Biologically potent compounds are one of the most important classes of materials for the upcoming generations.
Increasing number of microbial infectious diseases and resistant pathogens create a demand and urgency to develop novel, potent, safe and improved variety of antimicrobial agents.
The copper surfactants substituted 2-amino-6-methyl benzothiazole were synthesized. The synthesized complexes have been characterized by IR, NMR, ESR spectroscopic methods. The antifungal activities have been evaluated by testing against Alternaria alternate fungi. All complexes showed good antifungal activity because chelation increases the anti-microbial potency.
The studies suggest that the copper (II) ions in soaps may be responsible for the enhancement of the activity against fungi. The evaluation of anti -fungal studies further revealed that fungitoxicity of the complexes also depends on the nature of metal ions. The chelation reduces the polarity of central metal ion mainly because of partial attaining of its positive charge with the donor groups and possible π- electron delocalization over the whole chelate ring. Such chelation increases the lipophilic character of the central atom, which subsequently favors its permeation through the lipoid layer of the cell membrane. Their efficiency increases with their concentration.
Open Peer Review Details | |||
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Manuscript submitted on 22-03-2018 |
Original Manuscript | Antifungal Activities and Characterization of Some New Environmentally Safe Cu (II) Surfactants Substituted 2-Amino-6-Methyl Benzothiazole |
Colloidal surfactants have become one of the most important requirements in day to day life, and have great importance in modern engineering and pharmacological fields. Many copper thiosemicarbazone complexes have been found to have significant anti-tubercular, fungicidal and antitumor activities [1Sharma A K, Saxena M, Sharma R. Synthesis, spectroscopic and fungicidal studies of Cu (II) soaps derived from groundnut and sesame oils and their urea complexes Bulle Pure Appl Sci (2017) 36(2) 26-37, 2Bhati SK, Kumar A. Synthesis of new substituted azetidinoyl and thiazolidinoyl-1,3,4-thiadiazino (6,5-b) indoles as promising anti-inflammatory agents. Eur J Med Chem 2008; 43(11): 2323-30.
[http://dx.doi.org/10.1016/j.ejmech.2007.10.012] [PMID: 18063224] ]. The use of copper linoleate as heavy duty wood preservative and many other biological activities of copper metal-containing surfactants have also been studied [3Rashmi S, Arun K S. Natural Edible Oils: Comparative Health Aspects Of Sesame, Coconut, Mustard (Rape Seed) and Groundnut (Peanut) A Biomedical Approach. Biomed J Sci & Tech Res; 2017: 1(5)
[http://dx.doi.org/10.26717/BJSTR.2017.01.000441] , 4Tank P, Sharma AK, Sharma R. Thermal behaviour and kinetics of copper (II) soaps and complexes derived from mustard and soyabean oil. J Anal Pharm Res 2017; 4(2): 1-5.
[http://dx.doi.org/10.15406/japlr.2017.04.00102] ]. Recently, the deeper understanding of the role of metal ion in bio-system has led to the awareness that metal complexing is useful in the treatment of bacterial, fungicidal and viral diseases [5Sharma AK, Saxena M, Sharma R. Ultrasonic studies of Cu (II) soaps derived from mustard and soybean oils. J Pure Appl Ultrason 2017; 39(3): 92-9., 6Tank P, Sharma R, Sharma AK. Studies of Ultrasonic and acoustic parameters of complexes derived from Copper (II) surfactant of mustard oil with N and S atoms containing ligands in non- aqueous media (benzene) at 303.15 K. J. Acous Soc Ind 2017; 44(2): 87-99.].Many copper compounds are employed as pesticides either alone (as Cu (I) oxide and Cu (II) sulfate) or in mixtures [7Bhutra R, Sharma R, Sharma AK. Viscometric and CMC studies of Cu(II) surfactants derived from untreated and treated groundnut and mustard oils in non-aqueous solvent at 298.15 K J. Inst Chemists (India) 2017; 90: 29-47.]. Formulated proprietary brands of cuprous oxide are extensively employed as fungicides and seed dressings. Copper oxychloride has a number of applications, by far the most important being as an agricultural fungicide for which purpose it is extensively employed in formulated form as dust, wettable powders and pastes [8Tank P, Sharma R, Sharma AK. A pharmaceutical approach & Antifungal activities of copper soaps with their N & S donor complexes derived from mustard and soyabean oils. Glob. J Pharmaceu. Sci 2017; 3(4): 1-6.
