Evidence for two classes of microbodies in meiocytes of the red algaPalmaria palmata

Summary Microbodies, usually spherical and about 0.2 m in diameter, were found to be associated with prophase nuclei in vegetative cells and meiocytes of the red algaPalmaria palmata. Nucleus-associated microbodies in meiocytes were numerous, but they did not react to the DAB cytochemical test for catalase and peroxidase activity. Microbodies not associated with nuclei in the same cells were intensely DAB-positive. Neither aminotriazole nor potassium cyanide inhibited the DAB reaction.     

On the human consumption of the red seaweed dulse (Palmaria palmata (L.) Weber & Mohr)

The red seaweed dulse (Palmaria palmata) is one of the more popular seaweed species for human consumption in the Western world. With a documented historical use up to present days in Ireland, Brittany (France), Iceland, Maine (USA), and Nova Scotia (Canada), it has remained a snack, a food supplement, and an ingredient in various dishes. The trend towards more healthy and basic foodstuffs, together with an increasing interest among chefs for the seaweed cuisine, has posed the need for more quantitative knowledge about the chemical composition of dulse of relevance for human consumption. Here, we report on data for amino acid composition, fatty acid profile, vitamin K, iodine, kainic acid, inorganic arsenic, as well as for various heavy metals in samples from Denmark, Iceland, and Maine.     

Nutritional value of proteins from edible seaweed Palmaria palmata (dulse)

Palmaria palmata (Dulse) is a red seaweed that may be a potential protein source in the human diet. Its protein content, amino acid composition, and protein digestibility were studied with algae collected every month over a 1-year period. Significant variations in protein content were observed according to the season: The highest protein content (21.9 +/- 3.5%) was found in the winter-spring period and the lowest (11.9 +/- 2.0%) in the summer-early autumn period. Most of the essential amino acids were present throughout the year. After 6-hour in vitro digestion in a cell dialysis using porcine pepsin and porcine pancreatin, the digestibility of proteins from Palmaria palmata crude powder, represented by dialyzed nitrogen, was estimated at 29.52 +/- 1.47%. Relative digestibility was 56%, using casein hydrolysis as 100% reference digestibility. In vitro digestibility of proteins extracted in water was analyzed by sodium dodecylsulfate polyacrylamide gel electrophoresis using either bovine trypsin, bovine chymotrypsin, pronase from Streptomyces griseus, or human intestinal juice. Dulse proteins were hydrolyzed to a limited extent, which confirmed a rather low digestibility. Hydrolysis rate was higher with trypsin and lower with chymotrypsin compared with the two other enzymatic systems, pronase and intestinal juice, respectively. The association of algal powder and protein extract to casein and bovine serum albumin, respectively, produced a significant decrease in the hydrolysis rate of the standard proteins. In conclusion, the digestibility of Palmaria palmata proteins seems to be limited by the algae non-proteic fraction.     

Seasonal photosynthetic performance of the endemic antarctic red algaPalmaria decipiens (Reinsch) Ricker

 A male gametophyte of the endemic Antarctic red macroalga Palmaria decipiens (Reinsch) Ricker was cultivated under fluctuating daylengths, simulating the seasonal changes at the site of collection (King George Island, Antarctica). The plant was maintained at 0±1°C, an irradiance of 25 μmol m^-2 s^-1 and under growth-saturating nutrient conditions. Samples were taken at intervals of 3–6 weeks to measure growth, photosynthesis, dark respiration and pigment content. The growth optimum in spring coincided with a higher photosynthetic activity. Whereas dark respiration was constantly low over the year, there was a rapid increase in maximum photosynthetic rate (P_max) in conditions corresponding to September and October. This was correlated with a change in the initial slope (α) of the photosynthesis versus irradiance (P vs I) curve. Higher activity in photosynthesis mainly resulted from higher Chl a and phycobilin concentrations during Antarctic spring, an indication of an increase in absorption cross-section areas of photosynthetic reaction centres. These changes in physiology are discussed in relation to the seasonal growth “strategy” of the species, which is controlled by seasonal variation in daylength. Received: 27 February 1995/Accepted 3 October 1995     

Bioactive chemical constituents of Caesalpinia bonduc (Fabaceae)

Phytochemical studies on the ethanolic extracts of Caesalpinia bonduc (Fabaceae) yielded two new homoisoflavonoids, caesalpinianone, and 6-O-methylcaesalpinianone along with five known natural products, namely, hematoxylol, stereochenol A, 6′-O-acetylloganic acid, 4′-O-acetylloganic acid, and 2-O-β-d-glucosyloxy-4-methoxybenzenepropanoic acid. Structures of these compounds were elucidated with the aid of extensive NMR spectral studies. All of these compounds exhibited different levels of glutathione S-transferase (GST) inhibitory and antifungal activities.     

