Comparative morphogenesis of the cephalic structures of the acuariid nematodesStammerinema soricis (Tiner, 1951),Antechiniella suffodiax (Beveridge & Barker, 1975) n. g., n. comb. andSkrjabinoclava thapari (Teixeira de Freitas, 1953)

Summary Stammerinema soricis (Tiner, 1951) is reported fromSorex araneus L. from a new geographic locality, Sologne, France. Comparison of the ontogenesis of the cephalic structures of this species with two other acuariids of mammals,S. suffodiax Beveridge & Barker, 1975 andS. thapari (Teixeira de Freitas, 1953), shows that these three species, formerly included in the same genus, represent three distinct genera:Stammerinema Osche, 1955, parasitic in holarctic insectivores;Antechiniella n. g. parasitic in Australian marsupials and rodents; andSkrjabinoclava Sobolev, 1943, parasitic in neotropical carnivores and in birds. The two generaStammerinema andAntechiniella belonging to different subfamilies of the Acuariidae, are derived from acuarioids which have evolved mainly in birds, hosts which harbour ancestral forms. ac]19850610     

Three species of opisthomonorchiine monorchiids (Digenea) in Carangoides spp. (Perciformes: Carangidae) from off New Caledonia, with a description of Opisthomonorchis dinema n. sp.

Three opisthomonorchiinae species are described from fishes obtained at the Fish Market in Nouméa, New Caledonia. Opisthomonorchis dinema n. sp. from Carangoides dinema Bleeker differs from the other recognised species in the genus by the long recurved genital atrium, arcing anteriorly. Also described are Opisthomonorchis carangis Yamaguti, 1952 from Carangoides sp. and Pseudopisthomonorchis thapari (Varma & Singh, 1979) n. comb. for Opisthomonorchis thapari Varma & Singh, 1979 from Carangoides chrysophrys (Cuvier). The features distinguishing Opisthomonorchis Yamaguti, 1952 and Pseudopisthomonorchis Madhavi, 1974 are discussed.     

Two new species of <Emphasis Type="Italic">Cucullanus</Emphasis> Müller, 1777 (Nematoda: Cucullanidae) from marine fishes off Thailand

Based on light and scanning electron microscopical observations, two new species of Cucullanus Müller, 1777 (Nematoda: Cucullanidae) are described from the intestine of marine perciform fishes in the coastal region of the Gulf of Thailand, Thailand: Cucullanus rastrelligeri n. sp. from the short mackerel Rastrelliger brachysoma (Bleeker) (Scombridae) and Cucullanus thaiensis n. sp. from the brownstripe red snapper Lutjanus vitta (Quoy & Gaimard) (Lutjanidae). The former species, C. rastrelligeri, is mainly characterised by an elongate pseudobuccal capsule, the presence of a ventral sucker, markedly short spicules (306–360 μm), a median papilla-like formation on the anterior anal lip and a distinctly elevated posterior anal lip, the location of the deirids and excretory pore, and by the distribution of genital papillae in the male. The latter species, C. thaiensis, is characterised by a broad pseudobuccal capsule, the presence of a ventral sucker and spicules 680 μm long. It is morphologically closest to C. pargi González-Solís, Tuz-Paredez & Quintal-Loria, 2007, but differs from it mainly in the distribution of the genital papillae in the male and apparently larger gravid females, and, whereas C. thaiensis occurs in the West Pacific (Gulf of Thailand), C. pargi was described from the West Atlantic (Caribbean Sea). C. rastrelligeri and C. thaiensis are the first nominal species of cucullanid nematodes reported from marine fishes in Thai waters. Indocucullanus thapari Gupta & Srivastava, 1984 is transferred to Cucullanus as C. thapari (Gupta & Srivastava, 1984) n. comb.     