[http://dx.doi.org/10.19080/GJPPS.2017.03.555619] -10Sharma A, K, Saxena M, Sharma R. (2018) Synthesis, Spectroscopic and biocidal activities of environmentally safe agrochemicals. J Biochem. tech. 7(3) 1139-47]. The effect of silver nanoparticles on various fungi has been reported recently [11Alananbeh K, Al-Qodah Z, Amira El-Adly A, Al Refaee W. Impact of Silver Nanoparticles on Bacteria Isolated from Raw and Treated Wastewater in Madinah, KSA. Arab J Sci Eng 2016; 1-9., 12Alananbeh K, Al-Qodah Z, El-Adly Amira, Al Refaee A. W., Antifungal effect of silver nanoparticles on selected fungi isolated from raw and waste water. Indian J Pharm Sci 2017; 79(4): 559.]. Therefore, a substantial research is needed for their discovery and improvement. Chemistry of present era aims to build a pollution free environment. For the same, it targets to create some alternatives which are eco-friendly and nature loving. The present research work is a step towards achieving such alternatives. For this, the copper surfactants substituted 2-amino-6-chloro benzothiazole were synthesized. The antifungal activities of these have been evaluated by testing against Alternaria alternate. The fungitoxicity results indicate that the strain of fungal species are susceptible towards these and suggests that with the increase in the concentration of copper surfactant and its complexes, it may increase further.
The acids (n–caprylic acid, n–capric acid and n–lauric acid) have been purified by keeping over anhydrous sodium sulphate for a week and then distilled under reduced pressure. The purity of acids was checked by the determination of their melting points. n - Caprylic acid (16.3 oC) n - Capric acid (31.2 oC), n - Lauric acid (44.0 oC). Copper soaps were prepared by direct metathesis of the corresponding sodium soap with a slight excess of the required amount of copper sulphate solution at 50-55oC. After washing with hot water and alcohol, the samples were dried at 100-105oC. Finally, under reduced pressure, they were recrystallized twice from hot benzene. Ligands were synthesized using thiocyanation method [13Khan S, Sharma R, Sharma AK. Antifungal activities of copper surfactants derived from neem (AzadirectaIndica) and Karanj (Pongamiapinnata) oils: A pharmaceutical application. Glob J Pharmaceu Sci 2017; 3(4): 1-6.]. The purity of the benzothiazoles has been checked by thin layer chromatography in various non-aqueous solvent systems. The metal was analysed by standard procedure. C, H, N, Cl and S analyses were performed at RSIC, CDRI Lucknow. In general, all the solid complexes (about 90% yield) with bluish green periphery were obtained (Table 1). These are soluble in ethanol, methanol, benzene and other organic solvents and insoluble in water. All the complexes are quite stable at room temperature up to 170oC. On the basis of elemental analysis, the complexes have been assigned the composition Cu2(CnH2n+1COO-)4L2, n=7,9,11 and suggested 1:1 type stoichiometry (Figs. (1-3
) [14Mahajan K, Swami M, Singh RV. Microwave synthesis, spectral studies, antimicrobial approach, and coordination behavior of antimony(III) and bismuth(III) compounds with benzothiazoline,2009; 35: 179-80. Russ. J. Coord. Chem. 35(2009)179-180;https://DOI: 10.1134/S1070328409030038].
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Fig. (1) Synthesis of ligand by thiocyanation method. |
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Fig. (2) Proposed structure of copper soap. |
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Fig. (3) Proposed structure of copper soap complex. |
1 ml of the soap solution was aseptically transferred into sterile petri plates. Into these plates, 20 ml of P.D.A. was poured and was mixed with soap solution by rotating the petri plates in clockwise and anticlockwise direction 3-4 times and was allowed to solidify. After the solidification of the above medium, single hypha / spore of test organism was aseptically transferred in the centre of the petri plates. The plates were incubated at 30 oC for 3 days. After the period of incubation, the plates were observed for the growth of fungus in different concentration of the soap solution used in the present study. The data were statistically analyzed according to the following formula [15Garg BS, Kumar DN. Spectral studies of complexes of nickel (II) with tetradentate schiff bases having N2O2 donor groups, Spectrochim. Acta 59A (2003): 229-234; https://DOI:10.1016/S1386-1425(02)00142-7].
