Characterization of Four Amino Acids Constituting Cyl-2, a Metabolite from Cylindrocladium scoparium

A biologically active metabolite designated Cyl-2 from a phytopathogenic fungus, Cylindrocladium scoparium, was found to be composed of four amino acid residues, which fully account for all of the atoms constituting Cyl-2. These amino acids were identified as L-pipecolic acid, L-isoleucine, D-O-methyltyrosine and 2-amino-8-oxo-9,10-epoxydecanoic acid. Thus, Cyl-2 was established as a cyclotetrapeptide containing novel amino acid residues.     

Isolation and Biological Activity of Cyl-2, a Metabolite of Cylindrocladium scoparium

Three metabolites designated Cyl–1, –2 and –3 were isolated as plant growth regulators from culture filtrate of Cylindrocladium scoparium Morgan, a phytopathogenic fungus. Cy1–2 was obtained as pure crystals, and it revealed marked inhibitory activity on the root growth of lettuce seedlings. Cyl–1 showed inhibition on the same organ, while Cyl–3 showed promotion.     

Low genetic diversity of symbiotic dinoflagellates (Symbiodinium) in scleractinian corals from tropical reefs in southern Hainan Island, China

Endosymbiotic dinoflagellates in the genus Symbiodinium are among the most abundant and important group of photosynthetic protists found in coral reef ecosystems.In order to further characterize this diversity and compare with other regions of the Pacific,samples from 44 species of scleractinian corals representing 20 genera and 9 families,were collected from tropical reefs in southern Hainan Island,China.Denaturing gradient gel electrophoresis fingerprinting of the ribosomal internal transcribed spacer 2 identified 11 genetically distinct Symbiodinium types that have been reported previously.The majority of reef-building coral species (88.6％) harbored only one subcladal type of symbiont,dominated by host-generalist C1 and C3,and was influenced little by the host’s apparent mode of symbiont acquisition.Some species harbored more than one clade of Symbiodinium (clades C,D) concurrently.Although geographically isolated from the rest of the Pacific,the symbiont diversity in southern Hainan Island was relatively low and similar to both the Great Barrier Reef and Hawaii symbiont assemblages (dominated by clade C Symbiodinium).These results indicate that a specialist symbiont is not a prerequisite for existence in remote and isolated areas,but additional work in other geographic regions is necessary to test this idea.     

PCP gene family in Symbiodinium from Hippopus hippopus: low levels of concerted evolution,isoform diversity,and spectral tuning of chromophores

Photosynthetic dinoflagellates have evolved unique water-soluble light harvesting complexes known as peridinin-chlorophyll a-binding proteins (PCPs). Most species of dinoflagellates express either 14 to 17 kDa or 32 to 35 kDa mature PCP apoproteins and do so in stable combinations of isoforms that differ in isoelectric point (pI). The source (posttranslational modification, protein degradation, or genetic) and functional significance of PCP isoform variation have remained unclear. PCPs are encoded by multigene families. However, previous reports conflict over the diversity of PCP genes within gene arrays. We present the first genomic characterization of the PCP gene family from a symbiotic dinoflagellate. Symbiodinium from the Pacific bivalve Hippopus hippopus (203) contains genes for 33 kDa PCP apoproteins that are organized in tandem arrays like those of free-living dinoflagellates Amphidinium carterae, Lingulodinium (Gonyaulax) polyedra, and Heterocapsa pygmaea. The Symbiodinium 203 PCP cassette consists of 1,098-bp coding regions separated by approximately 900-bp spacers. The spacers contain a conserved upstream sequence similar to the promoter in L. polyedra. Surprisingly, sequences of cloned coding regions are not identical, and can differ at up to 2.2% of the nucleotide sites. Sequence variation is found at both silent and nonsilent sites, and analysis of cDNA clones indicate that the variation is present in the mRNA pool. We propose that this variation represents nucleotide diversity among PCP gene copies that are evolving under low-level concerted evolution. Interestingly, the predicted proteins have pIs that are within the range of those published for other species of Symbiodinium. Thus, posttranslational modifications are not necessary to explain the multiple PCP isoforms. We have also identified several polymorphic sites that may influence spectral absorption tuning of chromophores.     