Studies on the chemical constituents and anticancer activity of Saxifraga stolonifera (L) Meeb

Saxifraga stolonifera, an evergreen dicotyledon, has been identified as an important resource in Chinese medicine due to its anticancer activity. In the present report, chemical components of S. stolonifera (L) Meeb which is found in Guizhou province were investigated. Ten compounds were isolated from ethanol extracts of S. stolonifera plant and were identified as n-C(31)H(64) (1), (n-C(17)H(35))(2)CO (2), beta-sitosterol (3), n-C(29)H(60) (4), Bergenin (5), Protocatechuic acid (6), Gallic acid (7), Quercitrin 3-O-alpha-l-rhamnoside (8), Quercetin (9), and Quercetin 3-O-beta-d-glucopyranoside (10). Among them, n-C(31)H(64) (1), (n-C(17)H(35))(2)CO (2), beta-sitosterol (3), and n-C(29)H(60) (4) were isolated from this plant for the first time. The anticancer activities of S. stolonifera constituents on human gastric carcinoma cell line BGC-823 were evaluated by MTT assay and microscopic observation, DNA fragmentation, and flow cytometry analysis assay. It was found that quercetin could inhibit cell viability after 72 h of exposure. Furthermore, DNA ladder assay revealed that quercetin could induce DNA strand break in a concentration- and time-dependent fashion. Flow cytometric analysis shows that quercetin can induce 11.82% BGC-823 cell apoptosis in 48 h. These data reveal that quercetin is a potential agent capable of inducing apoptosis in BGC-823 cells.     

Meristem clusters in cortical layer of thallus cells of the cultured red alga Palmaria palmata

For the first time somatic spotlike formations of 1.5 mm in diameter and height up to 0.5 mm were revealed in thalli of the red alga Palmaria palmata reared in an aerated stirred culture. It was determined that some cortical cells of the thallus are able to divide in the periclinal and anticlinal directions forming spots. Deep freezing and subsequent thawing of thalli showed that the cortical cells of spots were meristematic cells. In certain conditions they enabled the formation of prolifications, which germinated plantlets. These clusters of meristem tissue in the cortical layer of cells of the thallus of P. palmata, which were formed in the culture as in nature, function as growth cells facilitating growth of thalli in thick and natural “planting material” formed upon thalli fragmenting after their freezing in the winter season.     

Enzymatic biocatalysis in chemical synthesis of pharmaceuticals (Review)

In this review we summarize the available research on enzymatic biocatalysis in the chemical synthesis of drugs. We focus on oxydoreductsases, particularly ketoreductases, that are widely used in biotechnological processes: alpha- and omega-transaminases, lipases, nitrile hydrolases, and aldolases. The potential for the extended use of novel enzymes produced via bioengineering is discussed.     

加拿大-西北大西洋地区掌形藻的种群遗传结构与动态变化

探讨古气候波动(如更新世末期冰期)对典型生物的时空分布和有效种群大小变动的影响是生物地理学和进化遗传学的重要研究课题.本文利用线粒体cox2-3序列和RAPD两种分子标记,对分布于加拿大-西北大西洋地区8个地点(共138个个体)的掌形藻(Palmaria palmata)进行谱系地理学研究,试图阐明当更新世冰期来临时掌形藻如何衍生出适应性的进化机制,并形成当前的地理分布格局.结果表明,线粒体cox2-3间区序列共检测出11个单倍型,其中1个单倍型(C3)在所有种群中都有分布,并位于星状基因谱系的中心位置,可认为是祖先单倍型.St.Lawrence湾内北部的两个种群多样性最高,与其他地理种群分化最明显,这与基于RAPD数据的STRUCTURE聚类分析结果相一致.根据掌形藻遗传多样性及其单倍型谱系结构特征,推测掌形藻在加拿大-西北大西洋沿岸存在多个冰期避难所.分子多态性分析(AMOVA)显示掌形藻的遗传变异主要来自种群内,而St.Lawrence湾和Fundy湾群组间的遗传变异较小.cox2-3序列的Bayesian skyline plots分析结果反映出掌形藻种群在加拿大-西北大西洋沿岸经历了轻微的种群扩张,时间大概在0.18-0.13百万年前.St.Lawrence湾和Fundy湾群组间的K2P遗传距离为0.2％,相应的分化时间大约在0.36百万年前.由此推测,更新世末期的冰期及间冰期是影响掌形藻种群结构及变动的重要古气候环境因子.     

缘毛紫菀化学成分研究

我们从菊科植物缘毛紫菀的甲醇提取物的氯仿部分中分离得到6个化合物,并运用红外光谱、质谱、核磁共振等方法鉴定了它们的结构。它们分别为：β—谷甾醇,β—胡萝卜甙,芹菜素,18,19—二羟基—5α,10β—新克罗烷—二烯—丁烯羟酸内酯,橙皮甙,18—O-β—D-吡喃葡萄糖—19-羟基-新克罗烷—二烯—丁烯羟酸内酯。     

长叶水麻化学成分的研究

长叶水麻（Debregeasia longifolia(Burm.f.)Wedd.）是荨麻科植物,果可食;根人药,除风湿。本文首次从其枝,叶乙醇提取物的乙酸乙酯萃取部位分离鉴定出5种黄酮甙类化合物,它们分别为：epicat-echin（化合物1）,quercetin 3-O-β-D-galactopyranoside(化合物2）,kaempferol 3-O-β-D-galactopyranoside(化合物3）,quercetin 7-O-β-D-glucopyanosie(化合物4）,apigenin 7-O-β-D-glucopranoside(化合物5）。     

