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1.
Summary. The paper describes two methods of the synthesis of ethyl (3R,4S)- and (3S,4S)-4-[(benzyloxycarbonyl)amino]-5-[(tert-butyloxycarbonyl)amino]-3-hydroxypentanoates, useful for the syntheses of edeine analogs. Differently N-protected (S)-2,3-diaminopropanoic acid was used as a substrate in both procedures. The absolute configuration of newly generated asymmetric
carbon atoms C-3 in β-hydroxy-γ,δ-diamino products was assigned by means of 1H NMR spectroscopy after their transformation into corresponding piperidin-2-ones.
Received May 24, 2002 Accepted October 10, 2002 Published online December 18, 2002
Acknowledgment The authors are indebted to the Faculty of Chemistry, Technical University of Gdańsk for financial support.
Authors' address: Zbigniew Czajgucki, M. Sc., Department of Pharmaceutical Technology and Biochemistry, Faculty of Chemistry, Technical University
of Gdańsk, 11/12 Narutowicza St., 80-952 Gdańsk, Poland, Fax +48 58 347 11 44, E-mail: zmczaj@wp.pl 相似文献
2.
H. Takahashi 《Mycoscience》2002,43(4):0343-0350
Four new species of Crinipellis and Marasmius (Agaricales, Basidiomycetes) in eastern Honshu, Japan, are described and illustrated: (1) Crinipellis conchata sp. nov. (section Excentricinae), forming a conchate pileus and a strongly excentric, short stipe, was found on a dead twig of Trachelospermum asiaticum in Mt. Takao, Tokyo; (2) Marasmius funalis sp. nov. (section Androsacei), forming a densely white-hispid, dark brown stipe bearing numerous setiform caulocystidia, was found on a dead twig of Cryptomeria japonica or on leaf litter in Tokyo and Kanagawa; (3) Marasmius maculosus sp. nov. (section Sicci), having a relatively large, reddish-brown pileus distinctly mottled with pale colored spots and Siccus-type cheilocystidia and pileipellis cells with relatively long setulae, was found on leaf litter in the lowland forest of
Kanagawa and Chiba; and (4) Marasmius sasicola sp. nov. (section Marasmius), having a small, plicate-sulcate pileus, a filiform, wiry, blackish stipe, collariate lamellae, and Siccus-type cheilocystidia and pileipellis elements, was found on fallen dead leaves of grass bamboo in Kanagawa.
Received: January 30, 2002 / Accepted: May 24, 2002 相似文献
3.
Appearance and location of 45S rDNA and 5S rDNA signals were compared in chromosomes of nine species of the aneuploid Zamia and their taxonomically and phylogenetically closely related Ceratozamia mexicana. The 45S rDNA signal was detected in the proximal region of six chromosomes in Zamia angustifolia, Z. integrifolia, Z. pumila and Z. pygmaea (all 2n=16); in the proximal region of 6–14 chromosomes in Z. furfuracea, Z. loddigesii, Z. skinneri and Z. vazquezii (all 2n=18); and on the proximal region of 20 chromosomes in Z. muricata (2n=23). The 5S rDNA signals were commonly seen near the terminal region of the short arm of two metacentric chromosomes
in the four species with 2n=16 and Z. furfuracea, Z. loddigesii and Z. vazquezii with 2n=18. Other 5S rDNA signals were seen near the terminal region of two terminal-centromeric chromosomes in Z. skinneri and near the terminal region of a metacentric and a telocentric chromosomes in Z. muricata. In contrast, those with 45S and 5S rDNA signals were exhibited in chromosomes of Ceratozamia mexicana in a different manner from those in the nine species of Zamia; the 45S rDNA signal in the terminal region of four metacentric and two submetacentric chromosomes and the 5S rDNA signal
near the proximal region of two metacentric chromosomes.
Received November 1, 1999 Accepted January 10, 2001 相似文献
4.
Summary. This review article focuses on the synthesis and reactions of N,N-di-Boc glutamate and aspartate semialdehydes as well as related aldehydes. These building blocks are prepared according to
various strategies from glutamic and aspartic acids and find interesting synthetic applications. In the first part, the methods
for the synthesis of N,N-di-Boc-amino aldehydes are summarized. The applications of these chiral synthons for the synthesis of unnatural amino acids
and other bioactive compounds are discussed in the second section.
