植物内生真菌及其活性代谢产物研究进展

植物内生真菌是一大类未被充分研究过的真菌,其物种及代谢产物均具有生物多样性,现今从植物内生真菌中得到的活性物质种类远比从土壤微生物中得到的多。对植物内生真菌的研究具有重要的生态学意义和经济学意义,在各个领域中应用前景广泛。作者主要综述了植物内生真菌及其活性物质研究的最新进展。     

海绵生物活性物质及海绵细胞离体培养

介绍了来自海绵的生物活性物质种类、分布及其潜在的应用价值。讨论了其作为抗癌、抗病毒、抗细菌等药用的生物活性物质及其相关的海绵种属 ;强调海绵生物活性物质的商业化和临床应用所面临的“供给短缺问题”。作为解决这一问题的途径之一 ,海绵细胞离体培养是最有前景的技术。讨论了海绵细胞离体培养技术的研究现状 ,存在的问题及未来的发展趋势。对我国海域的海绵生物活性物质的研究开发现状进行总结 ,强调海绵研究对开发具有我国自主知识产权的新药、新化合物的必要性及重要性 ,并提出进行研发的可能优先领域     

Initiation of an Aquaculture of Sponges for the Sustainable Production of Bioactive Metabolites in Open Systems: Example, Geodia cydonium

Among Metazoa, sponges (phylum Porifera) are the richest source for different bioactive compounds. The availability of the raw material is, however, restricted. To obtain enough of the bioactive compounds for application in human therapy, sponges have to be cultured in in vitro systems. One technique for the establishment of a long-term cell culture from sponges has recently been elaborated. Here, we present a procedure to cultivate tissue samples from sponges in an open system. The species Geodia cydonium, which produces bioactive compounds, has been selected. Tissue samples of approximately 10 g were attached to the bottoms of cultivation trays. After 2 to 3 days, the tissue samples formed a robust contact with the metal support. Subsequently, sets of trays, called tray batteries, either remained in huge aquaria at the Center for Marine Research or were transferred to the vicinity of a fish and mussel farm. The growth rates of the samples remained unchanged within the first month; however, after 3 and 6 months, they increased to 147% and 189%, respectively. In parallel, extracts were prepared from the tissue samples and tested for cytotoxicity in a mouse lymphoma cell assay system. Extracts from cultured tissue initially had a low inhibitory potency; however, after cultivation for 3 or 6 months, values comparable to those of extracts from sponges taken from the biotope were found. In addition, a molecular marker was applied to document the response (health state) of the tissue and the identity of the material in culture. The CD63 molecule was chosen because the expression of this molecule in mammalian systems changes with the age of the animals. The corresponding complementary DNA was isolated from Geodia cydonium. With this probe, the level of expression in cultured tissue samples decreased immediately after starting cultivation; after a cultivation period of 6 months, however, values were similar to those found in controls. These data show that sponge species that produce bioactive compounds can be cultivated in open systems, in which they retain their potency to produce bioactive compounds as well as their health state. Received September 16, 1998; accepted June 18, 1999     

Bioactive Compounds of Sea Anemones: A Review

Marine organisms and their associated microorganisms contain a wide range of novel bioactive natural compounds that are widely used in the field of anti-microbial, anti-tumor, and anti-cancer drug discovery research. Hence, much focus has been given to isolate the bioactive compounds from marine sources. Sea anemone, one such marine resource, is used in recent years to extract bioactive compounds. It belongs to the phylum Cnidaria. The distinguishing feature of cnidarians is nematocysts, specialized venomous organs that the animals use mainly for capturing prey and protecting themselves from predators. There are over one thousand species of sea anemone reported worldwide and of which 40 species belonging to 17 families are found in India. Out of 40 species, 24 are marine, 13 are estuarine and 3 are common to both habitats. We present an overview of some of the potential marine bioactive compounds from a curative point of view isolated from sea anemone. Among the Order Actiniaria, Family Actiniidae exhibits by far the highest number of species yielding promising compounds, followed by Family Stichodactylidae. Haemolytic activity has been the major area of interest in the screening of actinarian compounds.

     

海洋微生物资源及其产生生物活性代谢产物的研究

海洋微生物,尤其海洋细菌以其分类的多样性和规模而言,作为生物活性物质产生菌的潜力是巨大的。海洋微生物研究依据分离菌的生境来源可分为海水、沉积物、共栖、共生和深海菌群。生境的不同,不但影响菌群的分布,而且影响微生物代谢产物的合成。从报道的研究结果看,沉积物细菌、共栖细菌和共生细菌是海洋微生物天然药物筛选的重要来源。目前海洋微生物生物活性代谢产物资源的研究仍主要限制在那些在“标准”条件下易于生长和培养的微生物类群。本文对海洋微生物资源产生的生物活性物质的研究进展进行了综述。     

A Review on Metabolites from Onchidium Genus: Chemistry and Bioactivity

The Onchidium genus (Mollusca, Gastropoda, Pulmonata, Systellommatophora, Onchidiidae family) is used as the important economical shellfish, due to the high nutritional value and medicinal value. Research over the previous decades indicated that Onchidium sp. mainly contains polypropionates, depsipeptides, terpenoids and other chemical components. Many biological activities of Onchidium (e. g., cytotoxic activities against tumor cells, anti-viral and anti-bacterial activities) have been reported. This review reports a total of 60 compounds, synthetic work and biological studies on Onchidium genus, covering the literature from 1978 to date, with a view to providing a reference and helping for the in-depth research of this genus.     

