脂溶性橘皮黄色素的提取工艺分析

"绿色主题"号召越来越强的当今,天然色素因具有染色效果佳、可靠性高、色泽自然纯正等特点,受到人们的青睐,关于天然色素的研究亦越发火热;本实验以橘皮为实验对象,采用乙醇浸提获得色素粗品,石油醚萃取纯化得脂溶性橘皮色素。通过单因素实验和正交试验优化提取条件,结果表明:因素A(料液比)、因素B(乙醇浓度)、因素C(浸提温度)、因素D(浸提时间)4个单因素的影响顺序为A(料液比g/m L)D(浸提时间h)C(浸提温度℃)B(乙醇浓度%);确定橘皮色素提取的最佳工艺为A2B1C1D2,即:料液比1:10、浸提24 h、浸提温度50℃、乙醇浓度85%。通过对此提取工艺的研究,为更好的开发利用橘皮提供了一定的科学的理论依据。     

葡萄皮色素提取条件的综合研究

利用葡萄饮料厂生产加工的废料葡萄皮提取天然色素,并对影响色素提取率的因素如:提取溶剂的选择、提取剂用量、提取温度、提取时间及提取pH等条件进行研究,初步确定获得最大提取收率的条件,即:以无水乙醇为提取剂,葡萄皮重(g)与提取剂的用量(mL)之比为1 7,提取温度60~80℃,时间为70min,pH为2~4。同时对提取次数进行了研究,结果表明提取2次较好。     

桑椹红色素纯化的动态吸附条件研究

桑椹红色素是一种安伞、无毒的食用天然色素。本实验埘8种大孔吸附树脂进行筛选,然后通过单因素试验、正交试验和方差分析确定了吸附桑椹红色素的最佳操作条件。结果表明,LSA-21树脂对桑椹红色素的吸附和解吸性能较好;确定的最佳吸附条件为：料液浓度(以吸光度计)为0．425Abs,上柱速度3．5BV／h,料液pH1．57。     

黑果枸杞色素的提取和精制工艺研究

本文采用正交实验法对黑果枸杞色素的提取和精制工艺进行了研究。结果表明,黑果枸杞色素的最佳提取条件为:以pH 3.0的80%乙醇作浸提剂,提取温度50℃,提取时间3 h,固液配比1:40;用X-5大孔吸附树脂对色素进行精制,以树脂柱径高比1:15、流速3 mL/minp、H 3.0、色素液浓度1 g/L为最佳吸附条件,色素的吸附量可达0.03715 g/mL湿树脂体积;而以95%乙醇做洗脱液,在pH 2.0、流速5 mL/min、3倍于柱床体积的洗脱液条件下解吸附效果最佳,色素回收率达到97.78%;制取的色素产品外观呈紫红色,色价为36.7。     

产黑色素海洋放线菌的分离、鉴定和产色素条件优化

【目的】从连云港高公岛沿岸海底泥样中分离筛选到一株产黑色素的海洋放线菌。【方法】对筛选得到的菌株HT-18所产的色素进行紫外-可见吸收光谱、红外光谱分析。通过形态特征、培养特征、生理生化测定以及16S rRNA序列的系统发育学分析确定菌株HT-18的分类学地位。采用单因素对产色素发酵条件进行优化。【结果】菌株HT-18所产色素为黑色素。鉴定该菌株属链霉菌属(Streptomyces)。最佳产色素条件为:初始pH7.0,装液量为70/250 mL,温度31°C,发酵时间为3 d。【结论】海洋链霉菌HT-18是一株具有研究和应用潜力的产黑色素菌株。     

红酵母RY-4中虾青素的分离纯化研究

本文主要研究了红酵母RY-4菌株中天然虾青素的提取和纯化工艺。通过各种破壁提取方法的比较分析,得出了酸热法破壁丙酮提取为较经济理想的粗色素提取方法,提取的粗色素油中虾青素含量达51.7%。通过对各种柱层析条件的摸索研究,得出了以硅胶为吸附剂,Ⅴ(石油醚)∶Ⅴ(乙酸乙酯)混和液为洗脱剂梯度洗脱从粗色素油中分离纯化虾青素的方法,所得虾青素纯度达到97%。     

紫甘蓝色素的提取及组分的研究

从紫甘蓝中提取色素并研究色素的主要成分。通过正交实验确定了紫甘蓝色素的最佳提取条件:60%的乙醇溶液、料液比1∶50、pH=1、提取时间60min;经AB-8大孔吸附树脂纯化后,采用液相色谱-质谱法(LC-MS)对紫甘蓝色素的组分进行了分析,结果表明紫甘蓝色素主要有七种组分,是矢车菊花青素的一系列糖苷及其酰化物。     

仙人掌红色素的研究

仙人掌红色素是从仙人掌科(Gactaceae)仙人掌属植物(Opuntia dillenii (Ker-Gawl.) Hawl)的成熟果实中提取的一种天然食用色素。在pH2—8范围内呈鲜艳的紫红色。色素的主要化学成份是甜菜花青素(betacyanines):甜菜甙(betanin)。本色素为水溶性色素,对光、热不稳定,抗坏血酸能提高色素的热稳定性。     

天然食用密蒙花黄色素的研究

密蒙花黄色素是从醉鱼草科(Buddlejaceae)醉鱼草属(Buddleja Linn.)植物密蒙花树(Budd Leja officinaLis Maxim.)的花蕾中提取的一种天然食用色素。色素的主要化学成份是藏花素(Crocin)。该色素是水溶性色素,对热稳定,在pH 6—7范围内光稳定性好;氧化剂、还原剂、盐、糖、淀粉、金属离子(除Fe离子外)对色素的色译、色价无不良影响。     

天然色素加工新进展及发展对策研究

综述了天然色素加工最新进展,提出天然色素加工存在着加工工艺落后、加工设备简单、加工过程不规范等问题,并从天然色素加工理念、加工工艺、加工设备和开发新型天然色素等方面探讨了提升我国天然色素加工水平的对策。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).