ABSTRACT
This study evaluated the anti-oxidant and anti-diabetic potential of Caralluma fimbriata (CF) in 28-days rat modelling trial. Diabetes is a chronic disorder characterized by elevated blood glucose levels and insulin resistance and cause microvascular and macrovascular issues. Caralluma fimbriata was evaluated for its nutritional composition along with anti-oxidant potential of CF powder (CFP) and CF extract (CFE) using total phenolic contents (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power (FRAP) assays. Furthermore, anti-diabetic potential was computed by dividing rats into four groups of 5 individuals each. Rats of Group I was non-diabetic and no supplementation was given while rats of group II were diabetic and no supplementation was given. While group III and group IV rats were diabetic and received CFP and CFE supplementation respectively. CF powder's TPC, and DPPH and FRAP activity were observed maximum at 44.17 ± 0.006 (µgFe/g) in water, 68.75 ± 0.49 (µgFe/g) in acetone and 800.81 ± 0.99 (µgFe/g) in hexane. Supplementation of CFP and CFE reduced blood glucose effectively i.e. (125.00 ± 4.04 and 121.00 ± 4.49 mg/dL, respectively). Moreover, the consumption of C. fimbriata can be helpful in the management of diabetes mellitus due to its glucose lowering potential, anorexic effects, anti-oxidant potential and α-amylase inhibition.
ABSTRACT
Five covalently bonded polyoxometalate (POM)-porphyrin hybrids were synthesized by reacting the Wells-Dawson type polyoxometalate [N(C4H9)4]5H4P2W15V3O62 with five tris-functionalized porphyrins containing different numbers of tris groups at different peripheral positions. These hybrids were thoroughly characterized using elemental analysis, NMR (1H, 31P, and 51V), mass spectrometry (ESI-MS, MALID-TOF-MS), FT-IR, UV-Vis, and fluorescence spectroscopies. The results proved that different quantities (one, two, and three) of the vanadium-capped Wells-Dawson type metal-oxide cluster P2W15V3O629- can be grafted onto a porphyrin moiety via covalent bonding with different orientations, depending on the number and position of peripheral functional groups on the porphyrin. Interestingly, remarkable fluorescence quenching (60% in 3Py-P@1POM, 75% in trans-2PyP@2POM, 80% in cis-2PyP@2POM, 85% in cis-2PhP@2POM, and 55% in 1Py-P@3POM, as compared to the fluorescence intensity of their corresponding porphyrin precursor) was observed under excitation (λexc = 328 nm), indicating electron transfer from the porphyrin moiety to the POM moiety through covalent linkage.
ABSTRACT
Herein, new all-inorganic transparent composite films with the formula (Zn2Al-LDH/{Mo132-Ac})n have been fabricated by a layer-by-layer method using the exfoliated Zn2Al-LDH monolayer nanosheets and Keplerate-type macroanion {Mo132-Ac}. They were characterized by UV-vis absorption spectroscopy, SEM, AFM, and XPS techniques. The Z-scan measurements, which were conducted under laser irradiation at a wavelength of 532 nm, a pulse width of 6 ns, a repetition rate of 10 Hz, and the light intensity at a focus E0 of 10 µJ, revealed that all the films had notable saturated absorption and self-defocusing effect with a large third-order optical nonlinear susceptibility χ(3). With an increase in the number of layers (i.e., n) corresponding to the increase in the thickness of the films, the third-order nonlinear absorption ß and refractive effects of the films were improved (i.e., the χ(3) value was up to 1.99 × 10-11 esu when n = 24); this implied that the NLO responses could be modified by fine-tuning the thickness of the composite films to meet the demands of different devices.
ABSTRACT
Composite films with the general formula (POM/CuTAPc)n derived from water-soluble Keggin-type polyoxometalates (POMs = H5PMo10V2O40, H4SiW12O40, H3PMo12O40 and H3PW12O40) and water-insoluble 4,9,16,23-copper tetraaminophthalocyanine (denoted CuTAPc) are successfully fabricated by a layer-by-layer self-assembly technique and systematically characterized. The structure of the polyoxometalate anions in the multilayers is kept intact; the deposition amounts of POM and CuTAPc remain constant in every adsorption cycle of the composite film assembly process. The nonlinear optical properties of the composite films were studied by a Z-scan technique at a wavelength of 532 nm and a pulse width of 7 ns. The results not only show that the composite films exhibit notable optical nonlinear self-defocusing behavior and a saturated absorption effect with the nonlinear optical absorption co-efficient ß, refractive index n2, and third-order NLO susceptibility χ(3) of the films increasing with the increase in number of layers of the films, but also reveal importantly that the discrepancy of LUMO levels between CuTAPc and POMs is proportional to their third-order NLO response.
Subject(s)
Copper/chemistry , Indoles/chemistry , Tungsten Compounds/chemistry , Water/chemistry , Isoindoles , Models, Molecular , Nonlinear Dynamics , Optical Phenomena , SolubilityABSTRACT
Composite films derived from the water-soluble Keplerate-type polyoxometalate (NH4)42[Mo132O372(CH3COO)30(H2O)72]·ca. 300H2O·ca. 10CH3COONH4 (denoted (NH4)42{Mo132}) and chloroform-soluble tetraphenylporphyrin perchlorate [H2TPP](ClO4)2 are successfully fabricated by a layer-by-layer self-assembly method and characterized by UV-vis spectroscopy and X-ray photoelectron spectroscopy (XPS). The structure of the {Mo132} and [H2TPP](2+) in the films remain intact in light of the results of UV-vis spectroscopy and XPS. UV-vis spectra measurements reveal that the amounts of deposition of {Mo132} and [H2TPP](2+) remain constant in every adsorption cycle in the composite films assembly process. Nonlinear optical properties of the composite films have been investigated by using the Z-scan technique at a wavelength of 532 nm and pulse width of 7 ns. The results show that the composite films have notable nonlinear saturated absorption and self-defocusing effects. The combination of {Mo132} with [H2TPP](2+) can result in composite films with remarkably enhanced optical nonlinearities. The interfacial charge transfer induced by laser from porphyrin to POM in the films is thought to play a key role in the enhancement of NLO response. The third-order NLO susceptibility χ((3)) of the composite films increases with the increase of film thickness.