Revision of the Thelastomatoidea,Oxyurida of invertebrate hosts I. Thelastomatidae

The Family Thelastomidae (Thelastomatoidea; Oxyurida; Nematoda) is revised, genera are diagnosed and a complete list of species is given. The following genera, normally classified in the family, are not included: Linstowiella Basir is considered a member of the Pharyngodonidae and perhaps a synonym of Pharyngodon Diesing; Klossinema Lal is considered a synonym of Cephalobellus Cobb; Schubartnema Kloss is considered a taxonomic chimaera, the male corresponding to Carnoya Gilson and the female probably to Binema Basir. Two new species are proposed: Gryllophila bainae and G. klossae for material assigned to G. skrjabini (Sergiev) by Bain (1965) and Kloss (1959) respectively. The following new synonyms are proposed: Blattellicola Basir and Blatellicoloides Farooqui synonyms of Blatticola Schwenck; Basiriella Ahmed & Jabin synonym of Blattophila Cobb; Leidynema (Basiria) Farooqui synonym of Cranifera Kloss; Posterovulva Van Waerebeke synonym of Desmicola Basir; Oryctophila Van Waerebeke synonym of Johnstonia Basir; Panaesthiana Kloss synonym of Leidynemella Chitwood & Chitwood; Psilocephala Rao synonym of Cameronia Basir; Welchiella Gupta & Kaur synonym of Hammerschmidtiella Chitwood. The following new combinations are proposed: Blattophila basiri for Basiriella basiri Ahmed & Jabin, leaving Blattophila basiri Farooqui pre-occupied (and renamed B. farooquii); Cameronia psilocephala and C. aspiculata for Psilocephala psilocephala Rao and P. aspiculata Farooqui respectively; Corydiella mamba (Van Waerebeke) for Thelastoma mamba; Desmicola moramangi for Posterovulva moramangi Van Waerebeke; Johnstonia morondovae for Oryctophila morondovae; Leidynemella sphaeropoei for Oxyuris sphaeropoei Parona; Thelastoma aurangabadense, T. indica (preoccupied), T. mackenziei, T. thapari, T. unicoloris and T. welchi for Schwenkiella aurangabadense Farooqui, S. indica Rao & Rao, Suifunema mackenziei Zervos, Bulhoesia thapari Singh & Singh, Cephalobellus unicoloris Van Waerebeke and Schwenkiella welchi Farooqui, respectively.     

Bud structure and resprouting in coppiced stools of Salix viminalis L., S. eriocephala Michx., and S. amygdaloides Anders

Fast-growing willows are cultivated as coppice in short rotation biomass plantations. The production and sustainability of the system is based on the ability of trees to resprout after repeated harvesting. The large variation in coppicing ability is due to plant genotypic differences in structure and physiology as well as environmental factors. Morphological and structural prerequisites for resprouting were compared in two shrubby willows with high coppicing ability, S. viminalis and S. eriocephala, and one tree-formed species, S. amygdaloides, with low coppicing ability. The initiation and development of buds and the resprouting pattern of coppiced stools were compared. All buds were axillary in origin and showed the same principal structure consisting of one main shoot primordium and two lateral primordia. In S. viminalis and S. eriocephala the lateral buds contained several leaf primordia and sprouted shortly after the main bud. In S. amygdaloides further development of lateral buds was inhibited after formation of two budscales, and leaf primordia were not formed until the buds were forced to sprout. The number of sprouts developing after coppicing were correlated to the structure and number of buds and their position on the stools. Self-thinning rate was high and many shoots originating from lateral buds died. Most buds were located above ground on the remaining basal portions of harvested stems. No adventitious buds were found on the stools. Significantly different bud differentiation pattern and frequent sylleptic sprouting resulted in lower coppice response in S. amygdaloides compared to S. viminalis and S. eriocephala.     

