检索结果-南通市图书馆

In vitro polymerization of the dopamine-borate melanin precursor:A proof-of-concept regarding^(10)boron neutron-capture therapy for melanoma

引用

BIOCELL 2023年第4期47卷 919-928页

作者： JUAN C.STOCKERT SILVINA A.ROMERO MARCELO N.FELIX-POZZI ALFONSO BLÁZQUEZ-CASTRO Instituto de Oncología“Angel H.Roffo” Área InvestigaciónFacultad de MedicinaUniversidad de Buenos AiresBuenos AiresC1417DTBArgentina Centro Integrativo de Biología y Química Aplicada Universidad Bernardo O’HigginsSantiago8370854Chile Departamento de Micro y Nanotecnología Instituto de Nanociencias y NanotecnologíaCentro Atómico ConstituyentesComisión Nacional de Energía AtómicaBuenos AiresCP 1650Argentina Departamento de Biología Universidad Autónoma de MadridMadrid28049Spain

The^(10)boron neutron-capture therapy(BNCT)is an emerging antitumoral method that shows increasing biomedical interest.BNCT is based on the selective accumulation of the^(10)boron isotope within the tumor,which is then irradiated with low-energy thermal neutrons,generating nuclear fission that produces 7lithium,4helium,andγrays.Simple catechol-borate esters have been rather overlooked as precursors of melanin biosynthesis,and therefore,a proof-of-concept approach for using dopamine-borate(DABO)as a suitable boron-containing candidate for potential BNCT is presented here.DABO can spontaneously oxidize and autopolymerize in vitro,giving a soluble,eumelaninlike brown-black poly-DABO product.Melanotic melanoma cell cultures treated with 1 mM DABO for 24 and 48 h were viable and showed no signs of damage or cell death.The stability and possible trans-esterification of DABO is shortly discussed.Chemical calculations and quantitative structure-activity relationships(QSAR)analysis of DABO and the BNCT agent BPA indicated that they should be cell permeant and accumulate within lysosomes and melanosomes.Molecular modeling allows visualization of both the DABO precursor and the structure of a borate derivative of the proposed catechol-porphycene model for eumelanin,showing interesting features from molecular orbital calculations.The main difference between DABO and other agents,such as BPA,is that it is not a boronic acid nor a boron cluster.This simple catechol-borate ester(protected from oxidation and blackening)could be administrated to living cells and organisms,in which biosynthesis of boron-melanin in melanoma melanocytes can lead to improved BNCT.

关键词： ^(10)Boron Borate esters Catechols Dopamine eumelanin Melanoma

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical overview of melanin.2.Updating molecular modeling,synthesis mechanism,and supramolecular properties regarding melanoma therapy

引用

BIOCELL 2022年第6期46卷 1391-1415页

作者： JUAN CARLOS STOCKERT ALFONSO BLÁZQUEZ-CASTRO Facultad de Medicina Instituto de Oncología“Angel H.Roffo”Universidad de Buenos AiresBuenos AiresC1417DTBArgentina Centro Integrativo de Biología y Química Aplicada(CIBQA) Universidad Bernardo O’HigginsSantiago8370854Chile Departamento de Biología Facultad de CienciasUniversidad Autónoma de MadridMadrid28049Spain

Melanins represent one of the most ancient and important group of natural macromolecular pigments.They have multiple biological roles in almost all organisms across the Phyla,examples being photoprotection,anti-oxidative action,radical scavenger activity,and heavy metal removal.From the biomedical point of view,melanocytes are involved in the origin of melanoma tumors,and the main therapeutic advances for their treatment have been revised in Part 1 of this review.The chemical structure of eumelanin is a biological concern of great importance,and therefore,exploring theoretical molecular models and synthesis mechanisms will be here described,as well as molecular orbital features and supramolecular organization,which are responsible for the key properties that make these biological pigments so important,and so fascinating.Ultimately,this updated overview is devoted to describe present structural models and physico-chemical characteristics of eumelanin,in order to explain and utilize melanin properties on which new photothermal and ultrasonic protocols for melanoma treatment can be devised and applied.

关键词： eumelanin Melanin models Melanin synthesis Molecular orbitals Supramolecular structure

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Increased dietary intake of tyrosine upregulates melanin deposition in the hair of adult black-coated dogs

引用

Animal Nutrition 2018年第4期4卷 422-428页

作者： Adrian Watson Jamie Wayman Russell Kelley AlexANDre Feugier Vincent Biourge Royal Canin Research Centre 30470 AimarguesFrance Royal Canin Pet Health Nutrition Center LewisburgOH 45338USA

The principle determinant of melanin derived hair colour and patterning in mammals is genetic, but environmental factors are now thought to play a role. It has been shown that the concentration of melanins in cat hair is influenced by the amino acid composition of their diets. Also, puppies were found to require tyrosine(Tyr) intake significantly greater than that recommended for normal growth and development in order to optimize melanin expression in their coats. Much of the work to date has been conducted in growing animals. Less is known about the relationship between nutrition and hair melanin deposition in healthy adult animals. In this study, we fed 2 groups of adult black Labrador retrievers(12 dogs/group) different concentrations of Phe + Tyr(5.6 vs. 3.5 g/Mcal) for 24 weeks and used spectrophotometric measurements every 8 weeks to detect any associated changes in the dogs' hair colour.The higher intake dogs showed reduced dilution of their black coat pigment compared with the lower intake dogs. Specifically, following 16 weeks at the higher intake, the dogs showed less yellow pigmentation to their coats(P = 0.0032), and after 24 weeks at the higher intake, the dogs showed less red(P < 0.0001) and yellow(P< 0.0001), as well as greater overall dark pigmentation(P < 0.0001). In conclusion, we have demonstrated for the first time that colour expression in the hair-coat of adult dogs is dependent on dietary intake of Tyr, and that the requirement appears to be in excess of the minimum level recommended to maintain health.

关键词： Canine Phenylalanine Amino acids Hair colour eumelanin Pheomelanin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Isolation and Characterization of Melanin Pigment from Yesso Scallop Patinopecten yessoensis

引用

Journal of Ocean University of China 2017年第2期16卷 279-284页

作者： SUN Xiujun WU Biao ZHOU Liqing LIU Zhihong DONG Yinghui YANG Aiguo Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences College of Biological and Environmental Sciences Zhejiang Wanli University

Melanin is one of the essential compounds in the pigments of molluscan shells.However,the effects of melanin on color variations in molluscs are largely unknown.Our previous study suggests that Yesso scallop Patinopecten yessoensis might contain melanin pigment in the dark brown shell.We therefore isolated melanin from the pigmented shells using hydrochloric acid method,and characterized the types of melanin pigments by spectrophotometry.The purified melanin,which was verified by spectrophotometry scanning and HPLC analysis,showed the typical characteristics of melanin absorption spectra and HPLC chromatograms.The contents of pheomelanin and eumelanin in pigmented shells,which were determined by the linear standard curve of melanin at 405 nm and 350 nm absorbance,were 48.23 ? 1.350 and 157.65 ? 5.905 mg,respectively.The present results indicate that the brown-pigmented shells of scallops comprise approximately 76.6% of eumelanin and 23.4% of pheomelanin,which supports the presence of eumelanin-rich pigment in scallop shells.Therefore,the combination of hydrochloric acid extraction and spectrophotometric quantification is a rapid and efficient method to isolate and quantify melanin in shells.This will facilitate the melanin studies related to shell color polymorphism and the selective breeding of bivalves with different shell colors.

关键词： eumelanin pheomelanin hydrochloric acid method spectrophotometry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：