Received April 24, 2002 Accepted August 13, 2002 Published online January 30, 2003
Authors' address: Prof. Violetta Constantinou-Kokotou, Chemical Laboratories, Agricultural University of Athens, Iera Odos 75, 11855 Athens,
Greece, E-mail: vikon@aua.gr
Abbreviations: AcNH-TEMPO, 4-acetamido-2,2,6,6-tetramethyl-1-piperidinyloxy free radical; AIBN, 2,2′-azobis(2-methylpropionitrile); Aliquat,
methyltrioctylammonium chloride; Bn, benzyl; Boc, tert-butoxycarbonyl; But, tert-butyl; m-CPBA, 3-chloroperoxybenzoic acid; DAST, diethylaminosulfur trifluoride; DBU, 1,8-diazabicyclo[5.4.0]undec-7-ene; (R,R)-(+)-DET, (R,R)-(+)-diethyltartrate; DIBALH, diisobutyl aluminium hydride; DMAP, 4-dimethylaminopyridine; DMF, dimethylformamide; Et3N, triethylamine; KHMDS, potassium bis(trimethylsilyl)amide; (S)-LLB, lanthanium-lithium-bis-metallic binaphthol catalyst; MsCl, methanesulfonyl chloride; NEM, N-ethylmorpholine; NMO, 4-methylmorpholine N-oxide; PPA, propylphosphonic acid anhydride; TBHP, tert-butyl hydroperoxide; TFA, trifluoroacetic acid; THF, tetrahydrofuran; TMSI, 1-(trimethylsilyl)imidazole; Trt, trityl. 相似文献
5.
Pseudolagarobasidium calcareum (Basidiomycotina, Corticiaceae s.l.) is newly reported for Japan, and its cultural characteristics are described for the
first time. Seven of nine Japanese and Taiwanese specimens examined produce arthroconidia associated with the basidiomata.
Variability in color of the hymenial surface is also observed among the specimens. In culture, this species is characterized
by fiber hyphae (quasi-binding hyphae) and arthroconidia. Mating tests reveal a multiallelic, bifactorial incompatibility
system of this fungus and intercompatibility between Japanese and Taiwanese strains. This species resembles Pseudolagarobasidium subvinosum but differs in producing the fiber hyphae not only in culture but also in the basidiomata.
Received: July 10, 2001 / Accepted: March 29, 2002 相似文献
6.
The chemotactic and chemokinetic activities in zoospores of Saprolegnia parasitica NJM 8604 (= H2) were examined using various amino acids, carbohydrates, fatty acids, and fish tissue extracts to estimate
one of the important factors for attachment of zoospores to their host. All the tested six amino acids showed strong chemotactic
reactions whereas carbohydrates and fatty acids caused moderate or strong chemotactic reactions. The chemokinetic activities
against amino acids and carbohydrates were moderate or weak, whereas almost all fatty acids showed negative chemokinetic responses.
Almost all tested fish tissue showed moderate chemotactic response and weak or moderate chemokinetic responses. Generally,
chemotactic activity was strong in the amino acids, and the strongest activity was observed in alanine. Based on these facts,
we considered that zoospores may react against amino acids of the fish body to attach and establish their colonization.
Received: January 10, 2001 / Accepted: December 12, 2002
Correspondence to:K. Hatai 相似文献
7.
Khomaini Hasan Wangsa Tirta Ismaya Idar Kardi Yandi Andiyana Susanti Kusumawidjaya Safri Ishmayana Toto Subroto Soetijoso Soemitro 《Biologia》2008,63(6):1044-1050
α-Amylase from Saccharomycopsis fibuligera R-64 was successfully purified by butyl Toyopearl hydrophobic interaction chromatography, followed by Sephadex G-25 size
exclusion and DEAE Toyopearl anion exchange chromatography. The enzyme has a molecular mass of 54 kDa, as judged by SDS PAGE
analysis. Upon tryptic digestion, two major fragments with relative molecular masses of 39 kDa and 10 kDa, which resemble
the A/B and C-terminal domains in the homologous Taka-amylase, were obtained and were successfully separated with the Sephadex
G-50 size exclusion column. The 39-kDa fragment demonstrated a similar amylolytic activity to that of the undigested enzyme.
However, it was found that the K
m value of the 39-kDa fragment was about two-times higher than that of the undigested enzyme. Moreover, thermostability studies
showed a lower half-life time for the 39-kDa fragment. These findings suggest that the 39-kDa fragment is the catalytic domain,
while the 10-kDa fragment is the C-terminal one, which plays a role in thermostability and starch binding. Although the undigested
enzyme is able to act on raw starches at room temperature, with maize starches as the best substrate, neither the undigested
enzyme nor the fragments adsorb the tested raw starches. These results propose Saccharomycopsis fibuligera α-amylase as a raw starch-digesting but not adsorbing amylase, with a similar domain organization to that of Taka-amylase A. 相似文献
8.
