Structural Characterization, In Silico Studies and In Vitro Antibacterial Evaluation of a Furanoflavonoid from Karanj

Abstract

Pongamia pinnata, popularly referred to as Karanj, is a multipurpose legume well known for its traditional and pharmacological properties with an efficient remedy for human health problems. Karanjin, a furanoflavonoid (3-methoxy-2-phenylfuro [2,3-h] chromen-4-one), is the main constituent of Karanj seeds with important biological attributes. The present investigation was aimed at standardizing a process for the isolation of karanjin from seed oil with an emphasis on achieving a higher yield of the pure compound. Structural elucidation and characterization were carried out via HRMS, Fourier transform infrared spectroscopy, X-rays diffraction, NMR, Raman spectroscopy, and thermogravimetric studies. The optimized geometry of the karanjin compound has been determined by a density functional theory and compared with experimental values, which are in excellent agreement. The potency of karanjin against pathogenic indicators was evaluated and confirmed by Raman scattering and field emission scanning electron microscopy imaging. The physicochemical parameters of karanjin were determined by in silico drug likeness properties, and molecular docking was also performed, which revealed the potential of karanjin as a highly functionalized and medicinally useful compound. From the docked conformations, the carbonyl group, 3-methoxy group, and oxygen atom in the C ring of the karanjin molecule were found to be biologically important for hydrogen bond formation with common bacterial enzymes involved in fatty acid biosynthesis. The mode of antibacterial action of karanjin revealed the complex patterns of probable cell wall disruption. This is the first report with regard to karanjin characterization and theoretical calculations of a density functional theory and its utility as a potential pharmacophore depicting an antibacterial property using Raman spectroscopy and docking studies.

Key words

Pongamia pinnata - Fabaceae - antibacterial activity - furanoflavonoid - Karanj - Raman spectroscopy

