Vitamins-维生素课件.ppt

Vitamins维生素主要介绍各种维生素的结构、性质和功能，维生素与辅酶的关系,维生素缺乏症。IntroductionDefinition：Vitamins are organic nutrients that are required in small quantities for a variety of biochemical functions and which,generally,cannot be synthesized by the body and must therefore be supplied by the diet食物.historyThe early history of vitamins can be traced to observations that certain disease could be cured by a supplement of another foodstuff.Eg:the ancient Arab physicians and their successors valued the use of liver to cure night blindness,the North America Indian knew that scurvy(坏血病）could be treated by a tea made from cedar(雪松)leaves.In seventeenth century,it was standard procedure for the British Navy to provide lemon juice for its sailors to prevent scurvy.historyThiamine was discovered in 1912&was thought to be a vital amine compound&thus the term vitamin was inventedVita=vital for lifeMin=amineClassification分类 lipid-soluble vitamin:soluble in non-polar organic solventswater-soluble vitamin:soluble in aqueous solventsEssential Vitamins For Human Being vitamins water-soluble lipid-soluble Vit C Vit B A,D,E,K B1,B2,B6,B12,PP,patothenic acid泛酸，folic acid叶酸,biotin生物素,lipoic acid硫辛酸维生素缺乏病的原因1、进食量不足2、吸收障碍3、需要量增加4、服用某些药物 5、生物体特异缺陷（一）维生素C（抗坏血酸 ascorbic acid）Water solublesour taste(acid)Six-carbon polyhydroxy compoundStrong antioxidant 六碳、多羟基化合物.酸性、强还原性1535 Jacques Cartier and his sailors were cured by Newfoundland Indians by drinking the extract from spruce云杉tree needles.1747,British naval surgeon prescribed lime酸橙 to sailors to prevent scurvy.Thus the slang limey for British sailor.2性质易被氧化（易被氧化（较强 较强的 的抗氧化剂）抗氧化剂）水溶液极不稳定，易被 水溶液极不稳定，易被热 热及 及氧化 氧化破坏 破坏在组织中有两种形式存在：还原型与脱氢型。可以通过氧化还原反应互变，因而都具有生理活性。若脱氢型继续氧化或水解，则其活性丧失。3食物来源(Food Sources of Vitamin C)When dietitians say“vitamin C,”people think“oranges.”Food Sources of Vitamin C-fresh fruit and vegetables新鲜蔬菜、水果新鲜蔬菜、水果But these foods are also rich in vitamin C.羟脯氨酸hydroxyproline 和羟赖氨酸hydroxylysine 为胶原蛋白collagen 所特有，羟脯氨酸是维持胶原蛋白四级结构的关键物质。二者分别是在胶原脯氨酸羟化酶hydroxylase 和胶原赖氨酸羟化酶的作用下由脯氨酸proline 和赖氨酸lysine 羟化而成。Vit C是这两种酶的辅助因子。故缺乏Vit C 可造成胶原蛋白合成障碍。Collagen SynthesisVitamin C deficiency维生素C缺乏症：scurvy 坏血病:Its syptoms included swollen and bleeding gums and loose teeth,brittle脆hair and nails,tiredness,problem in the joints 毛细血管脆性capillary fragility增加；牙龈肿胀、出血；鼻衄、月经过多menorrhagia；骨钙化calcification不正常及伤口愈合缓慢多种 如果肺炎的诊断成立，评价病情的严重程度、肺部炎症的播散和全身炎症反应程度。