Antioxidant Capacity and Phenolic Content of Different Solvent Extracts from Banana (Musa paradisiaca) and Mustai (Rivea hypocrateriformis)

Nataraj Loganayaki,Dharmar Rajendrakumaran,Sellamuthu Manian 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.5

In the present study, chloroform, acetone, and methanol extracts from stem and flower of banana (Musa paradisiaca) and leaves, stem, and flowers of mustai (Rivea hypocrateriformis) were evaluated for their in vitro antioxidant activity using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), 2,2'azinobis (3-ethylbenzothiozoline-6-sulfonic acid) diammonium salt (ABTS•+), iron chelation, and antihemolytic activity. Among the solvents used, methanol gave the maximum yield in banana, whereas in night glory acetone was reported to having higher extractive value. The total phenolic content was also higher in these extracts. The antioxidant potential of the extracts was well established with their DPPH• and ABTS•+ radical scavenging activities and ferric reducing antioxidant capacity. The potential of multiple antioxidant activity of samples can be further evidenced by inhibition of reactive oxygen mediated erythrocyte cell lysis and metal ion chelating activity. However, this is the first report on the antioxidant property of mustai and this plant is having excellent antioxidant potential over banana. In conclusion, the results implied that the leaves, stem, and flowers of banana, and mustai could be considered as health supplements and nutraceuticals/functional foods.

In vitro Antioxidant Properties of Indigenous Underutilized Fruits

Nataraj Loganayaki,Sellamuthu Manian 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.3

In the present study, in vitro antioxidant and free radical scavenging capacity of methanol extracts from 10 underutilized fruits viz., Syzygium cumini, Murraya koenigii, Coccinia grandis, Opuntia dillenii, Carissa carandus, Kirganalia reticulata, Canthium parviflorum,Lantana camara, Alangium lamarckii, and Morus alba were evaluated using established in vitro models such as ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH•), 2,2'azinobis(3-ethylbenzothiozoline-6-sulfonic acid) diammonium salt (ABTS), hydroxyl radical (OH•), nitric oxide radical (NO•), super oxide radical (O2• −) scavenging, and metal chelating activities. All the fruit extracts contained substantial concentration of total phenolics, tannins, and flavonoids. The extracts of O. dillenii, M. koenigii, K. reticulata, L. camara, and M. alba registered higher activity in DPPH•, ABTS• +, and FRAP assays. Phenolic content of these fruits is significantly correlated with antioxidant capacity. Interestingly, all the extracts showed considerable nitric oxide, super oxide, and hydroxyl radical scavenging activities in a dose dependant manner when compared with the standard butylatedhydroxyl anisole (BHA). Our findings revealed that these underutilized fruits have potential as good sources of natural antioxidant/nutraceutical compounds.

Evaluation of Edible Flowers of Agathi (Sesbania grandiflora L. Fabaceae) for in vivo Anti-inflammatory and Analgesic, and in vitro Antioxidant Potential

Nataraj Loganayaki,Nandhagopalan Suganya,Sellamuthu Manian 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.2

The methanol extract from flowers of agathi (Sesbania grandiflora L. Fabaceae) was evaluated for their in vitro antioxidant and cytotoxic activities, and in vivo anti-inflammatory and antinociceptive activities in several experimental models. The extract has sustainable concentrations of dietary polyphenolics, tannins, and flavonoids. The extract exhibited maximum radical scavenging activity on nitric oxide, superoxide, and hydroxyl radical and these values were significantly (p<0.05) higher over positive standards butylated hydroxyanisole and butylated hydroxytolune. The extract also exhibited potential cytotoxic activity against human cervical cancer cell line HeLa (IC50value of 0.13 mg/mL). Further, the methanol extracts showed significant inhibitory activity against inflammation (carrageenan and cotton pellet induced models) and on a pain model (hot plate test). The inhibitory values are comparable with positive standards. Owing to these properties, agathi flowers can be used as a potential source of natural nutraceutical food supplement.

In-situ deposition of iron oxide nanoparticles on polyacrylonitrile-based nanofibers by chemico-thermal reduction method.

Nataraj, S K,Kim, Bo-Hye,Yang, Kap Seung,Woo, Hee-Gweon American Scientific Publishers 2010 Journal of Nanoscience and Nanotechnology Vol.10 No.5

