The Role of Astaxanthin as a Nutraceutical in Health and Age-Related Conditions

The current review provides an up-to-date analysis of scientific data on astaxanthin (ASX) sources and experimental studies on its health benefits as a potent antioxidant in the aging process. ASX is a liposoluble carotenoid nutrient and reddish-orange pigment, naturally synthesized by numerous microalgae, yeasts, and bacteria as secondary metabolites. Provides a reddish hue to redfish and shellfish flesh that feed on ASX-producing microorganisms. The microalga Haematococcus pluvialis is the most important source for its industrial bioproduction. Due to its strong antioxidant properties, numerous investigations reported that natural ASX is a more significant antioxidant agent than other antioxidants, such as vitamin C, vitamin E, and β-carotene. Furthermore, several data show that ASX possesses important nutraceutical applications and health benefits, especially in healthy aging processes. However, further studies are needed for a deeper understanding of the potential mechanisms through which ASX could lead to its effective role in the healthy aging process, such as supporting brain health and skin homeostasis. This review highlights the current investigations on the effective role of ASX in oxidative stress, aging mechanisms, skin physiology, and central nervous system functioning, and shows the potential clinical implications related to its consumption.     

Photosensitization of the yeast phaffia rhodozyma at a low temperature for screening carotenoid hyperproducing mutants

Phaffia rhodozyma strain Ant-1 produces more carotenoids, known as antioxidants, but it was more sensitive to light plus toluidine blue O (TBO), a superoxide producer, than wild strain 67-385 at 20°C. Carotenoid hyper-producing mutants (CHMs), Ant-1 and 2A2N, exhibited decreased activity of superoxide dismutase (SOD) compared to 67-385, and this is in part responsible for hypersensitivity of the mutants to photosensitization. Light plus TBO at 2°C allowed carotenoid hyperproducing mutants to produce higher colony-forming units than the wild-type. Photosensitization with limited cell metabolism by a low temperature, provides an idea of selective conditions for carotenoid hyperproducers ofP. rhodozyma.     

一些生物活性分子的合成进展

对一些生物活性分子的合成研究进展，如NADH（nicotinamide adenine dinucleotide hydrogen)模型、类胡萝卡素相关分子、卟啉衍生物的合成研究作 了简要的概述。     

应用红外光谱显微成像技术观测单细胞雨生红球藻虾青素代谢过程

雨生红球藻是一种适于生产虾青素的单细胞绿藻,虽然已有研究报道了藻细胞内类胡萝卜素的合成代谢途径,但是对类胡萝卜素及虾青素的具体形成过程以及它们在显微尺度上的含量和分布变化还缺乏直接的观测数据和证据。本研究运用高空间分辨率的傅里叶变换红外光谱显微成像技术,对不同时期的单一雨生红球藻细胞中的类胡萝卜素的空间分布和含量进行了观测,根据红外光谱成像数据证实了β胡萝卜素为虾青素合成的前体,并且分析和探讨了细胞中的脂质和蛋白质与虾青素合成及积累的关系。     

开平碉楼灰雕和壁画颜料碎片原材料的拉曼光谱分析

本文采用显微激光拉曼光谱分析了开平碉楼灰雕和壁画黄色颜料碎片的原材料组成,通过分析发现:灰雕的主要成分是稻草杆(作为骨架材料),石灰(CaCO3),沙(石英SiO2)以及黄色颜料类胡萝卜素.壁画黄色颜料碎片的成分则是针铁矿(α-FeOOH)和CaSO4.这也说明开平碉楼在选材上,即使是在同一栋楼内,相同颜色的颜料使用的...     

Raman spectroscopic investigations on intermolecular interactions in aggregates and crystalline forms of trans‐astaxanthin