除此之外患者如有下列危险因素会增加肺炎的严重程度和死亡危险：（一）病史 年龄65 岁；存在基础疾病或相关因素，如慢性阻塞性肺疾病（COPD）、糖尿病、慢性心、肾功能不全、慢性肝病、一年内住过院、疑有误吸、神志异常、脾切除术后状态、长期嗜酒或营养不良。（二）体佂 呼吸频率30 次/分；脉搏120 次/分；血压20X109/L；呼吸空气时动脉血氧分压（PaCO2）50mmHg;血肌酐106umol/L 或血尿素氮7.1mmol/L；血红蛋白90g/L 或血红细胞比容0.30；血浆白蛋白25g/L；感染中毒症或弥散性血管内凝血的证据，如血培养阳性、代谢性酸中毒、凝血酶原时间和部分激活的凝血活酶时间延长、血小板减少；X 线胸片病变累及一个肺叶以上、出现空洞、病灶迅速扩散或出现胸腔积液。重症肺炎目前还没有普遍认同的标准，如果肺炎患者需要呼吸支持(急性呼吸衰竭、气体交换恶化伴高碳酸血症或持续低氧血症)、循环支持(血流动力学障碍、外周低灌注)和需要加强监护和治疗(肺炎引起的感染中毒症或基础疾病所致的其他器官功能障碍)可认为重症肺炎。目前许多国家制定了重症肺炎的诊断标准，虽然有所不同，但均注重肺部病变的范围、器官灌注和氧合状态。我国制定的重症肺炎标精品PPT 课件 浏览免费 下载后可以编辑修改。Vitamin C Deficiency Signs齿龈炎瘀斑 出血Pinpoint Bleeding from Scurvy 2 Hydroxylation 参与体内的羟化作用 胶原的合成：参与胆固醇cholesterol的转化transformation：Cholesterol bile acidHydroxylation 参与芳香族氨基酸aromatic amino acids 代谢：在苯丙氨酸phenylalanine转变为酪氨酸tyrosine，酪氨酸转变为羟苯丙酮酸hydroxyphenylpyruvatate，经羟化、脱羧、移位等步骤转变为尿黑酸homogentisate 时亦需Vit C参与。所以当Vit C缺乏时将导致苯酮尿症，黑尿酸症等。Vit C还参与肝脏生物转化biological transformation过程中的许多羟化反应。促进抗体antibody的生成促进造血作用-使难以吸收的Fe3+还原成易吸收的Fe2+(3)其它生化功能 降低血浆胆固醇 防癌：理论上推测（一）（一）structure&propertiesstructure&properties 化学结构及性质化学结构及性质二、Vitamin B1（硫胺素thiamine）硫胺素 硫胺素:含 含S S、-NH2-NH2性质：性质：白色、耐热，加碱破坏 白色、耐热，加碱破坏（烹调不当易损失）（烹调不当易损失）Active form活性形式：thiamin pyrophosphate 焦磷酸硫氨素（）Thiamin is rapidly converted to TPP in the brain and liver by a specific enzymes,thiamin diphosphotransferase 硫胺素二磷酸转移酶.Food Sources of thiamin 来源：Unrefined cereal grains and meat；seeds,nuts,legums豆类 Recommended Dietary Allowance(RDA):M:1.2mg/d，F:1.1mg/d（三）生化作用：1、Vit B1TPP酮酸脱氢酶系的辅酶糖代谢等。eg:TPP是丙酮酸脱羧酶pyruvate decarboxylase和-酮戊二酸脱羧酶-ketoglutarate decarboxylase的辅酶，参与-酮酸的氧化脱羧。2、TPP is necessary as a cofactor for the reactions of the pentose phosphate pathway 是戊糖磷酸途径中转酮酶的辅助因子3、抑制胆碱酯酶choline esterase Vit B1可抑制胆碱酯酶活性，使神经传导所需的乙酰胆碱acetylcholine不被破坏，保持神经的正常传导功能 DEFICIENCY&USESSevere thiamin deficiency can lead to:Beri-Beri Wernicke-Korsakoff syndrome综合征 臨床上會有神智不清、眼動障礙、眼振及厲害的搖晃等表现q Thiamin is used for treatment of congestive充血性的 heart failure心力衰竭&Alzheimers disease as well as in cancer prevention.q beriberi脚气病,末梢神经炎脚气病，主要表现为神经血管系统的损害。根据其典型症状临床上分为三型：1.湿型脚气病：主要表现为心界扩大、心动过速、呼吸窘迫和下肢水肿。2.干型脚气病：表现为腱反射异常、上行性多发性神经炎、肌肉乏力和疼痛、腓肠肌压痛等。3.混合型脚气病：同时出现神经和心血管系统症状，见于严重缺乏者。