• References

• 1 Naumann D. FT-infrared and FT-Raman spectroscopy in biomedical research. Appl Spectrosc Rev 2001; 36: 239-298
• 2 Katekhaye SD, Kale MS, Laddha KS. A simple and improved method for isolation of karanjin from Pongamia pinnata Linn. seed oil. Indian J Nat Prod Resour 2012; 3: 131-134
• 3 Vismaya W, Eipeson S, Manjunatha JR, Srinivas P, Kanya TCS. Extraction and recovery of karanjin: A value addition to karanja (Pongamia pinnata) seed oil. Ind Crop Prod 2010; 32: 118-122
• 4 Prabhu TM, Devakumar C, Sastry VRB, Agrawal DK. Quantification of karanjin using high performance liquid chromatography in raw and detoxified karanj (Pongamia Glabra Vent) seed cake. Asian-Australas J Anim Sci 2002; 15: 416-420
• 5 Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE, Robb MA, Cheeseman JR, Montgomery jr. JA, Vreven T, Kudin KN, Burant JC, Millam JM, Iyengar SS, Tomasi J, Barone V, Mennucci B, Cossi M, Scalmani G, Rega N, Petersson GA, Nakatsuji H, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Klene M, Li X, Knox JE, Hratchian HP, Cross JB, Bakken V, Adamo C, Jaramillo J, Gomperts R, Stratmann RE, Yazyev O, Austin AJ, Cammi R, Pomelli C, Ochterski JW, Ayala PY, Morokuma K, Voth GA, Salvador P, Dannenberg JJ, Zakrzewski VG, Dapprich S, Daniels AD, Strain MC, Farkas O, Malick DK, Rabuck AD, Raghavachari K, Foresman JB, Ortiz JV, Cui Q, Baboul AG, Clifford S, Cioslowski J, Stefanov BB, Liu G, Liashenko A, Piskorz P, Komaromi I, Martin RL, Fox DJ, Keith T, Al-Laham MA, Peng CY, Nanayakkara A, Challacombe M, Gill PMW, Johnson B, Chen W, Wong MW, Gonzalez C, Pople JA. Gaussian 03, Revision C.02. Wallingford, CT: Gaussian, Inc.; 2004
• 6 Sheldrick GM. SADABS. Göttingen, Germany: University of Göttingen; 2004
• 7 Sheldrick GM. SHELXL97 Program for crystal structure refinement. Göttingen, Germany: University of Göttingen; 1997
• 8 Dolomanov OV, Bourhis LJ, Gildea RJ, Howard JAK, Puschmann H. OLEX2: a complete structure solution, refinement and analysis program. J Appl Cryst 2009; 42: 339-341
• 9 Gill PS, Sauerbrunn SR, Crowe BS. High resolution thermogravimetry. J Therm Anal 1992; 38: 255-266
• 10 Cañamares MV, Lombardi JR, Leona M. Raman and surface enhanced Raman spectra of 7-hydroxylfavone and 3′,4′-dihydroxyflavone. e-PS 2009; 6: 81-88
• 11 Corredor C, Teslova T, Cañamares MV, Chen Z, Zhang J, Lombardi JR, Leona M. Raman and surface-enhanced Raman spectra of chrysin, apigenin and luteolin. Vib Spectrosc 2009; 49: 190-195
• 12 Lipinski CA, Lombardo F, Dominy BW, Feeney PJ. Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings. Adv Drug Deliv Rev 1997; 23: 4-25
• 13 Ayati A, Falahati M, Irannejad H, Emami S. Synthesis, in vitro antifungal evaluation and in silico study of 3-azolyl-4-chromanone phenyl hydrazones. Daru 2012; 20: 46
• 14 Dundas J, Ouyang Z, Tseng J, Binkowski A, Turpaz Y, Liang J. CASTp: computed atlas of surface topography of proteins with structural and topographical mapping of functionally annotated residues. Nucleic Acids Res 2006; 34: 116-118
• 15 Volkamer A, Kuhn D, Grombacher T, Rippmann F, Rarey M. Combining global and local measures for structure-based druggability predictions. J Chem Inf Model 2012; 52: 360-372
• 16 Yang B, Kotani A, Arai K, Kusu F. Estimation of the antioxidant activities of flavonoids from their oxidation potentials. Anal Sci 2001; 17: 599-604
• 17 Cowan MM. Plant products as antimicrobial agents. Clin Microbiol Rev 1999; 12: 564-586
• 18 Fowler Z, Baron GM, Panepinto JG, Koffas MA. Melanization of flavonoids by fungal and bacterial laccase. Yeast 2011; 28: 181-188
• 19 Kharb R, Shama P, Yar MS. Pharmacological significance of triazole scaffold. J Enzyme Inhib Med Chem 2011; 26: 1-21
• 20 Xu HX, Lee SF. Activity of plant flavonoids against antibiotic-resistant bacteria. Phytother Res 2001; 15: 39-43
• 21 Jeong MR, Park PB, Kim DH, Jang YS, Jeong HS, Choi SH. Essential oil prepared from Cymbopogon citratus exerted an antimicrobial activity against plant pathogenic and medical microorganisms. Mycobiology 2009; 37: 48-52
• 22 Movasaghi Z, Rehman S, Rehman IU. Raman spectroscopy of biological tissues. Appl Spectrosc Rev 2007; 42: 493-541
• 23 Maquelin K, Kirschner C, Choo-Smith LP, van den Braak N, Endtz HP, Naumann D, Puppels GJ. Identification of medically relevant microorganisms by vibrational spectroscopy. J Microbiol Methods 2002; 51: 255-271
• 24 Dutta RK, Sharma PK, Pandey AC. Assessing the conformational and cellular changes of ZnO nanoparticles impregnated Escherichia coli cells through molecular fingerprinting. Adv Mat Lett 2011; 2: 268-275
• 25 Kesari V, Das A, Rangan L. Physico-chemical characterization and antimicrobial activity from seed oil of Pongamia pinnata, a potential biofuel crop. Biomass Bioenergy 2010; 34: 108-115
• 26 Ghosh S, Indukuri K, Bondalapati S, Saikia AK, Rangan L. Unveiling the mode of action of antibacterial labdane diterpenes from Alpinia nigra (Gaertn.) B. L. Burtt seeds. Eur J Med Chem 2013; 66: 101-105