Chromatin structures of Kluyveromyces lactis centromeres in K. lactis and Saccharomyces cerevisiae

We have investigated the chromatin structure of Kluyveromyces lactis centromeres in isolated nuclei of K. lactis and Saccharomyces cerevisiae by using micrococcal nuclease and DNAse I digestion. The protected region found in K. lactis is approximately 270 bp long and encompasses the centromeric DNA elements, KlCDEI, KlCDEII, and KlCDEIII, but not KlCDE0. Halving KlCDEII to 82 bp impaired centromere function and led to a smaller protected structure (210 bp). Likewise, deletion of 5 bp from KlCDEI plus adjacent flanking sequences resulted in a smaller protected region and a decrease in centromere function. The chromatin structures of KlCEN2 and KlCEN4 present on plasmids were found to be similar to the structures of the corresponding centromeres in their chromosomal context. A different protection pattern of KlCEN2 was detected in S. cerevisiae, suggesting that KlCEN2 is not properly recognized by at least one of the centromere binding proteins of S. cerevisiae. The difference is mainly found at the KlCDEIII side of the structure. This suggests that one of the components of the ScCBF3-complex is not able to bind to KlCDEIII, which could explain the species specificity of K. lactis and S. cerevisiae centromeres.     

Leaf structure of Syzygium spp. (Myrtaceae) in relation to site affinity within a tropical rain forest

This study examined four species of Syzygium (S. firmum, S. makul, S. operculatum, S. rubicundum) Myrtaceae, a tree genus that dominates the canopy of rain forests of south‐west Sri Lanka. Syzygium spp. occupy differing habitats with relation to succession and forest topography. We examined differences in leaf morphology and physiology in response to amount of shade, an important environmental variable affecting Syzygium distribution within the forest. To study change in leaf structure and physiology, environmental shelters were constructed simulating forest shade that differed in quality, quantity and duration. Seedlings were exposed to: (i) 0% shade (full sun, FS), red : far red (R : FR) ratio 1.27; (ii) 65% shade (large opening, LO) with direct sunlight similar to the centre of a large canopy opening, R : FR ratio 1.27; (iii) 82% shade (small opening, SO) with direct sunlight similar to the centre of a small canopy opening, R : FR ratio 1.27; (iv) 58% uniform light shade (LS) with a quality similar to the outside edge of a large canopy opening, R : FR ratio 1.05; (v) 85% uniform medium shade (MS) with a quality similar to the inside forest edge of a large canopy opening, R : FR ratio 0.97; (vi) 99% uniform deep shade (DS) similar to that of the forest understorey, R : FR ratio 0.23. The shelters were constructed in a large open area at the field station of the Sinharaja World Heritage site, Sri Lanka. Seedlings of each species were grown for two years in their respective shade treatments before physiological, morphological and anatomical measurements were made on leaves. Variation in leaf structure and physiology between the species was associated with differences in shade‐tolerance and water‐use. All species increased in photosynthesis rates and dimensions in leaf structure (leaf blade and cuticle thickness, stomatal density, thickness of upper and lower epidermis, and thickness of palisade mesophyll) with decrease in shade. In contrast, stomatal conductivity was highest in the DS (99% shade) treatment. Leaves of Syzygium firmum were thickest and largest in area. S. firmum also had highest photosynthesis in the SO (82% shade) treatment. S. firmum was the most shade‐tolerant of all species: it grows well in low shade and its leaf structure suggests it to be the most conservative in water‐use of the Syzygium spp. In the forest S. firmum can persist in the forest shade as established seedlings, but grows best within canopy openings of late‐seral rain forest. Leaves of S. operculatum were thinnest but had highest stomatal densities of the four species. S. operculatum is considered shade‐intolerant, with a leaf structure suggesting it to be prone to desiccation, and by implication susceptible to drought. S. operculatum is found along streams within early seral rain forest habitat, often originating on stream banks after land clearance for cultivation. In the FS (0% shade) treatment, S. rubicundun had highest photosynthesis rates and greatest number of leaves but smallest leaf area of the Syzygium species. S. rubicundum is more shade‐intolerant but more efficient in water‐use than S. operculatum. S. rubicundum is a mid‐seral canopy tree of the midslope stands that are thought to have originated after catastrophic windthrows or swidden cultivation. The leaf physiology and structure of S. makul suggests it to be both moderately shade‐tolerant and conservative in water‐use. It is the most widely distributed Syzygium species across the topography of late‐seral rain forest. We suggest forest disturbance and hydrology are important environmental factors that influence distribution of Syzygium species across the topography. Results from this study contribute to a body of knowledge suggesting that canopy tree species of rain forests in south‐west Sri Lanka have discrete affinities to topography and differences in successional status, and that adaptations in leaf structure and physiology are indicative of such phenomena. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 141 , 365–377.     