Wet Beri-BeriRISK OF THIAMIN DEFICIENCY Low intake&alcoholism酒精中毒 Increased consumption:Malaria疟疾&AIDSExcessive loss:hemodialysis血液透析 and diuretics利尿剂 Anti-thiamin factors:tea&coffee.q Thiaminases found in raw fish,raw shellfish&in silkworms.q（1）结构 含核醇ribitol，异咯嗪环isoalloxazine ring.可逆的氧化还原特性碱性条件 碱性条件+光照，易破坏 光照，易破坏三Vitamin B2(riboflavin核黄素)异咯嗪环核醇Food Sources of riboflavin：Adequate amounts of B2 is present in eggs,milk,meat&cereals.广泛，动植物，动物性食物（肝、肾、心多）真菌类、紫菜、奶类、蛋类 酵母yeastRDA：M:1.4mg/d，F:1.2mg/dActive form：FMN，FAD生化作用：Vit B2FMN、FAD黄素酶类的辅基受氢、脱氢、递氢作用生物氧化.有助于脂肪、糖类、蛋白质转化为能量，是修复和维护身体内部和外部皮肤健康必需的营养物质。与视网膜感光作用有关。FMN FMN：Flavin mononucleotide Flavin mononucleotide黄素单核苷酸 黄素单核苷酸FAD FAD：Flavin adenine dinucleotide Flavin adenine dinucleotide黄素腺嘌呤二核苷酸 黄素腺嘌呤二核苷酸 氧化型的FMN或FAD是黄色的，还原后成无色。FMN或FAD有强烈的黄绿色荧光，还原后荧光消失。缺乏症：Symptoms associated with riboflavin deficiency include,glossitis舌炎,seborrhea脂溢性皮炎,angular stomatitis口角炎,cheilosis唇炎，scrotitis 阴囊炎 and photophobia畏光glossitis四、VitPP/niacin,也称抗癞皮病维生素）（一）化学结构及性质（一）化学结构及性质 11、结构：、结构：吡啶吡啶pyridine pyridine衍生物衍生物derivativederivative：尼克酸（烟酸尼克酸（烟酸,nicotinic acid）尼克酰胺（烟酰胺尼克酰胺（烟酰胺,nicotinamide）2 2、性质：、性质：稳定，一般食物中含量较多稳定，一般食物中含量较多肝脏：色氨酸肝脏：色氨酸tryptophantryptophan 尼克酸，仍不足尼克酸，仍不足尼克酸(烟酸)尼克酰胺(烟酰胺)吡啶-3-羧酸nicotinicacid吡啶-3-酰胺nicotinamideFood Sources of Vit PP 食物来源：qNiacin is available in both animal&plant food and is made in the body from tryptophane色氨酸.豆类、粮食、肝脏、肾、瘦肉、鱼、酵母、蘑菇色氨酸在体内合成烟酸：60mg色氨酸=1mg烟酸生化作用：Vit PPNAD、NADP不需氧脱氢酶辅酶递氢生物氧化缺乏症：癞皮病(pellagra)皮炎dermatitis 腹泻diarrhea 痴呆dementiaPellagraPellagraHartnup disease(由于小肠和肾小管对色氨酸和其他几种氨基酸的转运缺陷引起),malignant carcinoid syndrome恶性类癌综合征&Isoniazid异烟肼 can lead to niacin deficiency.长期单吃玉米会导致niacin deficiency。Niacin is toxic in excess.-liver damage 化学本质及性质：吡哆醇pyridoxol，吡哆醛pyridoxal，吡哆胺pyridoxamine.对光、碱敏感，对热稳定五、Vitamin B6（Pyridoxine 吡哆素）吡哆醛 吡哆醇 吡哆胺Active form:pyridoxal phosphate吡哆醛磷酸;pyridoxamine phosphate吡哆胺磷酸;pyridoxal phosphate is the major form transported in plasma血浆来源：广泛生化作用：Pyridoxine functions as a cofactor in enzymes reactions required for the synthesis合成&catabolism分解代谢of the amino acids氨基酸as well as in glycogenolysis糖原分解.eg:Vit B6吡哆醛磷酸、吡哆胺磷酸氨基转移酶的辅酶、氨基酸脱羧酶的辅酶氨基酸分解代谢 另外，具有终止甾类激素效应的作用。(PLP)(PMP)缺乏症：少见临床上常用B6治疗婴儿惊厥和妊娠呕吐。磷酸吡哆醛是-氨基-酮戊酸(ALA)合成酶的辅酶，而ALA合成酶是血红素合成的限速酶。所以，Vit B6缺乏时有可能造成低血色素细胞性贫血和血清铁增高Isoniazid therapy can induce vit B6 deficiency.化学本质与性质：有机酸，稳定六.泛酸（pantothenic acid，遍多酸）pantoic acid戊酸-alanine-丙氨酸