Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Two Novel Diterpenoids from Pygmaeopremna herbacea (1989)
    s.l. : American Chemical Society
    Journal of natural products 52 (1989), S. 581-587 
    Details
    ISSN: 1520-6025
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/np50063a018
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Protection of Amines by the Pyridine-2-sulfonyl Group and Its Cleavage under Mild Conditions (SmI2 or Electrolysis) (1995)
    s.l. : American Chemical Society
    The @journal of organic chemistry 60 (1995), S. 5969-5972 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo00123a041
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Degradation of the polyamine alkaloid aphelandrine by endophytic fungi isolated from Aphelandra tetragona (1997)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 155 (1997), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Members of the genus Aphelandra (Acanthaceae) produce rare macrocyclic polyamine alkaloids which consist of spermine acylated with two units of 3-(4-hydroxyphenyl)prop-2-enoic acid. Endophytic fungi were isolated from roots and shoots of Aphelandra tetragona and tested for their ability to metabolize the main alkaloid aphelandrine, which accumulates exclusively in the roots of the plants. Several endophytes were able to metabolize aphelandrine but only root endophytes belonging to the Nectriaceae were good metabolizers. In addition, the endophytes were grown on an agar medium containing putrescine, spermidine, or spermine as the sole nitrogen source. All fungi were able to grow on putrescine, but only the good aphelandrine metabolizers grew well on spermidine or spermine. Acremonium sp. 15, one of the most active metabolizers, grew also on a medium containing aphelandrine as sole nitrogen source. A number of strains thought to be conspecific with Acremonium sp. 15 were also tested for their ability to metabolize aphelandrine. The ability of the endophytes to metabolize aphelandrine suggests an ecological adaptation of the symbionts to their host. The possibility of using the aphelandrine metabolism as a taxonomic character is briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1574-6968.1997.tb13871.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Photosynthetischer Elektronentransport der Alge Bumilleriopsis während der Zellentwicklung (1976)
    Springer
    Planta 132 (1976), S. 53-59 
    Details
    ISSN: 1432-2048
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The alga Bumilleriopsis filiformis Vischer (Xanthophyceae) was synchronized by light intensity combined with temperature changes. During the 48-h cell cycle there is a stage of low cellular photosynthetic activity in the 34th hour after start of the cycle and one of high activity between the 39th and 41th hour. These activities were compared with the p-benzoquinone mediated Hill reaction of non-homogenized cells and electron transport rates measured with carefully isolated chloroplast material. Ferricyanide and methylviologen reduction was tested with water as donor and photosystem I reactions with reduced dichloro-phenolindophenol and diaminodurene. The influence of superoxide dismutase and ascorbate was examined. The data show parallel changes in the activities of electron transport and cellular photosynthesis during cell development and indicate corresponding alteration not only in the activity of photosystem II but also in that of system I.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00390330
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Wachstum und Synchronisierung der Alge Bumilleriopsis filiformis vischer (Xanthophyceae) (1974)
    Springer
    Planta 120 (1974), S. 135-146 
    Details
    ISSN: 1432-2048
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. Axenic cultures of Bumilleriopsis were cultivated in mineral medium under continuous illumination and diluted every two days. The growth has been calculated to be 0.50 log10/day units at the optimum temperature of 23 to 24° C. 2. In liquid medium one cell normally divides into 2n daughter cells (=aplanospores). Under our culture conditions generally 8 and 16 daughter cells are produced by one Bumilleriopsis cell within 48 h. 3. Bumilleriopsis filiformis is the first Xanthophycean species to be synchronized. Light-dark changes induce some synchronization, but a high percentage of simultaneous division and rapid completion of a cell division burst is brought about most effectively by cycles composed of strong light/dim light/temperature changes (LS-T). With the most effective combination tested, i.e. 33 h of white 15000 lux light followed by 15 h of white 3000 lux (dim) light at temperatures of 24° in the first and 19° C in the second light phase (=33:15 h/15000:3000 lux/24:19° C), 96% of the cells divide synchronously. The burst occurs in such a manner that, on an average, 50% of the cells have divided 38 h after the start of the cycle. These synchronizing conditions were maintained up to 30 cycles without interruption (=continuous synchronization). 4. Cell wall formation is observed (by staining mother cells with methylene blue) 1 to 2 h before the cells divide completely and their daughter cells are released.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00384923
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Characterization of synchronized cultures of Bumilleriopsis filiformis (1977)
    Springer
    Archives of microbiology 112 (1977), S. 141-145 
    Details
    ISSN: 1432-072X
    Keywords: Cell cycle ; Photosynthetic activity ; Electron transport of photosystems ; Fluorescence ; Cytochrome-f photooxidation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Activity of the photosynthetic apparatus of synchronized cultures was studied with the xanthophycean alga Bumilleriopsis filiformis, following the kinetics of fluorescence induction and photooxidation of cytochrome f (= cytochrome c-553) of intact cells. During the beginning of the cell-division phase, minimum cellular photosynthetic activity is observed and a maximum after its completion, which is accompanied by corresponding changes in Hill reaction activity and re-reduction of cytochrome f by photosystem II light. At minimum activity, the level of steady state fluorescence was higher than at the maximum. This is due, at least in part, to the diminished electron flow between the two photosystems seemingly caused by decreased photosystem I activity. This explanation was suported by the kinetics of cytochrome-f photooxidation. Thus, electron transport activity of both photosystems appears to vary during the cell cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00429326