Production and Properties of Lipase from a Newly Isolated Chromobacterium

Out of some 750 strains of microorganisms, a potent bacterium for lipase production was isolated from soil and was identified as Chromobacterium viscosum.

The bacterium accumulates lipase in culture fluid when grown aerobically at 26°C for 3 days in a medium composed of soluble starch, soy bean meal, lard and inorganic salts.

Chromobacterium lipase had an optimum pH of 7.0 for activity at 37°C, and an optimal temperature of 65°C at pH 7.0. The enzyme retained 80% of the activity when heated for 10 min at 70°C. This lipase was capable of hydrolyzing a variety of natural fats and oils, and it was more active on lard and butter than on olive oil. The activity was stimulated by Ca²⁺, Mg²⁺, Mn²⁺ and inhibited by Cu²⁺, Hg²⁺ and Sn²⁺. It was not diminished but rather stimulated by a high concentration of bile-salts.     

A Review of the Chemistry and Biological Activities of Natural Colorants,Dyes, and Pigments: Challenges,and Opportunities for Food,Cosmetics, and Pharmaceutical Application

Natural pigments are important sources for the screening of bioactive lead compounds. This article reviewed the chemistry and therapeutic potentials of over 570 colored molecules from plants, fungi, bacteria, insects, algae, and marine sources. Moreover, related biological activities, advanced extraction, and identification approaches were reviewed. A variety of biological activities, including cytotoxicity against cancer cells, antioxidant, anti-inflammatory, wound healing, anti-microbial, antiviral, and anti-protozoal activities, have been reported for different pigments. Considering their structural backbone, they were classified as naphthoquinones, carotenoids, flavonoids, xanthones, anthocyanins, benzotropolones, alkaloids, terpenoids, isoprenoids, and non-isoprenoids. Alkaloid pigments were mostly isolated from bacteria and marine sources, while flavonoids were mostly found in plants and mushrooms. Colored quinones and xanthones were mostly extracted from plants and fungi, while colored polyketides and terpenoids are often found in marine sources and fungi. Carotenoids are mostly distributed among bacteria, followed by fungi and plants. The pigments isolated from insects have different structures, but among them, carotenoids and quinone/xanthone are the most important. Considering good manufacturing practices, the current permitted natural colorants are: Carotenoids (canthaxanthin, β-carotene, β-apo-8′-carotenal, annatto, astaxanthin) and their sources, lycopene, anthocyanins, betanin, chlorophyllins, spirulina extract, carmine and cochineal extract, henna, riboflavin, pyrogallol, logwood extract, guaiazulene, turmeric, and soy leghemoglobin.     

山东东营凹陷晚更新世海相沟鞭藻类

本文首次描述山东东营凹陷晚更新世海侵层中的沟鞭藻类化石12种含1亚种1比较种和1新种(Dissiliodinium tuberculatum sp．nov．),归属于6属3科;简要介绍了沟鞭藻组合特征。     

New Eocene dinoflagellate cysts from the southern edge of the Junggar Basin,Xinjiang, China

The Anjihaihe Formation in the southern edge of the Junggar Basin was previously considered a series of freshwater lacustrine depositions. However, abundant marine dinoflagellate cysts were recently recovered from the middle to upper part of the middle member of the formation. Two new genera, six new species and one new subspecies among the abundant dinoflagellate cysts are described and illustrated, i.e. Circulodinium? laeve sp. nov., Kaiwaradinium abbreviatum sp. nov., Spiniferites adnatus subsp. latispinus subsp. nov., Oligosphaeropsis accreta gen. et. sp. nov., Oligosphaeropsis complex gen. et. sp. nov., Oligosphaeropsis megaprocessa gen. et. sp. nov. and Tianshandinium biconicum gen. et. sp. nov. They are rare to common constituents of the dinoflagellate assemblage in the Anjihaihe Formation and may prove useful for regional biostratigraphic correlation and palaeoenvironment re-establishment.     