Development of microsatellite markers for Stachyurus macrocarpus and Stachyurus macrocarpus var. prunifolius (Stachyuraceae), critically endangered shrub species endemic to the Bonin Islands

Stachyurus macrocarpus and S. macrocarpus var. prunifolius are critically endangered shrub species in the Bonin (Ogasawara) Islands, Japan. These species are extremely rare, and the numbers of individuals in wild populations are 68 in S. macrocarpus and 13 in S. macrocarpus var. prunifolius. For the investigation of genetic diversity, genetic structure and relatedness among remnant individuals of these endangered species, we developed eight microsatellite markers from S. macrocarpus var. prunifolius and characterized these markers for S. macrocarpus var. prunifolius and S. macrocarpus using all naturally occurring individuals of these species. The expected heterozygosities of these markers ranged from 0.14 to 0.67 in S. macrocarpus var. prunifolius, and from 0.02 to 0.84 in S. macrocarpus. The markers described here will be useful for investigating the genetic diversity, genetic structure and relatedness among remnant individuals, and planning the restoration of these critically endangered species.     

Sphagnum divinum (sp. nov.) and S. medium Limpr. and their relationship to S. magellanicum Brid.

Sphagnum magellanicum has been viewed as being a predominantly circumpolar species in the northern hemisphere, but it occurs in the southern hemisphere and was originally described from the southern parts of Chile. It is an ecologically important species in mire ecosystems and has been extensively used as a model to study processes of growth, carbon sequestration and peat decomposition. Molecular and experimental studies have, however, revealed genetic structure within S. magellanicum, and morphological differences associated with these genetic groups. Here we describe Sphagnum divinum in Sphagnum subgenus Sphagnum (Sphagnaceae, Bryophyta) as a new species, based on molecular and morphological evidence. Sphagnum medium is reinstated as a distinct species and is epitypified. Consequently, a new species concept of S. magellanicum is presented including an epitypification. Important morphological characters to separate these three species in the field and under the microscope are presented. Ecology and distribution differ among the species; S. divinium has a wide habitat range including mire margin, forested peatlands and moist heaths, and a circumpolar distribution around the northern hemisphere. Sphagnum medium seems to be more restricted to ombrotrophic mire expanse habitats and shows an amphi-Atlantic distribution in the northern hemisphere. Sphagnum magellanicum has a very broad ecological niche in peatlands and is found in most mire habitats in Tierra del Fuego on the southern tip of South America.     

Phylogeny of Sibling Species of Simulium venustrum and S. verecundum (Diptera: Simuliidae) Based on Sequences of the Mitochondrial 165 rRNA Gene

The phylogeny of four sibling species of Simulium venustum (CC, CC3, CC4, and AC(gB)) and two sibling species of S. verecundum (AA and ACD = S. rostratum) was reconstructed using nucleotide sequences of the mitochondrial large subunit rRNA gene. Separate phylogenetic analyses were performed by dividing the sequence data into: (1) helices of a computer-generated secondary structure of the rDNA; (2) loops of the computer-generated structure; (3) helices of a consensus secondary structure (deduced by comparing the computer-generated structure of black flies with the corresponding structures proposed for the fruit fly (Drosophila yakuba) and the mosquito (Aedes albopictus)); (4) loops of the consensus structure; (5) both helices and loops of the consensus secondary structure; and (6) the entire sequence regardless of secondary structure, including 11 variable sites in regions where the prediction of secondary structure was not possible. We found that different data sets led to different phylogenetic conclusions. The phylogenies based on data sets 4 and 6 were consistent with nonmolecular evidence, while the phylogenies based on other data sets were not. Our study suggests S. decorum, a morphospecies, might have shared a common ancestor with sibling species of S. venustum.     

