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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.
L. Wanntorp H.-E. Wanntorp B. Oxelman M. Källersjö 《Plant Systematics and Evolution》2001,226(1-2):85-107
The phylogeny of the genus Gunnera is investigated for the first time. Twelve species representing the six currently recognised subgenera are analysed. Two
chloroplast DNA regions, the rbcL gene and the rps16 intron, together provide 46 informative characters out of 2335. A combined analysis of both genes gives four most parsimonious
trees, firmly establishing the east South American G. herteri as sister group to the rest of the genus. The African G. perpensa is sister group to two well-supported clades, one including the South American subgenera Misandra and Panke, the other the Australian/New Zealand/Malayan species of subgenera Milligania and Pseudogunnera. Thus, South America is a composite area for Gunnera, showing up at two different levels in the cladogram. Our analysis supports a close biogeographic relationship between Australia
and New Zealand. The evolution of some morphological characters is discussed. Lastly, the unusual structure of some of the
rbcL sequences is reported.
Received July 6, 2000 Accepted October 24, 2000 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.
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
6.
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
7.
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
8.
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
9.
In this paper comparative histological studies of embryo-like structures originating from callus cultures, and zygotic embryos
originating from sexual seeds of Cuscuta trifolii are reported. The embryos of somatic cell and zygote origin showed similar morphological and anatomical features, such as
a complete lack of cotyledon development and the differentiation of a developmentally unique root primordium specialised for
water storage. Based on these findings, the regeneration of C. trifolii from callus cultures is shown to proceed along the pathway of somatic embryogenesis.
Received: 9 November 1998 / Revision received: 22 April 1999 / Accepted: 29 June 1999 相似文献
10.
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
11.
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
12.
Isolated populations are particularly prone to extinction, and understanding their temporal dynamics is relevant for conservation
and management. In this study, the abundance of a population of the nocturnal leaf-toed gecko Euleptes europaea was estimated by mark-recapture over a 12-year period in northwest Italy. Simulation tests showed the presence of density-dependence,
and autoregressive analyses indicated that direct density dependence was responsible for a large part of the variation in
population growth rates. Density-dependent recruitment was suggested as the main demographic mechanism controlling population
dynamics, which was also affected by solar radiation measured during the active gecko season. These results may contribute
to implement conservation strategies in other small and isolated leaf-toed gecko populations. 相似文献
13.
Peptide fragments that exhibit antimicrobial activity in vitro have been shown to be produced by cleavage from the hydrophilic
region near the N terminus of various vicilin proteins in plant seeds. Three peptide sequences identified in the hydrophilic
region of vicilin seed proteins of Macadamia integrifolia and Theobroma cacao were predicted to exhibit antimicrobial activity based on sequence similarity to antimicrobial peptides that had been previously
purified from macadamia kernels. Histidine-tagged versions of the putative antimicrobial peptides were expressed in Escherichia coli, purified, and demonstrated to have in vitro antimicrobial activity. There are many vicilin sequences in the growing plant
genome sequence databases, and this expression method provides a high-throughput process for functionally testing the potential
of internal peptide fragments of vicilins as novel antimicrobial molecules. 相似文献
14.
Bourguyia hamata females oviposit almost exclusively inside the rosette formed by the curled leaves of the epiphytic bromeliad Aechmea nudicaulis. We investigated whether the architecture of the individual bromeliads influences oviposition site selection by this harvestman
species. We collected data on the presence of clutches inside bromeliads, rosette length, rosette slope in relation to tree
trunks, and the amount of debris inside the rosette. Additionally, we measured the water volume inside the rosettes as well
as the variation in the humidity inside and outside bromeliads with long and short rosettes. Longer rosettes were preferred
as oviposition site possibly because they accumulate more water and maintain lower internal humidity variation than the external
environment. Although the slope of the rosettes did not influence the occurrence of oviposition, the probability of debris
accumulation inside the rosettes increased with their slope, and the frequency of clutches was greater in bromeliads with
small amounts of debris. A field experiment showed that bromeliads with water inside the rosette were more frequently used
as oviposition sites than bromeliads without water. In conclusion, females oviposit predominantly in bromeliads that accumulate
more water and have small amounts of debris inside the rosettes, probably because these characteristics promote a more adequate
microhabitat for egg development. 相似文献
15.
16.
Dmitar Lakušić 《Biologia》2008,63(5):631-636
The south-European Cardamine plumieri Vill. (sect. Pteroneurum subsect. Cryptopterum) is confirmed for the Flora of Serbia. Several populations were discovered in the central and western part of country, exclusively
on the serpentine bedrocks. Morphological, chorological and ecological characteristics of C. plumieri was studied. 相似文献
17.
The wolf spider Pardosa cribata Simon is the most abundant ground-dwelling spider inhabiting citrus orchards in eastern Spain. However, little is known about
its activity-density and its predatory role in the citrus agrosystem. Here we report on the activity-density of P. cribata monitored by pitfall traps, and on its capacity to prey on two citrus pests that appear both in the citrus canopy and the
ground cover, Ceratitis capitata (Wiedemman) and Myzus persicae (Sulzer), respectively. Pardosa cribata was present in citrus orchards throughout the year, with a peak in spring and a higher peak in summer. Pardosa cribata preyed on adults and third-instar larvae but not on pupae of C. capitata. A type II functional response was obtained for teneral-like adults, with an estimated attack rate (a′) of 0.771 ± 0.213 days−1 and a handling time (T
h) of 0.051 ± 0.013 days. Pardosa cribata also preyed efficiently on M. persicae, giving a type II functional response with an estimated attack rate and handling time of 2.833 ± 0.578 days−1 and 0.031 ± 0.001 days, respectively. The data reported here indicate that this wolf spider could play an important role
in regulating both these pests, and therefore might contribute to developing conservation biological control strategies for
citrus pests.
Handling Editor: Arne Jenssen. 相似文献
18.
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
19.
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