% Inhibition = (C-T)*100/C
Where C = diameter of fungal colony in control plates after 3 days
T = diameter of fungal colony in test plate after 3 days
In order to study the structure of complexes, the infrared absorption spectra of compounds were obtained on a Perkin–Elmer 5100.4367 Spectrophotometer [4000-200 cm-1] and ESR analysis was made on Marker-TCNE analyser at RSIC, IIT Powai, Mumbai. 1H NMR spectra (C6D6) was recorded on an NMR spectrometer at RSIC, IIT Powai, Mumbai. The ESR spectra of the complex recorded on X-band at frequency 9.07 GHz under the magnetic field strength of 2000 ± 4000 and 3000 ± 2000 gauss at room temperature. ESR Spectrum is characterized by the position intensity and shape as to component lines. The position of ESR is referred as g values and is directly determined by the energy levels. The variation in g value is interpreted in terms of the first and second order spin-orbit interaction. The g values for ESR signal was calculated by the formulae [16Sharma S, Sharma R, Sharma AK. Synthesis, Characterization, and thermal degradation of Cu (II) Surfactants for sustainable green chem. Asian J Green Chem 2017; 2(2): 129-40.
[http://dx.doi.org/10.22631/ajgc.2017.95559.1015] ].
g = hν/βH
Where,
ν = Freq. of band in kHz. β= Bohr magneton
H = magnetic field
h = Planck’s constant
The detailed infrared spectral investigation reveals that there are marked differences between the spectra of pure copper soaps and pure ligand than those of the corresponding complexes (Table 2) The absorption bands observed in the region 2960-2950 cm-1 and 2900-2950 cm-1 respectively were assigned to the antisymmetric stretching for methyl group of the soap segment present in the complex. Symmetric stretching bands for methyl group has been assigned in the region 2820-2850 cm-1. It has been observed that the absorption peaks, which are characteristics of the aliphatic portion of the soap molecules, remain unchanged on going while being transferred from soaps to the complexes. The absorption spectra in the region 710-725 cm-1 may probably be due to the rocking vibration of a chain of methylene group –(CH2)n. The peaks in the region 1575-1590 cm-1 and 1400-1410 cm-1 are due to COO-, C-O anti-symmetric and symmetric stretching, respectively [17Sharma AK, Sharma S, Sharma R. Thermal degradation of Cu (II) metallic soaps and their characterizations. A pharmaceutical application chronicles of pharmaceutical science 2017; 1(5): 312-19.].
The presence of bands in the region 810±20 cm-1 was due to C-H deformation (in plane) present in the tri-substituted benzene ring of benzothiazole segment, where two hydrogens are adjacent [1,2,and 4 position]. In 2-amino-6-methyl benzothiazole, the C-H deformation vibration of –CH3 group has been observed at 1477 cm-1. C-N stretching (aryl tertiary) peaks was observed in the region 1360-1310 cm-1. C=N stretching peaks in the region 1460-1430 cm-1 was also observed. The C-S stretching bands present in the region of 700-600 cm-1 also confirm the structure of the molecule. IR spectrum of the pure ligand 2-amino-6-R benzothiazole [R= -CH3] contained peaks in the region 3450±15 cm-1 due to symmetric N-H stretching, which shifted to 3400±20 cm-1 on complexation, indicating the participation of the primary amino group in the chelation (Table 3) [18Sharma S, Sharma R, Heda LC, Sharma AK. Kinetic parameters and Photo Degradation studies of copper soap derived from soybean oil using ZnO as a photo catalyst in solid and solution phase. J Inst Chemists (India) 2017; 89(4): 119-36.].
The 1H NMR spectra of the complexes were collected in C6D6 and examined to determine bonding and tautomerism present in the structure. A perusal of the spectra of the complexes shows aliphatic –CH3 proton signal at δ - 0.9 and -CH2 proton signal at δ - 1.2 of soap segment, indicating the presence of soap segment in the complex molecule.
