Selective antiviral activity of synthetic soluble l-tyrosine and l-dopa melanins against human immunodeficiency virus in vitro

Montefiori, David C.; Zhou, Ji

doi:10.1016/0166-3542(91)90037-r

Cited by 98 publications

(71 citation statements)

References 31 publications

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“…Natural melanin has been reported to have defense activity, protection function (Kollias et al 1991;Casadevall et al 2000) and metal chelating ability (Liu et al 2004). It could participate in physiological and pathological activities in human body (Riley 1997) and even become one of the treatment of Acquired Immure Deficiency Syndrome (AIDS) (Montefiori and Zhou 1991). Although the mechanisms of melanin in presenting these activities are complex, they are almost all related to free radical scavenging reactions (Różanowska et al 1999).…”

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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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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“…The latter makes it possible to determine the melanin type by the shape of EPR spectrum (Montefoiori, Zhou, 1991). The present study demonstrates that the eumelamin type pigments are synthesized at all the stages of H. illucens life cycle: prepupae, pupae, adult flies (dead flies), but in different quantities.…”

Section: Discussionmentioning

confidence: 57%

“…Our studies have shown that the antibacterial activity has melanin suspension in ethanol, which, apparently, due to the solubility of the melanin. Melanin is known to show bacteriostatic and antiviral effect (Montefoiori, Zhou, 1991;Martikyan, et al, 2015). It is well-known that the physico-chemical properties of eumelanin are essentially a function of its polymerization.…”

Section: Discussionmentioning

confidence: 99%

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Melanin properties at the different stages towards life cycle of the fly Hermetia illucens

Ушакова¹,

Донцов²,

Сакина³

et al. 2017

Ukr J Ecol

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Eumelanin type pigments are synthesized at all the stages of the life cycle of the fly Hermetia illucens: in the larvae, pre-pupae, pupae and adult flies (dead flies). The greatest content of melanin was recorded in the cuticles. Melanin was present not only in the cuticle, hence it remained in the cuticle after the emergence of the adult fly. It was also found in the insect body in a complex with lipids. In pupae, it is mostly lauric acid that was associated with melanin. Its proportion in the melanin-chitosan complex was 80%. The isolated melanin-chitosan complex of adult flies showed a wide range of antibacterial activity, inhibiting the growth of 21 out of the 25 of the test cultures. The melanin-chitosan complex of empty pupal membranes and alcohol suspension of pupal melanin inhibited twice as smaller number of test cultures and the above activity was absolutely in the pupal chitosan. The largest zone of growth inhibition was recorded with respect to Aspergillus niger, Candida albicans, salmonella, and Staphylococcus aureus. An alcohol suspension of pupal melanin inhibited the growth of 10 test cultures. In this case the greatest activity was shown in relation to Mycobacterium B5 and Acinetobacter sp. 1182.Key words: melanin; melanin-chitosan complex; Hermetia illucens; antibacterial activityThe fly Hermetia illucens is a typical member of Stratiomyidae, Diptera, Insecta (Linnaeus, 1758) is characterized by complete metamorphosis, including the main developmental stages as the egg, larva, pre-pupae, pupae, adult individual. It is only larvae that feed. Larvae are able to recycle different organic waste, using them as foraging substrates. This property determines the increased interest in these insects and the peculiarities of their biochemical composition in connection with the prospects of using insect meal in feed and food (. Although the chemical composition of the insect larvae varies with food substrate the fat content averages 30% (Diener, et al., 2011;St-Hilaire, et al., 2007;Gobbi, et al., 2013;Kalová, Borkovcová, 2013). Adult flies are equally fat. Our data demonstrate that fat content in dead flies accounts for 27%, and that in the larvae raised on wheat grains, 38%, and in prepupae, 32%. The large amount of fat in the body of the fly necessitates its antioxidant protection, which may be provided by melanin pigments. Melanins are nitrogen-containing compounds of irregular structure on the basis of phenol, which are the main pigment of insects. They create the dark-brown or brown coloration of insects, being created by the insects themselves, and become part of the cuticle, are present in the hemolymph, adipose body, and the intestinal tract (Nicolaus, 1968;Prota, 1992). The pigments have antioxidant, radio-and photo-protector, electron and ion-exchange properties (Dontsov, 2014;Ostrovsky, Dontsov, 1985). Natural melanin pigments show antibacterial and immune-modulation activity. They can form diverse complexes with proteins, various pharmacological agents, for instance, with antibiotics, which i...

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“…These physicochemical properties include strong light absorbance, unusual solubility, and remarkable redox properties. In addition, melanin has a number of healthful functions, such as antioxidant 6,7 and anti-HIV activity 8,9 . As a result, consumers are demanding to use melanin in the food industry as a safe natural colourant rather than a synthetic dye.…”

Section: Introductionmentioning

confidence: 99%

Properties of melanin from black tea leaves

Zhao¹

2015

ScienceAsia

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ABSTRACT:In this study, partial physicochemical properties and antioxidant activities of melanin from black tea leaves were studied. The results show that black tea melanin powder was dark tinted red and yellow (L * = 36.47, a * = 0.33,Black tea melanin solution exhibited strong optical absorbance in a wide UV-Vis spectral range and was relatively stable in the range of 25-100°C and under natural light. Furthermore, black tea melanin exhibited a strong superoxide-and hydroxyl-radical scavenging activity. Results of the present study indicated that black tea melanin could be potentially used as a food colourant with health benefits.

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Selective antiviral activity of synthetic soluble l-tyrosine and l-dopa melanins against human immunodeficiency virus in vitro

Cited by 98 publications

References 31 publications

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

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

Melanin properties at the different stages towards life cycle of the fly Hermetia illucens

Properties of melanin from black tea leaves

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