Venom-Derived Bioactive Compounds as Potential Anticancer Agents: A Review

International Journal of Peptide Research and Therapeutics - Biologically active compounds with potential anticancer activity have been isolated from various animal sources. Recent research is...     

Pulse Derived Bioactive Peptides as Novel Nutraceuticals: A Review

International Journal of Peptide Research and Therapeutics - Bioactive peptides are short peptide fragments formed by amino acids joined by peptide bonds, can employ health enhancing effects in...     

Health Promoting Effects of Food-Derived Bioactive Peptides: A Review

International Journal of Peptide Research and Therapeutics - Bioactive peptides are functional agents encrypted in food proteins with several potential health benefits. Food-derived proteins when...     

A Review on Bioactive Peptides: Physiological Functions,Bioavailability and Safety

International Journal of Peptide Research and Therapeutics - Bioactive peptides can be defined as isolated small fragments of proteins which provide some physiological health benefits. They act as...     

Culture of Explants from the Sponge Mycale cecilia to Obtain Bioactive Mycalazal-Type Metabolites

Natural products with promising biomedical properties have been described from sponges, but the problem of supply is usually a limiting factor for their pharmacological evaluation. Mycale cecilia produces an array of metabolites containing a pyrrole-2-carbaldehyde moiety (e.g., mycalazals and mycalenitriles) that have shown activity as growth inhibitors of the human prostate carcinoma cell line LNcaP. This study shows that the culture of M. cecilia is a viable method to supply mycalazals while protecting the wild population. Small implants were bound to ceramic tiles, and after 3 to 4 days, the tissue samples formed a secure attachment. Subsequently, these explants were simultaneously cultured in their natural environment and in small tanks for 60 days. Sponges in the tanks were fed a diet consisting of a mixture of two microalgae (Tetraselmis sp. and Isochrysis sp.) and powdered yeast Saccharomyces cerevisiae. The final survival of the explants differed significantly between the two farming methods: It was higher in the natural environment (95 ± 7.07%; overall mean ± standard error) than in the enclosed system (65 ± 21.21%). Growth was also higher than in the tanks, and after 60 days, it increased to 207% in the sea and 65% in the tanks, which represented a daily increase of 3.5% and 1.5%, respectively. At the end of the trial, both the explants cultured in the sea and in the tanks retained the production of bioactive metabolites. The mean concentration of pyrrole-2-carbaldehyde derivatives in wild and cultured sponges was determined by ¹H-NMR. These results demonstrate that in-sea aquaculture of M. cecilia is a viable method for supplying the amounts of mycalazal-type compounds needed to advance the studies on their bioactivity.     

红树林放线菌分离鉴定及活性代谢产物研究

以采集自四个红树林地点的16份混合土壤为研究材料,选用7种选择性培养基,共分离获得330株放线菌。其中217株菌经16SrRNA基因序列分析,发现近75%菌株属于小单孢菌属(Micromonospora),其他还包括多形态孢菌属(Polymorphospora),疣孢菌属(Verrucosispora)等小单孢菌科的2个属和非小单孢菌科的9个属。采用美蓝酶标仪法对所分离到的放线菌进行抗菌活性检测,共50株菌表现出对金黄色葡萄球菌(Staphylococcus aureus ATCC 51650)、大肠杆菌(Escherichia coli ATCC 25922)和白色念珠菌(Candida albicans ATCC 10231)有不同程度抗性。然后利用高效液相色谱(HPLC)和液质联用技术(LC-MS)对有生物活性的菌株进行化学筛选,最后确定了5株可能产新颖化合物的小单孢菌。     

Bioactive Secondary Metabolites from Schizogyne sericea (Asteraceae) Endemic to Canary Islands

Schizogyne sericea (Asteraceae) is a halophytic shrub endemic to the Canary Islands and traditionally employed as analgesic, astringent, anti‐inflammatory, and vulnerary. A comprehensive phytochemical investigation was conducted on the flowering aerial parts by analyzing both essential oil constituents and polar compounds. The essential oil was dominated by p‐cymene, with the noteworthy occurrence of β‐pinene and thymol esters. From the EtOH extract, eight compounds were isolated and structurally elucidated. Essential oil, polar fractions, and isolates ( 2 ), ( 4 ), and ( 5 ) were separately in vitro assayed for antiproliferative activity on human tumor cell lines (A375, MDA‐MB 231, and HCT116) by MTT assay, for antioxidant potential by DPPH, ABTS, and FRAP assays, and for antimicrobial activity by the agar disk diffusion method. Results revealed that essential oil and compounds 1 and 2 exert a strong inhibition on tumor cells, and in some cases, higher than that of cisplatin. Fractions containing thymol derivatives ( 1 and 2 ) and caffeoylquinic acid derivatives 4 and 5 displayed antioxidant activity comparable to that of Trolox, making S. sericea extract an interesting natural product with potential applications as preservative or in the treatment of diseases in which oxidative stress plays an important role.     