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Fig. (4) NMR spectra of ligand (2-amino-6-methyl benzothiazole). |
A broadened peak has been observed in all the spectra of the complexes at δ 3.2 – 4.2 due to the presence of aromatic –NH2 protons. In the given spectra of CCprAMB (Fig. 4), the above peak was clear which indicates the coordination through the –NH2 group of the benzothiazole segment to the metal atom of soap segment. The proton present in the nitrogen atom may undergo rapid, intermediate or slow exchange. The broadening of the observed peak is suggestive of a slow exchange because the electrical quadripole moment of the nitrogen nucleus induces a moderately efficient spin relaxation. A very weak signal was observed at δ - 8.5 in the spectra, which may be due to tautomerism present in the molecule of the complex similar to the pyrrole and indole. The triplets at δ 6.9 – 7.2 are may be due to tri-substituted aromatic protons of benzothiazole segment indicating that the environment of all the three protons is different. Another peak present at δ - 2.8 in the methyl substituted complex confirmed the presence of aromatic methyl group in the benzothiazole segment of the molecule suggesting a downfield shift [19Khan S, Sharma R, Sharma AK. Ultrasonic studies of Cu (II) Soap derived from seed oil of Pongamiapinnata(Karanj), in non-aqueous binary and ternary systems at 298.15K. Malasian J Chem 2017; 19(2): 99-110.].
Literature reveals that magnetic conductivity and spectral studies of complexes of some first-row transition elements with pyrazine carboxylic acid have been conducted , where it acts as a bidentate ligand through O and N donor atoms [20Bhutra R, Sharma R, Sharma AK. Comparative studies of treated & untreated oils as Cu (II) surfactants“ISBN978-3-659-83122-5 2017.].
The ESR spectra of the complexes synthesized by us were recorded on X-band at frequency 9.07 GHz under the magnetic field strength of 2000±4000 and 3000±2000 gauss at room temperature. The value of ESR parameters for all the complexes is given in Table 4. A perusal of Table 4 shows that the values of g, gII, are greater than the value of g0 ii.e. 2.0027. This indicates that the distortion from the regular octahedron has taken place in the shape of the complex. Also the trend gII>
for all the complexes indicates that the unpaired electron is most likely in dx2-y2 orbital of Cu (II) giving 2B1g as the ground state. This fact supports that complexes possess elongated octahedral geometry. It is well known that gII is a moderately sensitive function for indicating covalency. Thus, the values of gII are suggestive of the covalent character of metal-ligand bond [21Saxena M, Sharma R, Sharma AK. Micellar Features of Cu (II) surfactants derived from edible oils 2017., 22Mishra AP, Mishra RK, Shrivastava SP. Structural and antimicrobial studies of coordination compounds of VO(II), Co(II), Ni(II) and Cu(II) with some Schiff bases involving 2-amino-4-chlorophenol, J Serb Chem Soc 2009; 79: 523-35]. Earlier magnetic studies, about copper (II) soaps confirm the binuclear configuration in the solid state. However, the low values of the magnetic moments for copper ion present in copper (II) soaps in non-aqueous solvent like alcohol and hydrocarbon confirm that the binuclear configuration exists in the soap solutions and the dispersion unit is a binuclear molecule having the structure proposed in Figs. (5
-7
) [23Raval JP, Desai KG, Desai KR. Microwave synthesis, characterization and antimicrobial study of new pyrazolyl-oxopropyl-quinazolin-4(3H)-one derivatives. J Saudi Chem Soc 2011; 16(4): 387-93.
[http://dx.doi.org/10.1016/j.jscs.2011.02.003] , 24Chandra S, Jain D, Sharma AK, Sharma P. Coordination modes of a schiff base pentadentate derivative of 4-aminoantipyrine with cobalt(II), nickel(II) and copper(II) metal ions: synthesis, spectroscopic and antimicrobial studies. Molecules 2009; 14(1): 174-90.
[http://dx.doi.org/10.3390/molecules14010174] [PMID: 19127246] ].
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Fig. (5) ESR spectra of complex CCplAMB. |
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Fig. (6) ESR spectra of complex CCprAMB. |
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Fig. (7) ESR spectra of complex CLrtlAMB. |
The antifungal activities of the pure ligands, pure soaps and their corresponding complexes have been evaluated by testing against Alternaria-alternata [25Sharma AK, Saxena M, Sharma R. Acoustic studies of copper soap- urea complexes derived from groundnut and seasam oils. J Phy Studies 2017; 21(4): 4601-6.-26Sharma AK, Saxena M, Sharma R. Ultrasonic studies of Cu (II) Soaps derived from Groundnut and Sesame oils. Tenside Surf Det 2017; 55(2): 127-34.