Mario C. N. Saparrat Geraldine E. Fermoselle Sebastián A. Stenglein Mónica B. Aulicino Pedro A. Balatti 《Mycopathologia》2009,168(1):41-47
Pseudocercospora griseola is the causal agent of angular leaf spot of common bean (ALS). It has undergone parallel coevolution with its host and two
major groups have been defined, “Andean” (P. griseola f. griseola) and “Mesoamerican” (P. griseola f. mesoamericana). The aim of this study was to analyze the nature and the level of the dark pigment synthesized by the representatives of
each group. After 21 days of incubation on potato dextrose agar medium, P. griseola f. griseola isolate S3b developed colonies with diameters of 17.5 ± 1.3 mm and concentric rings of pigmentation. Isolate T4 of P. griseola f. mesoamericana presented smaller colonies (9.9 ± 0.3 mm) with a uniform dark-gray color. Both isolates, S3b and T4, produced the same pigment,
a 1,8-dihydroxynaphthalene-melanin, although different in quantity and structural features as suggested by the IR spectrum.
The P. griseola f. griseola isolate S3b had a higher growth rate and melanin content as well as smaller sensitivity to melanin synthesis inhibitors compared
to the isolate T4 of P. griseola f. mesoamericana. These results suggest a possible link between melanin and growth in P. griseola. 相似文献
9.
L. Y. Solís-Ramos T. González-Estrada S. Nahuath-Dzib L. C. Zapata-Rodriguez E. Castaño 《Plant Cell, Tissue and Organ Culture》2009,96(3):279-287
Capsicum chinense is a recalcitrant species for in vitro morphogenesis, and up to date there is no efficient system for genetic transformation
and regeneration of this species via somatic embryogenesis. Here, we carried out an in vitro transformation of C. chinense via Agrobacterium tumefaciens co-cultivation with a system that expresses the heterologous gene WUSCHEL from Arabidopsis thaliana. WUSCHEL has been shown to promote the transition from vegetative to embryogenic state when overexpressed. We tested if the expression
of WUSCHEL in C. chinense would promote an embryogenic response in this species. After 15 days of induction, the segments of transformed stems begun
to form globular structures, suggesting that heterologus WUSCHEL was active and involved in the process of morphogenesis. 相似文献
10.
Umbelopsis gibberispora is described as a new species in the genus Umbelopsis, Umbelopsidaceae, Mucorales. The species differs from others in this genus by ellipsoidal sporangiospores with unilaterally
thickened walls. Phylogenetic analyses based on nuclear large subunit ribosomal DNA (nLSU rDNA) partial sequences suggest
that U. gibberispora, U. swartii, and U. westeae form a clade together with the strains of Umbelopsis ramanniana. The ex-type strain of Micromucor ramannianus var. angulisporus is found to be very close to Umbelopsis vinacea, whereas other isolates identified under the former name in the sense of Linnemann fall in the U. ramanniana subclade. For these isolates, a new species, Umbelopsis angularis, is introduced. Phylogenetic relationships among Umbelopsis species are discussed related to their attributes of the sporangial wall and mature spore shapes.
Received: August 27, 2002 / Accepted: March 11, 2003
Acknowledgments We thank Dr. Takashi Ohsono, Graduate School of Agriculture, Kyoto University, Japan, for providing the strain of U. gibberispora (CBS 109328). We also thank Dr. Wieland Meyer, University of Sydney, Australia for access to the phylogenetic tree based
on ITS sequence data before publishing, and Dr. Richard C. Summerbell, Centraalbureau von Schimmelcultures, the Netherlands,
for linguistic corrections. 相似文献
11.
There are three most important bacterial causative agents of serious infections that could be misused for warfare purposes:
Bacillus anthracis (the causative agent of anthrax) is the most frequently mentioned one; however, Fracisella tularensis (causing tularemia) and Yersinia pestis (the causative agent of plague) are further bacterial agents enlisted by Centers for Disease Control and Prevention into the category A of potential biological weapons. This review intends to summarize basic information about these bacterial
agents. Military aspects of their pathogenesis and the detection techniques suitable for field use are discussed. 相似文献
12.
N. Yu. Markelova 《Microbiology》2010,79(6):777-779
Interaction of Bdellovibrio bacteriovorus 100NCJB with bacteria Campylobacter jejuni (strains 1, 2, 3, 4, and 5) and Helicobacter pylori, strain TX30a, was confirmed. The results indicate that lytic activity of bdellovibrios both in liquid media and cells attached
to a surface was observed. The potential use of the antimicrobial activity of predatory bacteria for environmental bioprotection
and public health is discussed. 相似文献
13.
