生命的色素、光的信使、光能转换器-叶绿素

　

---叶绿素把光能转化为氧气、血红素把氧气输送到组织细胞---

　

　

上图：叶绿素提取物在白光下呈绿色 下图：叶绿素提取物在紫外光下发出红色荧光

　

叶绿素荧光在从激发态到非激发态返回期间由叶绿素分子重新发射。它被用作高等植物，藻类和细菌中光合能量转换的指标。激发的叶绿素通过驱动光合作用（光化学能量转换），非光化学猝灭中的热量或作为荧光辐射的发射来消散吸收的光能。由于这些过程是互补过程，叶绿素荧光分析是植物研究中的一个重要工具，具有广泛的应用范围。[1]

Chlorophyll fluorescence is light re-emitted by chlorophyll molecules during return from excited to non-excited states. It is used as an indicator of photosynthetic energy conversion in higher plants, algae and bacteria. Excited chlorophyll dissipates the absorbed light energy by driving photosynthesis (photochemical energy conversion), as heat in non-photochemical quenching or by emission as fluorescence radiation. As these processes are complementary processes, the analysis of chlorophyll fluorescence is an important tool in plant research with a wide spectra of applications.[1]

　

　

　

当叶绿素降解时，最初的步骤是从分子中心丢失镁或者叶绿素尾部的损失。前一种途径导致分子形成，即脱镁叶绿素（phaeophytin）;在后一途径中，所得分子称为脱植基叶绿素（chlorophyllide)。降解方案如图2所示。褐藻素或叶绿素的进一步降解产生称为phaeophorbide的分子：褐藻素被叶绿素尾部的损失降解，叶绿素失去其镁离子。当叶绿素分子分解时，根据母体分子，将产生许多不同的phaeophytins，叶绿素和phaeophorbides。其中一些细分产品。

　

As a chlorophyll degrades, the initial step is either the loss of the magnesium from the center of the molecule or the loss of the phytol tail. The former pathway results in the formation of the molecule, phaeophytin; in the latter pathway, the resulting molecule is termed a chlorophyllide. The degradation scheme is shown in Figure 2. Further degradation of either the phaeophytin or the chlorophyllide produces a molecule termed a phaeophorbide: phaeophytin is degraded by the loss of the phytol tail and a chlorophyllide loses its magnesium ion. When a chlorophyll molecule breaks down, a number of distinct phaeophytins, chlorophyllides, and phaeophorbides will be produced, depending on the parent molecule. Some of these breakdown products.

　

　

卟啉，任何一种水溶性含氮生物色素（生物色素），其衍生物包括血红素蛋白（卟啉与金属和蛋白质结合）。血红素蛋白的实例是高等植物的绿色光合叶绿素;许多动物血液中的血红蛋白;细胞色素，在大多数细胞中以微量存在的酶，参与氧化过程;和过氧化氢酶，也是一种广泛分布的酶，可加速过氧化氢的分解。

Porphyrin, any of a class of water-soluble, nitrogenous biological pigments (biochromes), derivatives of which include the hemoproteins (porphyrins combined with metals and protein). Examples of hemoproteins are the green, photosynthetic chlorophylls of higher plants; the hemoglobins in the blood of many animals; the cytochromes, enzymes that occur in minute quantities in most cells and are involved in oxidative processes; and catalase, also a widely distributed enzyme that accelerates the breakdown of hydrogen peroxide.

　

该卟啉类分子的共同特征是与电磁辐射的相互作用，其在可见区域中产生有趣的吸收和荧光现象。

A common feature of this porphyrin class of molecules is the interaction with electromagnetic radiation which gives rise to interesting phenomena of absorption and fluorescence in the visible region.