[http://dx.doi.org/10.3139/113.110544] ] at a different concentration by Agar plate technique. A perusal of Fig. (8) reveals that all complexes show higher activity than pure soaps and ligands suggesting that complexes are more powerful antifungal agents and benzothiazole and other N, S, O etc [27Khan S, Sharma R, Sharma AK. (2018) Acoustic studies and other acoustic parameters of Cu(II) Soap derived from non- edible Neem oil (Azadirectaindica), in Non-aqueous media at 298.15 Acta. Ac united Ac 2018; 104: 277-283. DOI 10.3813/AAA.919170., 28Bhutra R, Sharma R, Sharma AK. Synthesis, Characterization and fungicidal activities of Cu (II) surfactants derived from groundnut and mustard oils treated at high temperatures. J Inst Chemists (India) 2018; 90(3): 66-80.]. containing compounds are able to enhance the performance of copper soaps. The organic compounds containing amino group play an important role in biology, as it constitutes the repeating unit of the polypeptide macromolecules. These results show that the Cu (II) soap-complexes of ligands are much more toxic than the ligands themselves [29Tank P, Sharma R, Sharma AK. Micellar features and various interactions of copper soap complexes derived from edible mustard oil in benzene at 303.15 K Curr. Phy Chem 2018; 8(1): 46-57.]. The enhanced activity of newly synthesized complexes as compared to those of the ligand can possibly be explained on the basis of chelate formation, the presence of donor atoms, basicity as well as the structural compatibility with molecular nature of the toxic moiety [30Bhutra R, Sharma R, Sharma AK. Fungicidal activities of Cu (II) soaps derived from various oils treated at high temperature for biomedical use. SAJ Biotechnol 2018; 5(103): 1-6.]. The enhanced biological activity of complexes is in accordance with the chelation theory. The results of ANOVA [31Sharma A K, Sharma R, Saxena M. (2018) Biomedical and antifungal application of Cu(II) soaps and its urea complexes derived from various oils. Open access J Trans Med res 2(2) 40-43.] for the antifungal activities for all soaps complexes are shown in Table 5. The predicted R2 was obserbed to be in reasonable agreement and closer to1.0. This confirms that the experimental data are satisfactory. The descriptive statics results shown in Table 6 confirm the satisfactory results in triplet [32Sharma AK, Sharma R, Gangwal A. Biomedical and fungicidal application of copper surfactants derived from pure fatty acid, Organic & Medicinal Chem. 2018 IJ 5(5): OMCIJ.MS.ID.555680, 1-4].
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Fig. (8) Antifungal activity of ligand soap and complex (methyl) for fungi Alternaria Alternata. |
In conclusion, it can be said that the appearance of enhanced activity may be due to synergistic mechanism i.e. the free ligands are less active but on complexation, show more activity in combination with copper (II) soaps. Thus it is evident that concentration plays a vital role in increasing the degree of inhibition. So fungicidal screening data revealed that at lower concentration, the inhibition of growth is less as compared to higher concentration.In all complexes, toxicity increases with the domination of methanol in the solvent mixture of methanol and benzene [40% methanol–benzene and 80% methanol–benzene]. Suggesting that complexes are more effectively playing their role in determining the growth of fungi in the domination of polar solvent in the ternary system: complex + methanol + benzene. Some recent studies about antimicrobial activities of newly synthesized 1, 4-benzothiazines possessing thiazolyl / imidazolyl moieties also support our findings.
Acknowledgment-The authors pay their sincere gratitude to, Principal, S. P. C. Govt. College, Ajmer, S.D. Govt. College Beawar, Rajasthan (India) for providing necessary research facilities to accomplish this study.
Not applicable.
No Animals/Humans were used for studies that are base of this research.
Not applicable.
The authors confirm that this article content has no conflict of interest.
Decleared none.