<P>Polyacrylonitrile (PAN)-based nanocomposite fibers were prepared by co-precipitation of different amounts of Fe(II) and Fe(III) in an alkaline medium to get iron oxide impregnated nanofibers. Nanofibers web were prepared from blend solution of PAN containing different concentrations (1, 2 and 3 wt%) of ferrous (Fe2+)/ferric (Fe3+) solution in the 1:2 molar ratio in an effort to further improvement of the porosity and thereby, electrical properties. Electrospun fibers containing various concentrations of iron salts were then treated with KOH solution to produce nanosized magnetite particles in situ within the PAN nanofibers by precipitating Fe2+ ions or mixture of Fe2+ and Fe3+ ions. Such nanoscale particles homogeneously dispersed in PAN nanofibers to form the three-dimensional network structure. The homogeneously dispersed nanoparticles of iron oxide in and on the PAN carbon nanofibers produced the network structure of reasonably well-aligned configuration. Composite nanofibers morphologies and surface properties were discussed utilizing the combined techniques viz., field emission scanning electron microscope (FE-SEM), particle size analyzer, surface area and pore size distribution measurements.</P>

Effect of added nickel nitrate on the physical, thermal and morphological characteristics of polyacrylonitrile-based carbon nanofibers

Nataraj, S.K.,Kim, B.H.,Yun, J.H.,Lee, D.H.,Aminabhavi, T.M.,Yang, K.S. Elsevier 2009 Materials science and engineering B. Advanced Func Vol.162 No.2

<P><B>Abstract</B></P><P>Porous carbon nanofibers (CNFs) with enhanced physical, thermal and morphological properties are desirable in many areas like catalyst support in fuel cells and supercapacitors as electrode material. This research addresses the effect of added nickel nitrate in 1, 3 and 5wt% into polyacrylonitrile (PAN) precursor solution to produce CNF webs using electrospinning method. Based on the quantitative data obtained from field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM) images, we can notice that CNFs were formed with diameters in the size range of 100–300nm after carbonization at 1000°C. Fiber diameter of the random CNFs was decreased by increasing the nickel nitrate contents along with dramatic improvements in porosity and specific surface areas. This study indicated that the optimal nickel nitrate concentration of 5wt% has produced CNFs with enhanced physical and thermo-chemical properties. The high resolution X-ray diffraction (HR-XRD) showed an increase in intensity of 002 peak of the CNFs due to the catalytic function of nickel oxide in the carbonized web and these observations are in agreement with the thermal gravimetric data.</P>

Sequence Dependent Binding Modes of the ΔΔ- and ΛΛ-binuclear Ru(II) Complexes to poly[d(G-C)2] and poly[d(A-T)2]

Nataraj Chitrapriya,Raeyeong Kim,장윤정,조대원,한성욱,김석규 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.7

The binding properties and sequence selectivities of ΔΔ- and ΛΛ-[μ-Ru2(phen)4(bip)]4+ (bip = 4,4'-biphenylene (imidazo [4,4-f][1,10]phenanthroline) complexes with poly[d(A-T)2] and poly[d(G-C)2] were investigated using conventional spectroscopic methods. When bound to poly[d(A-T)2], a large positive circular dichroism (CD) spectrum was induced in absorption region of the bridging moiety for both the ΔΔ- and ΛΛ-[μ- Ru2(phen)4(bip)]4+ complexes, which suggested that the bridging moiety sits in the minor groove of the polynucleotide. As luminescence intensity increased, decay times became longer and complexes were wellprotected from the negatively charged iodide quencher compared to that in the absence of poly[d(A-T)2]. These luminescence measurements indicated that Ru(II) enantiomers were in a less polar environment compared to that in water and supported by minor groove binding. An angle of 45° between the molecular plane of the bridging moiety of the ΔΔ-[μ-Ru2(phen)4(bip)]4+ complex and the local DNA helix axis calculated from reduced linear dichroism (LDr) spectrum further supported the minor groove binding mode. In the case of ΛΛ- [μ-Ru2(phen)4(bip)]4+ complex, this angle was 55°, suggesting a tilt of DNA stem near the binding site and bridging moiety sit in the minor groove of the poly[d(A-T)2]. In contrast, neither ΔΔ- nor ΛΛ-[μ-Ru2(phen)4- (bip)]4+ complex produced significant CD or LDr signal in the absorption region of the bridging moiety. Luminescence measurements revealed that both the ΔΔ- and ΛΛ-[μ-Ru2(phen)4(bip)]4+ complexes were partially accessible to the I− quencher. Furthermore, decay times became shorter when bis-Ru(II) complexes bound to poly[d(G-C)2]. These observations suggest that both the ΔΔ- and ΛΛ-[μ-Ru2(phen)4(bip)]4+ complexes bind at the surface of poly[d(G-C)2], probably electrostatically to phosphate group. The results indicate that ΔΔ- and ΛΛ-[μ-Ru2(phen)4(bip)]4+ are able to discriminate between AT and GC base pairs.