　

　

吡咯，杂环系列的任何一类有机化合物，其特征在于由四个碳原子和一个氮原子组成的环结构。吡咯族中最简单的成员是吡咯本身，一种分子式为C4H5N的化合物。吡咯环系统存在于氨基酸脯氨酸和羟脯氨酸中;以及有色天然产物，如叶绿素，血红素（血红蛋白的一部分）和胆色素。吡咯类化合物也存在于生物碱中，生物碱是植物产生的一大类碱性有机氮化合物。在血红素和叶绿素中，四个吡咯环连接在一个更大的环系统中，称为卟啉。胆色素是通过卟啉环的分解形成的，并含有四个吡咯环链。

Pyrrole, any of a class of organic compounds of the heterocyclic series characterized by a ring structure composed of four carbon atoms and one nitrogen atom. The simplest member of the pyrrole family is pyrrole itself, a compound with molecular formula C4H5N. The pyrrole ring system is present in the amino acids proline and hydroxyproline; and in coloured natural products, such as chlorophyll, heme (a part of hemoglobin), and the bile pigments. Pyrrole compounds also are found among the alkaloids, a large class of alkaline organic nitrogen compounds produced by plants. In heme and chlorophyll, four pyrrole rings are joined in a larger ring system known as porphyrin. The bile pigments are formed by decomposition of the porphyrin ring and contain a chain of four pyrrole rings.

　

　

　

叶绿素a代谢物，包括植物卟啉（phytoporphyrin, phylloerythrin）的感光性牲畜血液中的光动力学：概述和测量

　

Photodynamic chlorophyll a metabolites, including phytoporphyrin (phylloerythrin), in the blood of photosensitive livestock: Overview and measurement

　

　

抽象

目的：验证用于测量叶绿素a代谢物的荧光分光光度法，特别是光敏牛和羊的血液中的 植物卟啉，chlorin, 脱镁叶绿酸a和焦脱镁叶绿素a。

 

方法：制备脱镁叶绿酸a（25μM），焦脱镁叶绿酸a（25μM）和植物卟啉（<3.7μM）的标准甲醇溶液。血液和血浆样本来自牛（n = 5），绵羊（n = 3）和一只羊驼，临床面部湿疹（即光敏），以及临床正常（每组n = 2）成年奶牛，最近断奶的小牛和羊（对照）。使用高效液相色谱（HPLC），质谱法，结合吸收和发射光谱数据表征三种代谢物的标准溶液，并与来自光敏动物的血清进行比较。在后者中，植物卟啉(phytoporphyrin)是检测到的唯一代谢物。通过将不同比例的甲醇和甲基卟啉的标准溶液加入来自对照动物的稀释血清中来制备校准曲线。在来自光敏动物的样品中测定荧光光谱的峰面积。

 

结果：Pheophorbide a和pyropheophorbide a产生典型的二氢卟酚光谱，激发/发射最大值分别为408/669 nm和409/669 nm。 Phytoporphyrin显示典型的卟啉荧光光谱，激发/发射最大值为425/644 nm。 Pyropheophorbide a和phytoporphyrin具有非常相似的色谱保留时间，相同的化学式和相同的质量，但可以通过它们的吸收光谱的差异来区分。在来自光敏动物的血清中，显示644nm处的荧光发射仅来自植物卟啉(photoporphyrin)，而不是来自任何其他叶绿素a代谢物。使用来自对照动物的血清和血浆的校准曲线给出了0.4-6μM范围内的植物卟啉的可靠测量。受面部湿疹影响的牛和羊的血清的植物卟啉浓度分别为0.4至1.8和0.9至2.8μM。用该方法，溶血的血清样品不适合用于测定植物卟啉。

 

结论和临床相关性：用于量化光敏动物血液中卟啉的荧光分光光度法已得到验证，可用于测量血液中其他叶绿素a代谢物。这将是进一步研究农场动物特发性光敏性的原因和发病机制的有用工具。

 

关键词：叶绿素，色谱法，面部湿疹，脱镁叶绿酸，光敏性，绿藻红蛋白，植物卟啉，焦脱镁叶绿酸，分光光度法

　

　

Photodynamic chlorophyll a metabolites, including phytoporphyrin (phylloerythrin), in the blood of photosensitive livestock: Overview and measurement

 

Abstract

AIM: To validate a spectrofluorometric method for measuring chlorophyll a metabolites, specifically phytoporphyrin (= phylloerythrin), as well as the chlorins, pheophorbide a and pyropheophorbide a, in the blood of photosensitive cattle and sheep.