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Characterization of queen-specific components of the fluid released by fighting honey bee queens (1999)
    Springer
    Chemoecology 9 (1999), S. 161-167 
    Details
    ISSN: 1423-0445
    Keywords: Key words: conflict; fighting behaviour; pheromone; gas chromatography; ortho-aminoacetophenone; insects; Hymenoptera; Apis; honeybee.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary. Swarming honey bee (Apis mellifera L.) colonies rear supernumerary young queens that compete for the limited resources (workers) necessary for founding a new colony. Young queens often fight to death. During fights, queens often release rectal fluid with a strong smell of grapes, after which they temporarily stop fighting. This potentially reduces the risk of deadly injury. The fluid and one of its components, ortho-aminoacetophenone, were previously found to have a pheromonal effect on workers. Recently, it has been suggested that the effects of this substance may be context- or concentration-specific. We performed semi-quantitative gas-chromatography mass spectrometry (GC/MS) analysis of the fluid (i) released by queens during their first fight, (ii) released during a subsequent fight, and (iii) obtained by dissecting the hindgut of queens and (iv) of workers. Following preliminary results by (Experientia 44:270–271), we scored presence/absence of eight substances. Five substances (ortho-aminoacetophenone, decanoic acid, dodecanoic acid, octyl decanoate, and decyl decanoate) were characteristic of queens only. ortho-Aminoacetophenone was detected in all queens and in none of the workers, in agreement with previous findings that worker rectal contents do not have pheromonal effect. The fluid released by queens on their second fight also contained ortho-aminoacetophenone, but in smaller quantities. This study confirms the unique presence in queens of five compounds, demonstrates their rectal origin, and estimates the amount of ortho-aminoacetophenone released during fights, as required to design experiments addressing the function and adaptive significance of fluid release behaviour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000490050049
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Chemical potential of Aphelandra sp. cell cultures (1999)
    Springer
    Plant cell, tissue and organ culture 58 (1999), S. 133-140 
    Details
    ISSN: 1573-5044
    Keywords: callus culture ; ESI-MS ; HPLC ; polyamines ; secondary metabolites ; verbascoside
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Six different callus lines and three different suspension culture lines were established from plants of two Aphelandra species (Acanthaceae). All established lines were analyzed for secondary metabolite accumulation. A discrepancy between secondary metabolites accumulated in the plants and in the cell cultures could be observed. All established Aphelandrasp. cell cultures produced verbascoside (acteoside) as the major extractable metabolite. Time course experiments were carried out to investigate the relationship between cell growth and verbascoside production. In the present study it was shown that verbascoside accumulation was growth dependent and positively related to the presence of 2,4-D in the medium. The conditions in which verbascoside represents ca. 18% of cell culture weight have been defined. Free polyamines were detected in the cell culture lines cultivated in MS liquid medium (cysteine 10 mg l-1, thiamine 1 mg l-1, 2,4-D 1 mg l-1, kinetin 0.2 mg l-1 and sucrose 30 g l-1). Putrescine and spermidine accumulated within 8 days to a maximum of 8.4 μmol g-1 of dry wt and 2.6 μmol g-1 of dry wt respectively and thereafter their concentration decreased rapidly. There was no evidence for the presence of spermine or any other type of free or conjugated polyamines in the tested cell culture lines.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006363612428
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Absolute configuration of macrocyclic spermidine alkaloids (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Chirality 9 (1997), S. 523-528 
    Details
    ISSN: 0899-0042
    Keywords: macrocyclic spermidine alkaloids ; stereoselective synthesis ; absolute configuration ; biogenesis ; stereochemistry ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this short review of several macrocyclic spermidine alkaloids, special consideration has been given to the correct determination of the absolute configuration at their chiral centers. The bases of interest are characterized by possessing a 13-membered macrocyclic lactam ring incorporating spermidine and either cinnammic or fatty acid precursorial units. In this context, the synthesis of some of these alkaloids is presented and the first total synthesis of optically pure (+)-(S)-viburnine, and (-)-(S)-celafurine is reported. Finally, a common initial step in biosynthesis starting with an enzyme-catalyzed Michael addition of spermidine to an α,β-unsaturated acid is proposed. Chirality 9:523-528, 1997. © 1997 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 10
    Electronic Resource
    Electronic Resource
    The systematic position of theHolarrheninae (Apocynaceae) (1990)
    Springer
    Plant systematics and evolution 171 (1990), S. 157-185 
    Details
    ISSN: 1615-6110
    Keywords: Angiosperms ; Apocynaceae ; Plumerioideae ; Apocynoideae ; Holarrheninae ; Holarrhena ; Carruthersia ; Spirolobium ; Floral structure ; pollen morphology ; indole alkaloids ; steroidal alkaloids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The genusHolarrhena, described byRobert Brown in 1811, has had a problematic taxonomic history, in part due to a suite of characters that does not conform with accepted concepts within theApocynaceae. In a number of important taxonomic charactersHolarrhena is typical of subfam.Apocynoideae. But due to the relatively unspecialized structure of the anthers most recent authors have placedHolarrheng, together withCarruthersia andSpirolobium, as the subtribeHolarrheninae in subfam.Plumerioideae. For the present investigation the floral structure and pollen morphology ofHolarrhena, Carruthersia andSpirolobium were analyzed. From the chemical literature reports of the occurrence of steroidal alkaloids in thePlumerioideae were evaluated. Our results indicate that the three genera belong to subfam.Apocynoideae in the tribeNerieae, but that the “Holarrheninae” is an unnatural group, and that the three genera should be accommodated individually within the tribe.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00940603
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...