip-tolyl-3-azabicyclo3.3.1 nonan-9-ylidene)-2,4-dihydroxybenzohydrazide 104, N-(2,4-bis(2-chloro-phenyl)-3-azabicyclo3.3.1nonan-9-ylidene)-2,4-dihydroxy-benzohy-drazide 105 was analyzed in a similar counselling of 109. The chemical shift and splitting patterns observed using 1H and 13C NMR assignments for other compounds is presented in Tables 35 and 36 and their corresponding spectra are given in Plates 33-37 41-45, respectively. Tables 37-42 show the brief description of analytical and spectral data of compounds 109-114. taken together, all the above observations substantiate the proposed coordinate and twin-chair (CC) conformation of 2r,4c-diaryl-3-azabicyclo 3.3.1 nonan-9-one-4-methyl-1,2,3-thiadazole-5- carbonyl hydrazones 102-108.Biological subscribe toFree basal scavenging performanceIntensity of the warrant substructure scavenging electromotive force strongly de pends upon its chemical structure. Several studies have demonstrated that the let go of prow scavenging effectuate is noticeably influenced by the number and position of hydroxyl groups on the D telephone and by the extent of conjugation between the D sidestep amide carbonyl group 1-4. The dihydroxy structure in the D ring confers high stability to the hydrazones phenoxyl al-Qaeda via hydrogen bonding or by electron delocalization. The amide carbonyl group double bond (Conjugation with the amide oxo group) determines the coplanarity of the phenyl ring and participates in radical stabilization via electron delocalization over all ring system 4. Initial studies on analysis of free radical scavenging potential of diaryl 3-azabicyclononanones revealed a concentration dependent weak anti-radical activity resulting from reduction of DPPH, ABTS+, O, OH, and azotic oxide radicals to their non-radical forms. In order to bring the dihydroxy structure in the D ring and the amide carbon yl group double bond (Conjugation with the amide oxo group) into diaryl 3-azabicyclononanones to enhance the free radical potential (figure 14), We therefore synthesized N-(2,4-diaryl-3-azabicyclo3.3.1nonan-9-ylidene)-2,4-dihydroxybenzohydrazide (109-114) by the reaction of 95,96,98-101 with 2,4-dihydroxybenzoic hot hydrazide (94) in the charge of acetic caustic.All the tried and true compounds showed a concentration dependent anti-radical activity against variant free radicals. IC50 values for the free radical scavenging effects of ascorbic acid and various synthetic compounds (109-114) are shown in Table 43.This whitethorn be due to the hydrogen fraction bequest mechanism and the electron donation mechanism. In the hydrogen atom transfer mechanism, hydroxyl groups donate hydrogen to a radical stabilizing it and giving rise to a relatively stable hydrazones phenoxyl radical. Figure 15 illustrates the probable mechanism of hydrogen atom donating ability of compounds 109-114. The electron donation mechanism involves through the strong hydrogen bond of -OH mediety with the oxygen atom of amide carbonyl group that may prevent efficient deprotonation and enhance their radical scavenging action by doer of hydrogen atom donation. Figure 16 illustrates the probable mechanism of free radical scavenging effects of compounds 109-114 through electron donating mechanism. Structure A is the conjure neutral molecule of compounds 109-114. Structure B is the sign radical ions and structure C is its more stable tautomeric form. The tautomeric form C of the radical ions results from the initial radical ions B and proton transfer from C-2 -OH to carbonyl groups.We found required morphologic features to scavenge free radical in our tested compounds (109-144). However, we have spy a diverse range of effects against various free radicals. This may be due the different substitution at the C-2 and C-6 positions of the azabicyclononan-9-one mediety. Compound 8 devoid of any substituents at the space-reflection symmetrytrooper position of the phenyl groups at the C-2 and C-6 positions of the azabicyclononan-9-one moiety and phenyl rings with electron-donor methyl groups at the para position of compounds 113 showed excellent free radical scavenging effects compared to measure antioxidant ascorbic acid, a known antioxidant used as a positive control. This may be due to incorporation of methyl groups at para position phenyl ring. Several studies have demonstrated that organic fertiliser molecules incorporating a methyl groups can act as free radical trapping agents and are capable of opposing oxidative challenges 5,6. Compounds possessing electron-withdrawing chloro (110/114), bromo (111), and fluoro (112), substitutions at the para position of the piperidine moiety showed admirable in vitro free radical scavenging effects against various free radicals. This admirable or less free radical scavenging effects of compounds with bromo, choloro and fluor o substitutions may be due to the electron-withdrawing inductive effect of halogens. The results obtained in the present study are in line with other findings 7,8. interpreted together, the current research suggests that azabicyclononane ring ensuring hydroxyl groups on the D ring and by the extent of conjugation between the D ring amide carbonyl group with strong free scavenging effects (111) may conceivably head to its protective effects against free radical-induced oxidative stress and carcinogenesis.Antibacterial and antimycotic agent activitySynthesized compounds 109-114 were examined for their bactericide and antifungal potencies. In vitro studies by twofold ordered dilution method was adopted. Streptomycin/ streptomycin/ fluconazole were used as a positive control. Table 44 shows the MICs of test compounds 109-114. Analysis of in vitro antimicrobial effects of all the N-(2r,4c-diaryl-3-azabicyclo3.3.1nonan-9-ylidene)-2,4-dihydroxybenzohydrazide 109-114 revealed a diverse range of (1.56-200 g/mL) against the various bacterias and fungus. The compounds deprived of any substituents at the aryl rings in 109 hinder the growth of all bacteria and fungus at a MIC value of 100-200 g/mL. However, compounds 110, 111 and 112 possessing para halo (electron withdrawing substitutents chloro, fluoro and bromo) substituted aryl groups in azabicyclononane moiety accounts for the enhanced inhibitory effects against B. subtilis, K. pneumonia, P. aeruginosa, S. aureus, A. flavus, A. Niger, C. albicans, and Candida6 at MIC values of 1.56-25 g/mL when compared to the standard antibiotic streptomycin/ fluconazole.Several studies have also documented that electron-withdrawing groups (fluoro, bromo and chloro) substituted azabicyclononan-9-one derivatives exhibited dandy antibacterial and antifungal activities 9,10. Compound 114 with ortho chloro substituent in the phenyl moiety displays proficient antibacterial activity against all pathogens. Other compounds displayed re duced inhibitory effects against various bacterial strains compared to the standard streptomycin/ fluconazole. The results of the present study demonstrates that electron withdrawing groups at the para position of the aromatic ring in azabicyclononan-9-one moiety exert first-rate inhibitory effect against various tested microbes compared to the other test compounds and standard drug. The SARs based on IC50 values (table 44) showed that variations in substitution of the aryl groups at C-2 and C-4 position of the azabicyclononane ring may have significant impact on the anti-microbial activity against various microbes.ConclusionThe chemical condensation of diversely substituted diaryl 3-azabicyclononan-9-ones with 2,4-dihydroxybenzoic acid hydrazide in the presence of acetic acid provide corresponding hydrazones 109-114 with change magnitude antioxidant potential and anti-microbial effects. Although various hydrazones exerted the free radical scavenging effets in a good dose-dependen t manner, compound 109 and 113 were more active in scavenging free radicals than their parent hydrazones and ascorbic acid. In addition, the results of the antimicrobial activities of hydrazones revealed that compounds 110, 111 and 112 possessing para halo (electron withdrawing substitutents chloro, fluoro and bromo) display promising activities against all tested microorganisms. The results of the present study provide a further insight into the morphologic requirements to develop potential new antioxidants and anti-microbial agents.