[1] | Sharma A K, Saxena M, Sharma R. Synthesis, spectroscopic and fungicidal studies of Cu (II) soaps derived from groundnut and sesame oils and their urea complexes Bulle Pure Appl Sci (2017) 36(2) 26-37 |
[2] | Bhati SK, Kumar A. Synthesis of new substituted azetidinoyl and thiazolidinoyl-1,3,4-thiadiazino (6,5-b) indoles as promising anti-inflammatory agents. Eur J Med Chem 2008; 43(11): 2323-30. [http://dx.doi.org/10.1016/j.ejmech.2007.10.012] [PMID: 18063224] |
[3] | Rashmi S, Arun K S. Natural Edible Oils: Comparative Health Aspects Of Sesame, Coconut, Mustard (Rape Seed) and Groundnut (Peanut) A Biomedical Approach. Biomed J Sci & Tech Res; 2017: 1(5) [http://dx.doi.org/10.26717/BJSTR.2017.01.000441] |
[4] | Tank P, Sharma AK, Sharma R. Thermal behaviour and kinetics of copper (II) soaps and complexes derived from mustard and soyabean oil. J Anal Pharm Res 2017; 4(2): 1-5. [http://dx.doi.org/10.15406/japlr.2017.04.00102] |
[5] | Sharma AK, Saxena M, Sharma R. Ultrasonic studies of Cu (II) soaps derived from mustard and soybean oils. J Pure Appl Ultrason 2017; 39(3): 92-9. |
[6] | Tank P, Sharma R, Sharma AK. Studies of Ultrasonic and acoustic parameters of complexes derived from Copper (II) surfactant of mustard oil with N and S atoms containing ligands in non- aqueous media (benzene) at 303.15 K. J. Acous Soc Ind 2017; 44(2): 87-99. |
[7] | Bhutra R, Sharma R, Sharma AK. Viscometric and CMC studies of Cu(II) surfactants derived from untreated and treated groundnut and mustard oils in non-aqueous solvent at 298.15 K J. Inst Chemists (India) 2017; 90: 29-47. |
[8] | Tank P, Sharma R, Sharma AK. A pharmaceutical approach & Antifungal activities of copper soaps with their N & S donor complexes derived from mustard and soyabean oils. Glob. J Pharmaceu. Sci 2017; 3(4): 1-6. [http://dx.doi.org/10.19080/GJPPS.2017.03.555619] |
[9] | Kumar A, Rajput CS. Synthesis and anti-inflammatory activity of newer quinazolin-4-one derivatives. Eur J Med Chem 2009; 44(1): 83-90. [http://dx.doi.org/10.1016/j.ejmech.2008.03.018] [PMID: 18501478] |
[10] | Sharma A, K, Saxena M, Sharma R. (2018) Synthesis, Spectroscopic and biocidal activities of environmentally safe agrochemicals. J Biochem. tech. 7(3) 1139-47 |
[11] | Alananbeh K, Al-Qodah Z, Amira El-Adly A, Al Refaee W. Impact of Silver Nanoparticles on Bacteria Isolated from Raw and Treated Wastewater in Madinah, KSA. Arab J Sci Eng 2016; 1-9. |
[12] | Alananbeh K, Al-Qodah Z, El-Adly Amira, Al Refaee A. W., Antifungal effect of silver nanoparticles on selected fungi isolated from raw and waste water. Indian J Pharm Sci 2017; 79(4): 559. |
[13] | Khan S, Sharma R, Sharma AK. Antifungal activities of copper surfactants derived from neem (AzadirectaIndica) and Karanj (Pongamiapinnata) oils: A pharmaceutical application. Glob J Pharmaceu Sci 2017; 3(4): 1-6. |
[14] | Mahajan K, Swami M, Singh RV. Microwave synthesis, spectral studies, antimicrobial approach, and coordination behavior of antimony(III) and bismuth(III) compounds with benzothiazoline,2009; 35: 179-80. Russ. J. Coord. Chem. 35(2009)179-180;https://DOI: 10.1134/S1070328409030038 |
[15] | Garg BS, Kumar DN. Spectral studies of complexes of nickel (II) with tetradentate schiff bases having N2O2 donor groups, Spectrochim. Acta 59A (2003): 229-234; https://DOI:10.1016/S1386-1425(02)00142-7 |