 

METHODS: Standard methanolic solutions of pheophorbide a (25 µM), pyropheophorbide a (25 µM), and phytoporphyrin (<3.7 µM) were prepared. Serum and plasma samples were obtained from cattle (n=5), sheep (n=3), and one alpaca, with clinical facial eczema (i.e. photosensitive), as well as from clinically normal (n=2 of each) adult cows, recently weaned calves, and sheep (controls). Standard solutions of the three metabolites were characterised using high-performance liquid chromatography (HPLC), with mass spectrometry, in conjunction with absorption and emission spectral data, and were compared with sera from photosensitive animals. In the latter, phytoporphyrin was the only metabolite detected. Calibration curves were prepared by adding different ratios of methanol and standard solutions of phytoporphyrin in methanol to diluted serum from control animals. Peak areas of fluorescence spectra were determined in samples from photosensitive animals.

 

RESULTS: Pheophorbide a and pyropheophorbide a produced typical chlorin spectra, and had excitation/emission maxima of 408/669 nm and 409/669 nm, respectively. Phytoporphyrin showed a typical porphyrin fluorescence spectrum, with excitation/emission maxima of 425/644 nm. Pyropheophorbide a and phytoporphyrin had very similar chromatographic retention times, the same chemical formula and same mass, but were distinguishable by differences in their absorption spectra. In sera from photosensitive animals, the fluorescence emission at 644 nm was shown to arise solely from phytoporphyrin and not from any other chlorophyll a metabolites. Calibration curves using sera and plasma from control animals gave reliable measurements of phytoporphyrin in the range 0.4–6 µM. The sera of facial eczema-affected cattle and sheep had concentrations of phytoporphyrin ranging from 0.4 to 1.8 and 0.9 to 2.8 µM, respectively. Haemolysed serum samples were not suitable for determination of phytoporphyrin with this method.

 

CONCLUSIONS AND CLINICAL RELEVANCE: A spectrofluorometric method for the quantification of phytoporphyrin in the blood of photosensitive animals has been validated, and can be applied to the measurement of other chlorophyll a metabolites in blood. This will be a useful tool in the further investigation of the cause and pathogenesis of idiopathic photosensitivities of farm animals.

 

KEY WORDS: Chlorophyll, chromatography, facial eczema, pheophorbide, photosensitivity, phylloerythrin, phytoporphyrin, pyropheophorbide, spectrophotometry

 

Photodynamic chlorophyll a metabolites, including phytoporphyrin (phylloerythrin), in the blood of photosensitive livestock: Overview and measurement: New Zealand Veterinary Journal: Vol 58, No 3  https://www.tandfonline.com/doi/abs/10.1080/00480169.2010.67517?src=recsys&

　

　

动物中的光敏性疾病 Photosensitization in Horse

　

罗宾逊目前的马医学治疗（第七版），2015 光敏化是皮炎的罕见原因，但在马中可能是严重的问题。与光敏化相关的疾病谱范围从与牧草植物接触相关的简单麻烦到危及生命的肝源性危机。临床症状通常在暴露于强烈阳光后几小时开始，包括红斑，水肿，渗出，结痂形成和皮肤坏死。当皮肤被光动力剂敏化然后暴露于紫外（UV）光时发生光敏化。光敏化不同于晒伤或光照性皮炎，两者都独立于光动力剂发展。兽医在早期阶段识别和治疗光敏化的能力将为他们的马患者提供所有病例的最佳舒适度，并在肝源性病例中提高生存率。

　