Isolation and Characterization of Novel Marine-Derived Actinomycete Taxa Rich in Bioactive Metabolites

A unique selective enrichment procedure has resulted in the isolation and identification of two new genera of marine-derived actinobacteria. Approximately 90% of the microorganisms cultured by using the presented method were from the prospective new genera, a result indicative of its high selectivity. In this study, 102 actinomycetes were isolated from subtidal marine sediments collected from the Bismarck Sea and the Solomon Sea off the coast of Papua New Guinea. A combination of physiological parameters, chemotaxonomic characteristics, distinguishing 16S rRNA gene sequences, and phylogenetic analysis based on 16S rRNA genes provided strong evidence for the two new genera (represented by strains of the PNG1 clade and strain UMM518) within the family Micromonosporaceae. Biological activity testing of fermentation products from the new marine-derived actinomycetes revealed that several had activities against multidrug-resistant gram-positive pathogens, malignant cells, and vaccinia virus replication.     

A Review on Bioactive Porcine Peptide,Protegrin-1

International Journal of Peptide Research and Therapeutics - Multi drug resistance is a major problem of the twenty first century. In order to combat this issue, there is an urgent need in the...     

Monilidiols,Characteristic and Bioactive Metabolites of Benomyl-resistant Strains of Monilinia fructicola

A new polygalacturonase was found in a culture filtrate of Aureobasidium pullulans. The enzyme was purified and obtained in crystalline form with 10% recovery. The crystalline enzyme was a homogeneous protein by analyses by sedimentation and electrophoresis. The enzyme was most active around pH 4.5, and stable in the pH range of 4 to 6. Its molecular weight was 42,000 and its isoelectric point was pH 6.0. The enzyme was an endo-polygalacturonase, catalyzing the cleavage of glycosidic bonds of polygalacturonic acid at random.

The enzyme had less protopectinase activity than those of the endo-polygalacturonases that were isolated as protopectin-solubilizing enzymes from Trichosporon penicillatum, Kluyveromyces fragilis, and Galactomyces reessii. Some characteristics were compared with the endo-polygalacturonases, which have potent protopectinase activity.     

Insufficient Milk Supply and Breast Cancer Risk: A Systematic Review

Background

An association between insufficient milk supply, the inability of a mother''s breast milk to provide sufficiently for her infant, and breast cancer has been suggested by observations in animal models. To determine if an association has been reported in epidemiological studies of human breast cancer, a systematic review of the literature has been conducted. We also sought to identify the methodological limitations of existing studies to guide the design of any future prospective studies in this field.

Methodology/Principal Findings

PubMed, EMBASE, Web of Science, BIOSIS, and CAB abstracts were searched. We selected any study that (1) assessed breast cancer in association with breastfeeding history and (2) examined the relationship between insufficient milk supply with breast cancer. Seven relevant studies were identified that met both criteria. There was statistically significant heterogeneity among the results which likely reflects clinically significant differences in definitions of insufficient milk supply and reference groups that were used. Among premenopausal women who had experienced insufficient milk supply, odds ratios (ORs) for breast cancer risk ranged from 0.9 to 16.3. Among postmenopausal women, ORs ranged from 0.6 to 6.7. Based on the range of odds ratios obtained in the studies reported in this review, it remains unclear if there is a true association between insufficient milk supply and breast cancer.

Conclusions/Significance

Although some studies have shown a strong positive association, there is no consistent evidence for an effect of insufficient milk supply on breast cancer risk. Exposure definitions are in need of improvement in order to focus on primary insufficient milk supply. Reference groups consisting of women who have successfully breastfed may also introduce positive bias (inflation of the odds ratio) into study results because of the protective effect of prolonged breastfeeding in the control group.     

中国海洋共附生真菌次生代谢产物最新研究进展

我国海洋共附生真菌研究起步较晚,近年来取得大量有价值的成果,本文主要综述我国海洋共附生真菌次生代谢产物结构和生理活性研究中的最新进展.     

Plant-Derived Bioactive Peptides: A Treatment to Cure Diabetes

International Journal of Peptide Research and Therapeutics - Recent advances in analytical techniques have opened new opportunities for plant-based drug discovery in the field of peptide and...