Electrospun Nanocomposite Fiber Mats of Zinc-Oxide Loaded Polyacrylonitrile

Nataraj, S.K.,Kim, B.H.,Yun, J.H.,Lee, D.H.,Aminabhavi, T.M.,Yang, K.S. Korean Carbon Society 2008 Carbon Letters Vol.9 No.2

We have demonstrated the feasibility of using electrospinning method to fabricate long and continuous composite nanofiber sheets of polyacrylonitrile (PAN) incorporated with zinc oxide (ZnO). Such PAN/ZnO composite nanofiber sheets represent an important step toward utilizing carbon nanofibers (CNFs) as materials to achieve remarkably enhanced physico-chemical properties. In an attempt to derive these advantages, we have used a variety of techniques such as field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and high resolution X-ray diffraction (HR-XRD) to obtain quantitative data on the materials. The CNFs produced are in the diameter range of 100 to 350 nm after carbonization at $1000^{\circ}C$. Electrical conductivity of the random CNFs was increased by increasing the concentration of ZnO. A dramatic improvement in porosity and specific surface area of the CNFs was a clear evidence of the novelty of the method used. This study indicated that the optimal ZnO concentration of 3 wt% is enough to produce CNFs having enhanced electrical and physico-chemical properties.

Antioxidant Activity of Two Traditional Indian Vegetables: Solanum nigrum L. and Solanum torvum L.

Nataraj Loganayaki,Perumal Siddhuraju,Sellamuthu Manian 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.1

In the present study, chloroform, acetone, and methanol extracts of Solanum torvum and Solanum nigrum leaves and fruit were evaluated for their in vitro antioxidant activity using ferric reducing antioxidant power, 2,2-diphenyl-1-picryl-hydrazyl (DPPH), ABTS•+, iron chelation,and antihemolytic activity. Among the various solvents used, the maximum yield was obtained in chloroform followed by acetone and methanol. The total phenolics were also significantly higher in the chloroform extracts and the in vitro antioxidant activity was shown to be highly dependant on the total phenolic content (p<0.01). The DPPH• and 2,2'azinobis(3-ethylbenzothiozoline-6-sulfonic acid) diammonium salt (ABTS) cation radical scavenging activities were well proved with the ferric reducing antioxidant capacity of the extracts. The potential of multiple antioxidant activity of samples can be further evidenced by inhibition of reactive oxygen mediated erythrocyte cell lysis and metal ion chelating activity. In conclusion, the results presented here implied leaves and fruits of S. torvum and S. nigrum could be considered as health supplements and nutraceuticals/functional foods.

A new mixed finite element method for Burgers' equation

Neela Nataraj,Ambit Kumar Pany,Sangita Singh 한국전산응용수학회 2007 Journal of applied mathematics & informatics Vol.23 No.1

In this paper, an H1-Galerkin mixed finite element method is used to approximate the solution as well as the flux of Burgers’ equation. Error estimates have been derived. The results of the numerical experiment show the efficacy of the mixed method and justifies the theoretical results obtained in the paper.

Sequence Dependent Binding Modes of the ΔΔ- and ΛΛ-binuclear Ru(II) Complexes to poly[d(G-C)₂] and poly[d(A-T)₂]

Chitrapriya, Nataraj,Kim, Raeyeong,Jang, Yoon Jung,Cho, Dae Won,Han, Sung Wook,Kim, Seog K. Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.7

The binding properties and sequence selectivities of ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ (bip = 4,4'-biphenylene (imidazo [4,4-f][1,10]phenanthroline) complexes with $poly[d(A-T)_2]$ and $poly[d(G-C)_2]$ were investigated using conventional spectroscopic methods. When bound to $poly[d(A-T)_2]$, a large positive circular dichroism (CD) spectrum was induced in absorption region of the bridging moiety for both the ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complexes, which suggested that the bridging moiety sits in the minor groove of the polynucleotide. As luminescence intensity increased, decay times became longer and complexes were well-protected from the negatively charged iodide quencher compared to that in the absence of $poly[d(A-T)_2]$. These luminescence measurements indicated that Ru(II) enantiomers were in a less polar environment compared to that in water and supported by minor groove binding. An angle of $45^{\circ}$ between the molecular plane of the bridging moiety of the ${\Delta}{\Delta}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complex and the local DNA helix axis calculated from reduced linear dichroism ($LD^r$) spectrum further supported the minor groove binding mode. In the case of ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complex, this angle was $55^{\circ}$, suggesting a tilt of DNA stem near the binding site and bridging moiety sit in the minor groove of the $poly[d(A-T)_2]$. In contrast, neither ${\Delta}{\Delta}$-nor ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complex produced significant CD or $LD^r$ signal in the absorption region of the bridging moiety. Luminescence measurements revealed that both the ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complexes were partially accessible to the $I^-$ quencher. Furthermore, decay times became shorter when bis-Ru(II) complexes bound to $poly[d(G-C)_2]$. These observations suggest that both the ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complexes bind at the surface of $poly[d(G-C)_2]$, probably electrostatically to phosphate group. The results indicate that ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ are able to discriminate between AT and GC base pairs.