Photosensitization Ann Rashmir-Raven, Rebecca S. McConnico, in Robinson's Current Therapy in Equine Medicine (Seventh Edition), 2015 Photosensitization is an uncommon cause of dermatitis but a potentially serious problem in horses. The spectrum of disease associated with photosensitization ranges from being a simple nuisance associated with pasture plant contact to a life-threatening crisis of hepatogenous origin. Clinical signs typically begin a few hours after exposure to intense sunlight and include erythema, edema, exudation, scab formation, and skin necrosis. Photosensitization occurs when skin is sensitized by a photodynamic agent and then is exposed to ultraviolet (UV) light. Photosensitization differs from sunburn or photodermatitis, both of which develop independently of a photodynamic agent. Veterinarians' ability to recognize and treat photosensitization in the early stages will provide their equine patients optimal comfort in all cases and enhanced survival in cases of hepatogenous origin. 光敏 Ann Rashmir-Raven，Rebecca S. McConnico，

　

　

光敏

当光动力物质进入皮肤并通过足够的紫外线作用以激活炎症或产生释放能量的光化学反应，导致随后的皮肤损伤时，发生光敏化（方框7-1）。特定波长的紫外线的吸收和足以激活光动力物质的持续时间主要发生在皮肤的浅色或非色素沉着区域，并且在皮肤既未着色且毛发少的情况下尤其明显。粘膜皮肤交界区和白发斑是牛最常见的光敏感部位。

Photosensitization

Photosensitization occurs when a photodynamic substance enters the skin and is acted on by sufficient ultraviolet light to activate inflammation or create a photochemical reaction that releases energy, causing subsequent skin damage (Box 7-1). The absorption of ultraviolet light of specific wavelengths and sufficient duration to activate photodynamic substances primarily occurs in light or nonpigmented regions of skin and is especially noticeable where the skin is both nonpigmented and has few hairs. Areas of mucocutaneous junctions and patches of white hair are the most common sites of photosensitization in cattle.

　

　

　

反刍动物（绵羊，山羊和牛）的生物学和疾病

Biology and Diseases of Ruminants (Sheep, Goats, and Cattle)

　

Wendy J. Underwood DVM，MS，DACVIM，...... Adam Schoell DVM，DACLAM，实验动物医学（第三版），2015

e光敏化（Bighead）

光敏化是与光敏化学品和阳光之间的相互作用相关的急性皮炎。通常摄取光敏化学品，但在某些情况下，可通过接触进行暴露。缺乏色素的动物更容易患这种疾病。发生三种类型的光敏化：原发性，继发性或肝细胞性和异常性。初级光敏化与植物色素或药物如吩噻嗪，磺胺或四环素有关。二次光敏化在大型动物中更常见，并且特别与植物色素绿藻红素有关。 植物卟啉（phytoporphyrin or Phylloerythrin）是一种卟啉化合物，是瘤胃微生物消化释放的叶绿素的降解产物。通过胆管系统阻止绿藻红素的正常结合和排泄的肝脏疾病或损伤易于光敏化。异常光敏化的唯一例子是牛的先天性卟啉症（参见第III节，B，1）。

　

病理学上，光敏化学物质沉积在皮肤中并被吸收的阳光激活。活化的色素将局部氨基酸和蛋白质转化为血管活性物质，这增加了毛细血管的渗透性，导致液体和血浆蛋白质损失并最终导致局部组织坏死。光敏化可在阳光照射后数小时至数天内发生，并产生面部，外阴和冠状带的损伤。病变最容易发生在白发或稀疏的头发区域。最初，发生嘴唇，角膜，眼睑，鼻平面，面部，外阴或冠状带的水肿。面部水肿，鼻孔收缩和嘴唇肿胀可能导致呼吸困难。对于二次光敏化，黄疸也很常见。可能发生坏死和坏疽。诊断基于临床病变和暴露于光敏化学品和阳光。治疗是有症状的。

　

 

SPPs= secondary products produced by higher plants

　

Biology and Diseases of Ruminants (Sheep, Goats, and Cattle)

　

Wendy J. Underwood DVM, MS, DACVIM, ... Adam Schoell DVM, DACLAM, in Laboratory Animal Medicine (Third Edition), 2015

e Photosensitization (Bighead)