Astaxanthin is a carotenoid naturally found in microbial organisms, microalgae, and many crustaceans. Its consumption has led to beneficial effects such as pigmentation of marine animals, and it favorably addresses several human health issues as a result of its high important antioxidant property. Several companies produce synthetic trans‐astaxanthin for dietary purposes in aquaculture, where it is mainly used for pigmentation. It is known that trans‐astaxanthin manifests itself as a monomer in organic solvents, as aggregates in aqueous solutions of organic solvents, or as crystalline solids. These forms display unique optical and structural properties, which have an impact on biological systems. In this work, we report on detailed Raman investigations, in conjunction with optical absorption spectroscopy, of monomer, aggregates, and crystalline forms of trans‐astaxanthin. The Raman and optical absorption spectroscopic investigations of trans‐astaxanthin aggregates were performed as a function of time, showing the formation of card‐packed aggregates after 2 h, and head‐to‐tail aggregates after 24 h in a 10% acetone–water astaxanthin solution. For the crystalline trans‐astaxanthin, a pointwise Raman mapping evidenced the presence of two distinct crystal structures. The Raman modes of these crystal structures (A and B) were correlated with the intermolecular interactions present in chloroform solvated (AXT‐Cl) and unsolvated (un‐AXT) trans‐astaxanthin single crystals. Both crystal structure A and the card‐packed aggregates have similar intermolecular π stacking interactions as AXT‐Cl. The crystal structure B and the head‐to‐tail aggregates showed linear chain features as in un‐AXT. This work also clearly demonstrates that Raman spectroscopy is a powerful tool to distinguish the crystal structures present in crystalline powder of trans‐astaxanthin. Copyright © 2012 John Wiley & Sons, Ltd.     

Carotenoids from the ripening bacterium Brevibacterium linens impart color to the rind of the French cheese,Fourme de Montbrison (PDO)

Abstract

Rind color of some high-value PDO cheeses is related to the presence of carotenoids, but little is known about the structure of the pigmented compounds and their origin. Our objective was to describe the carotenoids extracted from the rind of a French cheese, Fourme de Montbrison, and to compare them with the pigments produced by a bacterial strain used as an adjunct culture in the cheese ripening process. Eleven carotenoids were detected in the cheese rinds or in the biomass of Brevibacterium linens. Most of the carotenoids from the rinds belonged to the aryl (aromatic) carotenoid family, including hydroxylated and non-hydroxylated isorenieratene. Chlorobactene, a carotenoid rarely found in food products, was also detected. Agelaxanthin A was identified in the cheese rinds as well as in the B. linens biomass. Occurrence of this compound was previously described in only one scientific publication, where it was isolated from the sponge Agela schmidtii.     

Synergistic Action of Membrane-Bound and Water-Soluble Antioxidants in Neuroprotection

Prevention of neurodegeneration during aging, and support of optimal brain function throughout the lifespan, requires protection of membrane structure and function. We review the synergistic action of different classes of dietary micronutrients, as well as further synergistic contributions from exercise and stress reduction, in supporting membrane structure and function. We address membrane-associated inflammation involving reactive oxygen species (ROS) that produce immune regulators from polyunsaturated fatty acids (PUFAs) of membrane phospholipids. The potential of dietary micronutrients to maintain membrane fluidity and prevent chronic inflammation is examined with a focus on synergistically acting membrane-soluble components (zeaxanthin, lutein, vitamin E, and omega-3 PUFAs) and water-soluble components (vitamin C and various phenolics). These different classes of micronutrients apparently operate in a series of intertwined oxidation-reduction cycles to protect membrane function and prevent chronic inflammation. At this time, it appears that combinations of a balanced diet with regular moderate exercise and stress-reduction practices are particularly beneficial. Effective whole-food-based diets include the Mediterranean and the MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay diet, where DASH stands for Dietary Approaches to Stop Hypertension).     

绿色杜氏藻GGR基因生物信息学分析及表达研究

采用Illumina HiSeqTM 2000高通量测序方法获得绿色杜氏藻GGR基因(GenBank序号: KX100480) cDNA全长序列, 研究了甲基茉莉酸(MeJA)对绿色杜氏藻GGR基因表达的影响. 测序结果表明, 绿色杜氏藻GGR基因cDNA全长2356bp, 开放阅读框1539bp, 编码512个氨基酸, 分子量为52.2961kDa, 理论等电点为6.54. 序列分析结果表明, 该蛋白具有保守的ChlP结构域, 为可溶性蛋白, 具有跨膜区域, 无信号肽. TargetP 1.1 Server预测结果表明, 该蛋白可能定位于线粒体. 系统进化树结果表明, 绿色杜氏藻GGR蛋白较其他植物的GGR蛋白亲缘关系较 远. RT-PCR结果表明, 100?mol·L-1 MeJA可显著地提升绿色杜氏藻GGR基因的表达(P<0.01). 同时, 绿色杜氏藻叶绿素和类胡萝卜素含量达到最高, 说明GGR基因与绿色杜氏藻叶绿素和类胡萝卜素的合成存在一定关系