[16] | Sharma S, Sharma R, Sharma AK. Synthesis, Characterization, and thermal degradation of Cu (II) Surfactants for sustainable green chem. Asian J Green Chem 2017; 2(2): 129-40. [http://dx.doi.org/10.22631/ajgc.2017.95559.1015] |
[17] | Sharma AK, Sharma S, Sharma R. Thermal degradation of Cu (II) metallic soaps and their characterizations. A pharmaceutical application chronicles of pharmaceutical science 2017; 1(5): 312-19. |
[18] | Sharma S, Sharma R, Heda LC, Sharma AK. Kinetic parameters and Photo Degradation studies of copper soap derived from soybean oil using ZnO as a photo catalyst in solid and solution phase. J Inst Chemists (India) 2017; 89(4): 119-36. |
[19] | Khan S, Sharma R, Sharma AK. Ultrasonic studies of Cu (II) Soap derived from seed oil of Pongamiapinnata(Karanj), in non-aqueous binary and ternary systems at 298.15K. Malasian J Chem 2017; 19(2): 99-110. |
[20] | Bhutra R, Sharma R, Sharma AK. Comparative studies of treated & untreated oils as Cu (II) surfactants“ISBN978-3-659-83122-5 2017. |
[21] | Saxena M, Sharma R, Sharma AK. Micellar Features of Cu (II) surfactants derived from edible oils 2017. |
[22] | Mishra AP, Mishra RK, Shrivastava SP. Structural and antimicrobial studies of coordination compounds of VO(II), Co(II), Ni(II) and Cu(II) with some Schiff bases involving 2-amino-4-chlorophenol, J Serb Chem Soc 2009; 79: 523-35 |
[23] | Raval JP, Desai KG, Desai KR. Microwave synthesis, characterization and antimicrobial study of new pyrazolyl-oxopropyl-quinazolin-4(3H)-one derivatives. J Saudi Chem Soc 2011; 16(4): 387-93. [http://dx.doi.org/10.1016/j.jscs.2011.02.003] |
[24] | Chandra S, Jain D, Sharma AK, Sharma P. Coordination modes of a schiff base pentadentate derivative of 4-aminoantipyrine with cobalt(II), nickel(II) and copper(II) metal ions: synthesis, spectroscopic and antimicrobial studies. Molecules 2009; 14(1): 174-90. [http://dx.doi.org/10.3390/molecules14010174] [PMID: 19127246] |
[25] | Sharma AK, Saxena M, Sharma R. Acoustic studies of copper soap- urea complexes derived from groundnut and seasam oils. J Phy Studies 2017; 21(4): 4601-6. |
[26] | Sharma AK, Saxena M, Sharma R. Ultrasonic studies of Cu (II) Soaps derived from Groundnut and Sesame oils. Tenside Surf Det 2017; 55(2): 127-34. [http://dx.doi.org/10.3139/113.110544] |
[27] | Khan S, Sharma R, Sharma AK. (2018) Acoustic studies and other acoustic parameters of Cu(II) Soap derived from non- edible Neem oil (Azadirectaindica), in Non-aqueous media at 298.15 Acta. Ac united Ac 2018; 104: 277-283. DOI 10.3813/AAA.919170. |
[28] | Bhutra R, Sharma R, Sharma AK. Synthesis, Characterization and fungicidal activities of Cu (II) surfactants derived from groundnut and mustard oils treated at high temperatures. J Inst Chemists (India) 2018; 90(3): 66-80. |
[29] | Tank P, Sharma R, Sharma AK. Micellar features and various interactions of copper soap complexes derived from edible mustard oil in benzene at 303.15 K Curr. Phy Chem 2018; 8(1): 46-57. |
[30] | Bhutra R, Sharma R, Sharma AK. Fungicidal activities of Cu (II) soaps derived from various oils treated at high temperature for biomedical use. SAJ Biotechnol 2018; 5(103): 1-6. |
[31] | Sharma A K, Sharma R, Saxena M. (2018) Biomedical and antifungal application of Cu(II) soaps and its urea complexes derived from various oils. Open access J Trans Med res 2(2) 40-43. |
[32] | Sharma AK, Sharma R, Gangwal A. Biomedical and fungicidal application of copper surfactants derived from pure fatty acid, Organic & Medicinal Chem. 2018 IJ 5(5): OMCIJ.MS.ID.555680, 1-4 |