Photosensitization is an acute dermatitis associated with an interaction between photosensitive chemicals and sunlight. Photosensitive chemicals are usually ingested but in some cases exposure may be by contact. Animals with a lack of pigment are more susceptible to the disease. Three types of photosensitization occur: primary, secondary or hepatogenous, and aberrant. Primary photosensitization is related to plant pigments or drugs such as phenothiazine, sulfonamides, or tetracyclines. Secondary photosensitization is more common in large animals, and is specifically related to the plant pigment phylloerythrin. Phylloerythrin, a porphyrin compound, is a degradation product of chlorophyll released by rumen microbial digestion. Liver disease or injury, which prevents normal conjugation of phylloerythrin and excretion through the biliary system, predisposes to photosensitization. The only example of aberrant photosensitization is congenital porphyria of cattle (see Section III, B, 1).

Pathologically, the photosensitive chemical is deposited in the skin and is activated by absorbed sunlight. The activated pigments convert local amino acids and proteins to vasoactive substances which increase the permeability of capillaries leading to fluid and plasma protein losses and eventually local tissue necrosis. Photosensitization can occur within hours to days after sun exposure and produces lesions of the face, vulva, and coronary bands. Lesions are most likely to occur on white-haired or thinly haired areas. Initially, edema of the lips, corneas, eyelids, nasal planum, face, vulva, or coronary bands occurs. Facial edema, nostril constriction, and swollen lips potentially lead to difficulty breathing. With secondary photosensitization, icterus is also common. Necrosis and gangrene may occur. Diagnosis is based on clinical lesions and exposure to the photosensitive chemicals and sunlight. Treatment is symptomatic.

　

　

　

Photosensitizer - an overview | ScienceDirect Topics  https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/photosensitizer

　

IJMS | Free Full-Text | Secondary Plant Products Causing Photosensitization in Grazing Herbivores: Their Structure, Activity and Regulation | HTML  https://www.mdpi.com/1422-0067/15/1/1441/htm

　

Yonsei Med J. 1989 Sep;30(3):212-8. Chlorophyll derivatives--a new photosensitizer for photodynamic therapy of cancer in mice. Park YJ, Lee WY, Hahn BS, Han MJ, Yang WI, Kim BS. Abstract The in vivo photosensitizing efficacy of chlorophyll derivatives (CpD), which had been developed as a new photosensitizer, was compared with that of hematoporphyrin derivatives (HpD). A murine tumor model implanted subcutaneously with S-180 cells on the abdomen was used. The CpD or HpD was administered by intratumoral injection, and light of appropriate wavelength was irradiated on the tumor areas for 10 minutes at 1h and 24h or 24h and 48h after the injection of photosensitizer. When CpD was injected, the early irradiation group (1h and 24h) showed a 100% tumor cure rate; however, the late irradiation group (24h and 48h) showed a 60% tumor cure rate (p less than 0.01). This showed that the early irradiation with light after injection of CpD was an important factor for obtaining better results. With HpD, there was no difference in tumor cure rate between early (1h and 24h, 80%) and late irradiation (24h and 48h, 80%) groups. Thus, in early irradiation groups, the tumor cure rate using CpD (100%) was superior to that of HpD (80%) (p less than 0.05). However, in late irradiation groups, the tumor cure rate using CpD (60%) was inferior to that of HpD (80%), but this difference was not statistically significant (p greater than 0.1). Pathologic sections of these tumors were made before treatment and 48h and 3 weeks after treatment. These showed geographic necrosis at 48h after treatment and no viable tumor tissue at 3 weeks after treatment. Our results showed that CpD was as effective as HpD as a photosensitizer for in vivo photodynamic therapy.

　

PMID: 2588660 DOI: 10.3349/ymj.1989.30.3.212 Chlorophyll derivatives--a new photosensitizer for photodynamic therapy of cancer in mice. - PubMed - NCBI https://www.ncbi.nlm.nih.gov/pubmed/2588660