群落演替对夏蜡梅种群分布和数量的影响

对夏蜡梅(Sinocalycanthus chinensis(Cheng et S.Y.Chang)Cheng et S.Y.Chang)所有分布地(浙江临安、天台和安徽绩溪)进行了详细调查,分析夏蜡梅种群面积、密度、结构和群落特征等,并与前人调查结果对比,阐明群落演替对夏蜡梅种群的影响。10余年来,由于国家相关政策的实施(退耕还林、天然林保护以及自然保护区的建立等)以及夏蜡梅分布地林地经营模式的改变,不同夏蜡梅群落呈现发展演替的不同状态,从而对夏蜡梅种群产生了显著影响。从群落类型来看,较为稳定的种群为大明山、西坑、白水坞、捣臼孔种群,种群结构为增长型或稳定型,群落处于乔木或顶级乔木阶段,原生植被保存较好,生境相对稳定,各物种在长期竞争中趋于稳定;直源种群为严重衰退的种群,群落经历了从灌丛阶段向灌乔阶段演化,原来同层次的常绿乔木逐渐形成密集的乔木层,郁闭度高,造成夏蜡梅生长不良甚至死亡,幼苗缺少或数量少,更新困难,此区域的夏蜡梅呈逐渐退化消亡趋势;而溪古坪、龙塘山种群所处群落正是属于这种群落演替的早期阶段,处于衰退过程中种群,不加人工干预也会逐渐退化;而双石边、经过坪等种群虽目前数量多,分布集中,更新良好,但变数最大,一旦人工干扰加剧或消除,则种群结构将快速发生变化,走向消亡的几率极大。该研究结果可为夏蜡梅保护提供科学依据。     

COLEOFASCICULUS GEN. NOV. (CYANOBACTERIA): MORPHOLOGICAL AND MOLECULAR CRITERIA FOR REVISION OF THE GENUS MICROCOLEUS GOMONT1

Species currently classified within the cyanobacterial genus Microcoleus were determined to fall into two distinct clades in a 16S rDNA phylogeny, one containing taxa within the Oscillatoriaceae, the other containing taxa within the Phormidiaceae. The two lineages were confirmed in an analysis of the 16S–23S internal transcribed spacer (ITS) region sequences and secondary structures. The type species for Microcoleus is M. vaginatus Gomont, and this taxon belongs in the Oscillatoriaceae. Consequently, Microcoleus taxa in the Phormidiaceae must be placed in separate genera, and we propose the new genus Coleofasciculus to contain marine taxa currently placed in Microcoleus. The type species for Coleofasciculus is the well‐studied and widespread marine mat‐forming species Microcoleus chthonoplastes (Mert.) Zanardini ex Gomont. Other characters separating the two families include type of cell division and thylakoid structure.     

Comparison of genetic (co)variance matrices within and between Scabiosa canescens and S. columbaria

In the current study, we used bootstrap analyses and the common principal component (CPC) method of Flury (1988) to estimate and compare the G ‐matrix of Scabiosa columbaria and S. canescens populations. We found three major patterns in the G ‐matrices: (i) the magnitude of the (co)variances was more variable among characters than among populations, (ii) different populations showed high (co)variance for different characters, and (iii) there was a tendency for S. canescens to have higher genetic (co)variances than S. columbaria. The hypothesis of equal G ‐matrices was rejected in all comparisons and there was no evidence that the matrices differed by a proportional constant in any of the analyses. The two ‘species matrices’ were found to be unrelated, both for raw data and data standardized over populations, and there was significant between‐population variation in the G ‐matrix in both species. Populations of S. canescens showed conservation of structure (principal components) in their G ‐matrices, contrasting with the lack of common structure among the S. columbaria matrices. Given these observations and the results from previous studies, we propose that selection may be responsible for some of the variation between the G ‐matrices, at least in S. columbaria and at the between‐species level.     