Seasonal changes in the chemical composition of red deer (Cervus elaphus) semen

During reproductive quiescence, apart from a rapid decrease in total protein content, there was a 2–3 fold decrease in the activity of certain enzymes (glutamic-oxaloacetic transaminase (GOT), alkaline phosphatase, acrosin inhibitors) in the seminal plasma of red deer stags. The activity of the enzymes of the spermatozoa, hyaluronidase and acrosin, increased in the seminal plasma, probably due either to ageing of the spermatozoa, accumulated in the epididymis, or to changes in the permeability of cell membranes.These phenomena were accompanied by an increased concentration of albumins originating in blood, and by a noticeable disappearance of globulin fractions. This would point to a change in the permeability of the tissue barriers in the deer stag reproductive system, and to a decreased rate of protein synthesis in particular sections of this system, especially in the epididymis, during reproductive quiescence.     

益母草属化学成分研究进展

对益母草属植物近20年化学成分研究作了综述,主要成分是生物碱、二萜、苷类。     

药用女贞属植物化学成分的研究进展

在约50种女贞属植物中已进行化学成分研究的有15种,从该类植物中提取分析出一百多种化合物,其中大部分是结构新颖的活性化合物。主要有单萜类,三萜类,环烯醚萜类,裂环烯醚萜类,黄酮类,苯乙醇类,挥发油和其它化合物,本文综述了从该属植物中得到的各类化学成分的结构和^13C-NMR谱图数据。     

翻白草的化学成分

翻白草(Potentilla discolor Bunge)又名鸡腿儿、鸡脚草、鸭脚参、天青地白,为蔷薇科(Rosaceae)委陵菜属(Potentiaal L.)植物,其干燥全草均可入药,是常见的中草药之一.     

Effects of improved post-harvest handling on the chemical constituents and quality of carrageenan in red alga,Kappaphycus alvarezii Doty

Red alga Kappaphycus alvarezii Doty is an important commercial species widely cultivated in southeast Asian countries for its polysaccharide, kappa-carrageenan. Common post-harvest handling technique involves sun-drying of harvested seaweed on platforms at the farms. Quantity and quality of carrageenan varies depending on the duration and care taken during the post-harvest handling of the raw seaweed. In this study, dynamics of moisture content, water activity index (aw), carrageenan yield, and carrageenan quality were investigated by subjecting the seaweed to three post-harvest methods: (1) freeze-drying (FD), (2) shade-drying (SD), and (3) direct sun-drying (DSD). Seaweed dried under FD and SD produced high yield (56–58 %), superior gel strength (1,454–1,424 g cm^?2), high viscosity (57–58 cPs), and low syneresis (15–17 %). But, carrageenan extracted from DSD seaweed gave 28 % lower yield, 38 % lower gel strength, 27 % lower viscosity, and 8–9 % higher syneresis. In addition, gelling temperature and melting temperature of the DSD carrageenan were lower by 4 and 9 °C, respectively. Molecular size analyses of carrageenan extracted from seaweed dried under FD and SD contained carrageenan of 700 KDa (80 %) and 200 KDa (4–10 %). However, carrageenan extracted from DSD seaweed contained smaller carrageenan molecules, 460 KDa (55 %), 210 KDa (25 %), and <100 KDa (20 %). Further, scanning electron microscope images illustrated the severe effects of DSD on the morphology of seaweed cells. Therefore, SD technique was found to be the best post-harvest processing technique that gave quality carrageenan in a high quantity. Due to its simplicity and low cost, it is a practical approach to be practiced in southeast Asian countries.     

Effect of extraction condition on protein recovery and phenolic interference in Pacific dulse (Devaleraea mollis)

Pacific dulse (Devaleraea mollis), a type of red macroalgae, is of particular interest in the context of plant-based protein given its high protein content. One challenge in utilizing seaweed-derived protein is the poor protein recovery/yield and high cost that limits wider adaptation. In this study we aimed to evaluate methods for protein extraction from Pacific dulse to achieve a higher protein recovery rate. We evaluated the effect of cellulase treatment, under two extraction approaches, on the protein recovery and phenolic interference in Pacific dulse extracts. Commercial cellulases Viscozyme and Celluclast (2%, v/v) improved crude protein recoveries in both aqueous-alkaline and sequential protein fractionation approaches. The use of Osborne method to sequentially recover water-, saline-, alkaline-, and ethanol-soluble protein fractions resulted in more than a threefold increase in yield even at low-temperature conditions, mainly with the recovery of more protein in both albumin and globulin fractions. Without cellulase treatment, extending extraction time provides no improvement in protein yield but rather favors an increase in phenolic interference. Collectively, these results show that cellulase-aided sequential protein extraction can be used for improved protein recovery from Pacific dulse.