N.-S. Cho E. Malarczyk G. Nowak M. Nowak J. Kochmanska-Rdest A. Leonowicz S. Ohga 《Mycoscience》2002,43(3):0267-0270
Peroxidase and laccase activities increased rapidly up to the formation of primordia and then declined throughout the entire
stage of fruiting. In the case of Pleurotus ostreatus, the level of Mn-dependent peroxidase was very low in primordia and fruiting stages but gradually increased with the growth
of the fruit-body, whereas no activity was detected in Pleurotus sajor-caju during all growth stages. Superoxide dismutase activity was observed mainly at the fruiting stages. These results show that
changes in concentration of lignin-related enzymes are associated with the fruiting process.
Received: December 11, 2000 / Accepted: March 28, 2002 相似文献
14.
The presence of litter has the potential to alter the population dynamics of plants. In this paper, we explore the effects
of litter on population dynamics using a simple experimental laboratory system with populations of the annual crucifer, Cardamine pensylvanica. Using a factorial experiment with four densities and three litter levels, we determined the effect of litter on biomass
and plant fecundity, and the life stages responsible for these changes in yield. Although litter had significant effects on
seed germination and on seedling survivorship, we show, using a population dynamics model, that these effects were not demographically
significant. Rather, the potential effect of litter on population dynamics resulted almost entirely from its effect on biomass.
Persistent litter suppressed plant biomass and apparently removed the direct density effect present in the absence of litter.
Thus, litter changed the shape of the recruitment curve from slightly humped to asymptotic. In addition to changing the shape
of the recruitment curve, litter reduced the carrying capacity of the populations. Thus, the population dynamics model indicated
that not all statistically significant responses were dynamically significant. Given the potential complexity of litter effects,
simple population models provide a powerful tool for understanding the potential consequences of short-term responses.
Received: 8 September 1999 / Accepted: 5 April 2000 相似文献
15.
O. V. Golovanova V. I. Konenkov A. V. Shevchenko M. V. Smolnikova 《Russian Journal of Genetics》2009,45(8):981-986
Based on population analysis of the DRB1, DQA1, DQB1 and TNFA allele frequency distribution patterns, regional features of immunogenetic structure of the population of West Siberia were
investigated. Statistically significant linkage disequilibrium within the HLA class II region, as well as between the TNFA and DRB1, DQA1, and DQB1 was demonstrated. Population frequency distribution patterns of two- and multilocus haplotypes were examined. 相似文献
16.
17.
18.
To overexpress the chitosanase gene (csn) in F. solani, a vector based on pCAMBIA 1300 was constructed. The csn gene, which is under control of the Aspergillus nidulans
gpdA promoter and A. nidulans trpC terminator, was introduced back into the F. solani genome by Agrobacterium tumefaciens-mediated transformation, and the herbicide-resistance gene bar from Streptomyces hygroscopicus was used as the selection marker. Transformants which showed a significant increase in chitosanase production (~2.1-fold
than control) were obtained. Southern blot analysis indicated that most transformants had a single-copy T-DNA integration. 相似文献
19.
Y. L. Dupont 《Population Ecology》2002,44(3):0293-0297
I have investigated the reproductive biology of four dioecious species of Lindera in Japan: Lindera obtusiloba Bl., L. umbellata Thunb., L. erythrocarpa Makino, and L. glauca Bl. The sex ratios in populations of the first three species are close to equality, but in L. glauca only female individuals are found in Japan, although males are known from continental Asia. The persistence of this dioecious species in the absence of males is surprising, and prompts the question: What mechanisms operate to ameliorate problems of colonization in species of Lindera? I carried out bagging experiments in order to test for apomixis (asexual reproduction by seeds) and to establish the importance of pollination and fertilization, and potential pollen vectors. Only L. glauca reproduced by apomixis. Level of fruit set was high, and was not affected by pollination. In the other three species, seed set was entirely dependent on pollen transfer, which could be accomplished by small Coleoptera and Diptera. The evolution of apomixis in L. glauca appears to have been a strategy to overcome sterility and establish a population in the Japanese islands even in the absence of males. However, this change in breeding system has not occurred in congeneric, co-occurring species, which do not seem to have experienced a lack of male plants. 相似文献
20.
Hiroyoshi Kubo 《Mycoscience》2009,50(5):400-406
Pilobolus crystallinus shows unique photoresponses at various growing stages. cDNAs for putative photoreceptors were cloned from this fungus. Three
genes named pcmada1, pcmada2, and pcmada3 were identified from the PCR fragments, and amplified with degenerated primers for the LOV domain, which is conserved in
many blue-light receptors. Deduced amino acid sequences for PCMADA1, PCMADA2, and PCMADA3 had one light-oxygen-voltage (LOV)-sensing
and two PER-ARNT-SIM (PAS) domains. A zinc finger DNA-binding motif was conserved in the C-terminals of PCMADA1 and PCMADA3.
However, PCMADA2 lacked the zinc finger motif. Expression of pcmada1 was suppressed by blue light whereas that of pcmada3 was promoted by blue-light irradiation. 相似文献