A widespread cyanobacterium supported by polyphasic approach: proposition of Koinonema pervagatum gen. & sp. nov. (Oscillatoriales)1

Several new genera originally classified as the genus Phormidium, a polyphyletic and taxonomically complex genus within the Oscillatoriales, were recently described. The simple morphology of Phormidium does not reflect its genetic diversity and the delimitation of a natural group is not possible with traditional classification systems based on morphology alone. Therefore, this study used morphological, ecological, and molecular approaches to evaluate four populations morphologically similar to Ammassolinea, Kamptonema, and Ancylothrix (simple, curved, and gradually attenuated at the ends trichome), found in subtropical and tropical Brazilian regions. 16S rRNA gene sequences grouped all the strains in a highly supported clade with other two European strains isolated from thermal springs surrounding areas. The 16S‐23S ITS secondary structure corroborated the phylogenetic analysis with all the strains having similar structures. Consequently, a genetically well‐defined and cryptic new genus, Koinonema gen. nov., is proposed containing the aquatic, mesophilic, and morphologically homogeneous new species, Koinonema pervagatum sp. nov.     

Edaphic diatom communities associated with Spartina alterniflora and S. patens in New Jersey

Edaphic diatoms inhabiting the sediments beneath dwarf Spartina alterniflora Loisel. and S. patens (Ait.) Muhl. in Great Bay salt marsh, Tuckerton, New Jersey were collected from 24 September 1974 through 20 August 1975. Of the 91 taxa encountered, 8 were endemic to the dwarf S. alterniflora habitat and 42 endemic to the S. patens habitat. The edaphic diatom community associated with S. patens was comprised of a much greater number of taxa and possessed higher values for species diversity (H') and evenness (J') than the community associated with dwarf S. alterniflora. The salinity of the marsh surface showed a completely opposite trend, being greatly reduced at the S. patens habitat. A highly significant relationship (P < 0.001) between the number of diatom taxa and marsh surface salinity at the S. patens habitat was demonstrated by a least squares regression. This finding led to the conclusion that the dissimilarity in the structure of the two edaphic diatom communities was primarily due to the very low marsh surface salinities at the S. patens habitat from January through June, and that this sustained. low-salinity regime allowed a very large number of taxa to coexist only in the S. patens community. Comparison of the diatom flora of Great Bay salt marsh with that of a Delaware marsh studied previously by the author showed that 67.0% of the 91 taxa encountered in New Jersey also occur on the Delaware marsh.     

Direct differential absorbance profiles of denaturing transitions in ribosomal and mRNA.

A direct method for measuring the derivative of thermal transition profiles (ΔA/ΔT), first described by Pavlov and Lyubchenko [Biopolymers 17 , 795–798 (1978)], is applied to the secondary structure of several eukaryotic ribosomal and messenger RNAs. The method consists of generating an effective ΔT between a sample and reference cuvette by altering the T_m (midpoint denaturation temperature) of one of the solutions with respect to the other. This can be done by changing salt concentration, solvent, pH, or ligands. Scanning the two cuvettes by varying the wavelength at different temperatures permits detailed examination of the base composition of differentially melting domains. We report here the ΔA/ΔT profiles generated by monovalent ion concentration differences for a number of high-molecular-weight natural RNAs, as well as the synthetic polynucleotides poly(rA) and “random” poly[r(A,G,U,C)]. The 18S and 28S rRNAs from chick embryos exhibit a reproducible series of peaks in the ΔA/ΔT profiles at low salt with ΔT = 4K. The high-temperature transitions in 28S rRNA appear to contain G·C base pairs exclusively, in contrast to those in 18S rRNA or any natural mRNA. Each mRNA we have examined (bacteriophage MS2, globin mRNA from rabbit reticulocytes, and procollagen mRNA from chick embryos) exhibits a distinctive ΔA/ΔT profile in low salt. The stability of many of the transitions in each of the mRNAs is no greater than that of the secondary structure in random poly(A,G,U,C) in low salt. More than 50% of the base pairing in procollagen mRNA actually “melts” below the mean for the random copolymer, indicating that despite its high G·C content, this mRNA contains a secondary structure that is exceptionally low in stability.     