Synthesis of Methyl (5Z,9Z,17R)-17-Methylnonadeca-5,9-dienoate,the (R)-Enantiomer of the Structure Proposed for a Metabolite of the Philippine Sponge Plakinastrella sp.

The (R)-enantiomer (1) of methyl (5Z,9Z)-17-methyl-nonadeca-5,9-dienoate, the structure proposed for a metabolite of the Philippine sponge, Plakinastrella sp., was synthesized. The ¹H- and ¹³C-NMR spectra of the synthetic material were different from those reported for the natural product. The proposed structure 1 is therefore incorrect.     

A convenient synthesis of a bromotyrosine derived metabolite, psammaplin A, from psammaplysilla sp.

Psammaplin A 1, one of the bromotyrosine metabolites isolated from marine sponge, Psammaplysilla sp., was synthesized in good yield by direct coupling of phenolic oxime-acid 9 and cystamine using a mixture of DCC and N-hydroxyphthalimide in the presence of Et₃N.     

Isoconcinndiol,a brominated diterpenoid from Laurencia snyderae var. Guadalupensis

A new brominated diterpenoid, isoconcinndiol, has been isolated from the marine red alga Laurencia snyderae.     

Immunolocalization of the Toxin Latrunculin B within the Red Sea Sponge Negombata magnifica (Demospongiae, Latrunculiidae)

The location of latrunculin B, the major toxin of the Red Sea sponge Negombata magnifica, was revealed using specific antibodies. Antibodies from rabbits immunized with a conjugate of latrunculin B with keyhole limpet hemocyanin (KLH) were purified over a latrunculin B–Sepharose affinity column. Analysis of immunohistochemical and immunogold-stained sponge sections, using light and transmission electron microscopy, revealed latrunculin B labeling mostly beneath the sponge cortex at the border between the external (ectosome) and internal (endosome) layers (ectosome-endosome border). The endosome was less labeled than the border. Immunogold localization revealed latrunculin B in the sponge cells but not in its prokaryotic symbionts. Archeocytes and choanocytes were significantly more labeled than other cells. The antibodies primarily labeled membrane-limited vacuoles within archeocytes and choanocytes that are perhaps latrunculin B secretory or storage vesicles. Peripheral latrunculin B may have a role in defense against external epibionts, predators, and competitors. Received December 21, 1999; accepted March 5, 2000.     

Tenasogenin,a pregnane ester from Marsdenia tenacissima

A new polyhydroxy pregnane ester named tenasogenin was isolated from the seeds of Marsdenia tenacissima. On the basis of chemical and spectroscopic evidence and identification of its hydrolysis products, its structure has been established as 11α-O-β,β-dimethylacryloyl-3β,12β,14β,20R-tetrahydroxypregn-5-ene.     

鼎湖山国家自然保护区林下土壤微生物新结构生物活性代谢产物的研究进展

鼎湖山国家自然保护区特殊的地理位置和气候条件造就了独特的生态环境,孕育了丰富的植物和微生物资源。为了挖掘其中的微生物资源,对近年来鼎湖山林下土壤来源的真菌和放线菌次生代谢物研究进行了综述。     

The phytoplankton of Crose Mere,Shropshire

The succession of phytoplankton in a small lowland eutrophic lake (mere) over six years is described, with particular reference to the annual occurrence of the dominant forms. Integrated data reveal a seasonal pattern in both the quality and quantity of populations, which typifies the periodicity of the meres in the region but differs in detail from those of temperate eutrophic lakes elsewhere.     

海洋真菌抗污损活性天然产物研究

黏附于海洋船舶或人工设施表面的污损生物给人类海洋生产活动与生态环境带来诸多不利影响.将具有抗污损活性的化合物开发成防污涂料是目前防治海洋生物污损的最常用手段之一.而大量传统有机金属防污剂因其严重毒副作用被禁用,亟须开发高效、环境友好型抗污损涂料.海洋真菌能够产生大量结构新颖、作用机制独特的高效、低毒/无毒抗污损活性次级...