Isolation and characterization of melanin from Osmanthus fragrans’ seeds

Wang, Hengshan; Pan, Yingming; X, Tang; Huang, Zhiqing

doi:10.1016/j.lwt.2005.04.001

Cited by 119 publications

(106 citation statements)

References 13 publications

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“…The main function of melanin is considered to prevent skin damage by ultraviolet (UV) rays including in sunlight [1,2]. The excess accumulation of melanin or the absence of melanin production caused by aging, strass, and UV damages induces gray hairs, freckles, mottling, and senile lentigines [3].…”

Section: Melanin Biosynthesismentioning

confidence: 99%

Effect of quercetin derivatives on melanogenesis stimulation of melanoma cells

Mitsunaga

Yamauchi

2015

J Wood Sci

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Controlling melanogenesis is important for maintaining the good health and cosmetic appearance of a human body. This study aims to search the active compounds from natural products exhibiting the melanogenesis modulating activity and elucidate the mechanism underlying the observed activity. Two novel quercetin glycosideswere isolated and identified from Helminthostachys zeylanica roots 50 % ethanol extract. Compound 1 exhibited intracellular melanogenesis stimulatory activity, while 2 showed no effect even the structural similarity. To understand the structure-activity relationships, twelve quercetin glycosides and seven methylquercetins were synthesized from rutin as starting material. As the result of bioassay using synthesized nineteen quercetin derivatives in B16 melanoma cells, some quercetin-3-O-b-D-glucopyranosides stimulated the intracellular melanogenesis. On the other hand, synthesized 3-O-methylquercetin 12 and 3,4 0 ,7-Otrimethylquercetin 15 increased both intra and extracellular melanin contents with no cytotoxicity. Compoud 15 increased the phosphorylated p38 mitogen-activated protein kinase (MAPK) and microphthalmia-associated transcription factor (MITF) which regulates the expression of tyrosinase, TRP-1 and TRP-2. While 12 enhanced the expression of the melanogenic enzymes without involving the MITF, as evidenced by its lack of any stimulation of the expression of MITF and p-p38 MAPK. This result indicates that 12 may stimulate the expression of tyrosinase, TRP-1, and TRP-2 by stimulating currently unidentified transcriptional factors and/or by regulating the degradation of melanogenic enzymes.

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Section: Melanin Biosynthesismentioning

confidence: 99%

Effect of quercetin derivatives on melanogenesis stimulation of melanoma cells

Mitsunaga

Yamauchi

2015

J Wood Sci

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“…The structures of melanins have rarely been studied due to the difficulties in the isolation of melanins from natural sources and the poor solubility of the pigments. Melanins are insoluble in water and common organic solvents (such as hexane, chloroform, ethyl acetate, ethanol, methanol or acetone) (Sava et al, 2001a;Hsieh and Lien, 2012;Wang et al, 2006) and can be dissolved only in alkaline solutions. The range of available structural investigation methods is therefore limited.…”

Section: Introductionmentioning

confidence: 99%

Structural characterization of allomelanin from black oat

et al. 2016

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The brown to black coloration found in plants is due to the melanins, which have been relatively poorly investigated among the plant pigments. The aim of this work was to study the dark pigment extracted from the black oat hull with respect to composition and structure. Ultraviolet-visible (UV-Vis) spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) and Fourier transform infrared (FT-IR) spectroscopy were applied for the characterization of the pigment. UV-Vis spectroscopy revealed that the extracted material displayed the absorption profile typical of melanins. MALDI-TOF MS measurements demonstrated that oat melanin is a homopolymer built up from p-coumaric acid and consists mainly of low molecular weight (500-900 Da) oligomers of between 3 and 9 monomer units. The tetramer oligomer proved to be dominant. The results of the FT-IR analysis indicated that oat melanin is a fully conjugated aromatic system containing tetrasubstituted aromatic rings linked by C-C coupling. The in vitro preparation of melanin from p-coumaric acid by horseradish peroxidase was performed for comparison. The resulting polymer consisted of oligomers of 4 to 9 monomer units similarly to those in oat melanin. However the building blocks proved to be connected to each other via C-O-C linkages in contrast with the C-C linkages in oat melanin. This is the first demonstration of the structure of melanin originating from plants.

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“…Melanin originates from different nature sources, such as Osmanthus fragrans seeds (Wang et al 2006), Pleurotus cystidiosusand (Selvakumar et al 2008), and silky fowl (Tu et al 2009), and has been reported to have excellent free radicals scavenge activity. Squid ink melanin is the most typical melanin usually used as melanin standard with strong free radical protection activities (Menon and Haberman 1977).…”

Section: Introductionmentioning

confidence: 99%

Preparation of water-soluble melanin from squid ink using ultrasound-assisted degradation and its anti-oxidant activity

Guo

Chen

et al. 2013

J Food Sci Technol

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Water-soluble squid melanin fractions were firstly prepared using ultrasound-assistant degradation method under alkaline condition, which is optimized by response surface methodology. The processing melanin fractions were divided into different molecular weight (Mw) fractions by membrane separation (below 10 kDa, among 10-50 kDa and over 50 kDa). The AFM image and particle-size analysis showed monomer units of the melanin were destroyed, and huge polymers were degraded into smaller soluble particles after ultrasound. While, UV, IR and solid 13 C NMR spectra indicated that the basic structure of melanin fraction was still retained after ultrasound process. Further analysis showed soluble melanin fractions obtained in 0.5 and 1 M NaOH, with Mw above 10 kDa exhibited much higher in vitro antioxidant potency. The IC 50 of these fractions (IC 50 among 19-80 μg) on scavenging O 2¯i s more efficient than carnosine (IC 50 = 355 μg/ml.), a commercialized antioxidant. They (IC 50 mong 115-180 μg/ml) are as efficient as carnosine (IC 50 = 110 μg/ml) on scavenging OH. Our research has reported a novel method for preparation of water-soluble melanin fractions from squid ink, which could be a promising free radical scavenger from nature resource.Keywords Squid ink melanin . Water-soluble . Ultrasound . Structure, anti-oxidation Practical applicationWe developed a novel method using ultrasound processing to obtain water-soluble squid ink melanin under alkaline condition. Our results showed that soluble squid ink melanin fraction as a natural pigment, is a new free radical scavenger with a promising prospect. The excellent solubility can increase absorption and enhance utilization rate in vivo, providing a potential prospect for squid ink melanin products as a nature antioxidant.

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Isolation and characterization of melanin from Osmanthus fragrans’ seeds

Cited by 119 publications

References 13 publications

Effect of quercetin derivatives on melanogenesis stimulation of melanoma cells

Effect of quercetin derivatives on melanogenesis stimulation of melanoma cells

Structural characterization of allomelanin from black oat

Preparation of water-soluble melanin from squid ink using ultrasound-assisted degradation and its anti-oxidant activity

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