Monogenea of Chinese marine fishes. XIV. Two new species of Microcotylidae from fishes of the South China Sea

Two new species of microcotylid monogeneans are described. Solostamenides platyorchis n. sp. was obtained from the gills of Mugil cephalus (Mugilidae) and Polylabroides guangdongensis n. sp. from the gills of Sparus macrocephalus, S. berda and Acanthopagrus latus (Sparidae). Solostamenides platyorchis is morphologically similar to S. mugilis (Vogt, 1878) Unnithan, 1971 and S. pseudomugilis (Hargis, 1956) Unnithan, 1971 in the structure of the copulatory organ, but differs from them in the number, arrangement and shape of the testes. Features of P. guangdongensis distinguishing it from other species of the genus include a copulatory organ lacking small spines and an extremely long polar filament on the egg. In view of this species, we suggest omitting the presence of small spines on the copulatory organ as a diagnostic character of the genus Polylabroides Mamaev & Parukhin, 1976.     

海绵来源链霉菌S52-B中氨酰胺天然产物的分离与鉴定

【背景】海洋微生物是复杂海洋生态环境中重要的生物资源之一。海洋微生物所产生的活性天然产物极为丰富,是药物或药物先导化合物的重要来源。【目的】探索海洋中海绵来源链霉菌Streptomycessp.S52-B的优势生长条件,挖掘其次级代谢产物,以期分离具有良好生物活性的天然产物。【方法】根据"One Strain Many Compounds"(OSMAC)策略,寻找利于Streptomyces sp. S52-B生长和次级代谢产物产生的优势培养基,结合质谱及特征性的紫外吸收谱图,选择培养基进行大量发酵。利用正相硅胶柱色谱、葡聚糖凝胶柱色谱和制备型高效液相色谱等进行分离纯化,并应用高分辨质谱和核磁共振光谱进行化合物结构解析。【结果】确定培养基A–D为海洋链霉菌S52-B的优势培养基,基于紫外吸收光谱与质谱分析,从培养基A的大量发酵物中分离鉴定3个具有吡咯并[4,3,2-de]喹啉核心结构的含氯化合物,属于氨酰胺类天然产物,其中Ammosalic acid为新结构化合物。【结论】已知含有吡咯并喹啉母核的氨酰胺类家族化合物具有优良的抗癌活性。本研究从海绵来源链霉菌S52-B中分离鉴定了3个氨酰胺类化合物,其中一个是新结构化合物,不仅丰富了此类化合物家族的结构类型,也为研究其生物合成途径中的未知机理奠定了基础,还有利于结合培养条件和基因组信息从这株海绵来源链霉菌中挖掘新结构的活性天然产物。     

Validation of Hygrohypnum Lindb. sect. Dilatatae Szafr.

Abstract

A number of chemical habitat parameters for the species Scorpidium scorpioides, S. cossonii and S. revolvens were investigated in three areas in northern and southern Sweden. S. revolvens occurs in a much narrower range of some parameters, especially pH and conductivity, than the other two species. When pH and conductivity are considered together, S. revolvens and S. cossonii are almost completely mutually exclusive.