Isolation and characterization of melanic pigments derived from tea and tea polyphenols

Sava, Vasyl; Yang, Swen-Ming; Hong, Meng-Yen; Yang, Ping-Cheng; Huang, G. S.

doi:10.1016/s0308-8146(00)00258-2

Cited by 101 publications

(102 citation statements)

References 17 publications

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“…The melanin was isolated from oat hull and purified as described by Sava et al (2001b) with some modifications. The grounded oat hull (0.5 g) was suspended in 0.5 M NaOH (6 ml) in a screw-capped glass tube.…”

Section: Isolation and Purification Of The Oat Melaninmentioning

confidence: 99%

“…The precipitate was filtered off and washed with water. This dissolution and precipitation cycle was repeated three times (Sava et al, 2001b).…”

Section: Isolation and Purification Of The Oat Melaninmentioning

confidence: 99%

“…Characterization of the dark pigment obtained from oat hull The black pigment of the oat hull was isolated from the plant matrix by alkaline extraction. Purification was performed according to Sava et al (2001b). The multistep process started with acid hydrolysis to remove carbohydrates and proteins, which was followed by washing with organic solvents to remove lipids.…”

Section: Introductionmentioning

confidence: 99%

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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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Section: Isolation and Purification Of The Oat Melaninmentioning

confidence: 99%

“…The precipitate was filtered off and washed with water. This dissolution and precipitation cycle was repeated three times (Sava et al, 2001b).…”

Section: Isolation and Purification Of The Oat Melaninmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Structural characterization of allomelanin from black oat

et al. 2016

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“…Despite its health benefits, there are few studies using C. sinensis addressed to snake venom. Hung et al (2004) showed an antagonistic effect of 3 mg per mouse of melanin extracted from black tea (MEBT), an unhydrolyzed complex of tea polyphenols (Sava et al, 2001), against Agkistrodon contortrix laticinctus (broadbanded copperhead), Agkistrodon halys blomhoffii (Japanese mamushi), and Crotalus atrox (western diamondback rattlesnake) snake venoms, when administered i.p. immediately after venom administration in the same place of venom injection.…”

Section: Pharmacology 578mentioning

confidence: 99%

Antibothropic Action of Camellia sinensis Extract Against the Neuromuscular Blockade by Bothrops jararacussu Snake Venom and Its Main Toxin, Bothropstoxin-I

Oshima-Franco¹,

Rosa²,

Silva³

et al. 2012

Pharmacology

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“…During fermentation, the raw material turns from dark green to dark brown. The nature of the dark pigment of fermented O. stamineus leaves has not previously been investigated, but it is probably similar to the melanoidin from fermented Camelia sinensis leaves (black tea) (Sava et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Physicochemical characteristics and antioxidant activity of melanoidin pigment from the fermented leaves of Orthosiphon stamineus

Оленников¹,

Танхаева²

2012

Rev. bras. farmacogn.

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Abstract:The melanoidin pigment (OS-M) was isolated from fermented leaves of Orthosiphon stamineus Benth. (Lamiaceae), with a 0.37% yield (from dry plant weight), and characterised. OS-M is a phenolic polymer with a molecular weight of 4.4 kDa. Determination of basic physicochemical parameters using elemental analysis, functional group analysis, UV-Vis-and FTIR-spectroscopy of OS-M indicated that the isolated polymer was similar to typical melanoidins. Experimental data show that aromatic fragments dominate the OS-M structure, which also contains a small amount of aliphatic fragments.

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Isolation and characterization of melanic pigments derived from tea and tea polyphenols

Cited by 101 publications

References 17 publications

Structural characterization of allomelanin from black oat

Structural characterization of allomelanin from black oat

Antibothropic Action of Camellia sinensis Extract Against the Neuromuscular Blockade by Bothrops jararacussu Snake Venom and Its Main Toxin, Bothropstoxin-I

Physicochemical characteristics and antioxidant activity of melanoidin pigment from the fermented leaves of Orthosiphon stamineus

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