Forbeside E: a novel sulfated sterol glycoside from Asteriasforbesi

1989 ◽  
Vol 67 (12) ◽  
pp. 2078-2080 ◽  
Author(s):  
John A. Findlay ◽  
Zheng-Quan He ◽  
Mahesh Jaseja
Keyword(s):  
Natural Product ◽  
Disodium Salt ◽  
Minor Constituent ◽  
Sterol Glycoside ◽  
Saponin Fraction ◽  
A Minor

The structure of forbeside E, a minor constituent of the saponin fraction of the starfish Asteriasforbesi, has been identified as the disodium salt of (20R)-5α-pregn-9(11)ene-3β-sulfo-oxy-6α-[O-β-D-4-sulfo-oxyquinovopyranosyl]-20-ol, principally by 2D-COSY, DQ COSY, HCORR, and DEPT experiments. Sodium thornasterol-3-O-sulfate has been isolated as a natural product from the same organism. Keywords: sulfated sterol glycoside, Asteriasforbesi metabolites, sodium thomasterol-3-O-sulfate, asterogenol rearrangement.

Heterogeneous Formation of Oriented Silicon Oxynitride on α-Si3N4 Seed Crystals : Habits And Radiation Stability

1999 ◽  
Vol 5 (S2) ◽  
pp. 778-779
Author(s):  
R.W Carpenter ◽  
W Braue ◽  
M.J. Kim
Keyword(s):  
Silicon Nitride ◽  
Heterogeneous Nucleation ◽  
Radiation Stability ◽  
Silicon Oxynitride ◽  
Minor Constituent ◽  
Sintering Aids ◽  
Sintering Aid ◽  
Nucleation Sites ◽  
Heterogeneous Formation ◽  
A Minor

Lath-like silicon oxynitride crystals have often been observed in the microstructure of silicon nitride based ceramics after processing. They are usually located in glassy regions which are siliceous solidified sintering aid liquid, and usually contain a small (∼100nm) a-Si3N4 crystal. These nitride crystals are considered to be seeds, incompletely dissolved in the melt, that are heterogeneous nucleation sites for the oxynitride crystals. We present here the first observations of morphological and crystallographic habits between the seed nanocrystals and the host oxynitride laths.Fig. 1 shows a typical oxynitride lath containing a nitride seed crystal. The lath is surrounded by glass and ß-Si3N4 particles, and a small cristobalite particle (a minor constituent). This microstructure is from an Si02-Si3N4 ceramic processed with Al2O3 sintering aid. The same oxynitride lath/seed structures were observed when other sintering aids (eg. Y2O3, MgO, ZrO2) were used, so they are independent of sintering aid.

scholarly journals Betaine Yields from Marine Algal Species Utilized in the Preparation of Seaweed Extracts Used in Agriculture

2010 ◽  
Vol 5 (4) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Gerald Blunden ◽  
Peter F. Morse ◽  
Imre Mathe ◽  
Judit Hohmann ◽  
Alan T. Critchley ◽  
...  
Keyword(s):  
Marine Algae ◽  
Algal Species ◽  
First Record ◽  
Commercial Production ◽  
The Other ◽  
Minor Constituent ◽  
Laminaria Digitata ◽  
Seaweed Extracts ◽  
Marine Algal ◽  
A Minor

Ascophyllum nodosum, and to a lesser extent, Laminaria digitata, L. hyperborea and Fucus serratus, are marine algal species utilized in the commercial production of seaweed extracts used in agriculture. Betaines have been shown to be important constituents of these extracts, but there appears to have been no study made on whether there are variations in the betaine contents of these species based on either the place or date of collection. Samples of each of the four species were collected from widely separated areas at different times of the year. Also, in the case of A. nodosum, approximately monthly collections were made from one location. The betaines detected in the various collections of the same species showed little variation, although in the case of A. nodosum, glycinebetaine was found as a minor constituent in some samples, but was not detected in others. Trigonelline was found in all the tested samples of the two Laminaria species; this is, to our knowledge, the first record of this betaine in marine algae. With the exception of trigonelline in the Laminaria species, the betaine yields from the various samples of L. digitata, L. hyperborea and F. serratus showed little variation, regardless of either the place or date of collection. The trigonelline contents of the Laminaria species collected at one location (Finavarra, Ireland), in particular of L. hyperborea, was substantially greater than those from the other places of collection. In the case of A. nodosum, the betaine yields from samples collected at one site (Dale, Pembrokeshire, UK) were significantly higher than those from the other places of collection, which were very similar to each other. There was no clear indication of seasonal variation in betaine yields from A. nodosum.

scholarly journals MOMILACTONE-C, A MINOR CONSTITUENT OF GROWTH INHIBITORS IN RICE HUSK

1976 ◽  
Vol 5 (11) ◽  
pp. 1157-1158 ◽  
Author(s):  
Mitsuaki Tsunakawa ◽  
Akihiro Ohba ◽  
Nobuki Sasaki ◽  
Chizuko Kabuto ◽  
Tadahiro Kato ◽  
...  
Keyword(s):  
Rice Husk ◽  
Growth Inhibitors ◽  
Minor Constituent ◽  
A Minor

Synthesis of ginsenoside Rg3, a minor constituent of Ginseng Radix

1997 ◽  
Vol 304 (2) ◽  
pp. 179-182 ◽  
Author(s):  
Victor Ph. Anufriev ◽  
Galina V. Malinovskaya ◽  
Vladimir A. Denisenko ◽  
Nina I. Uvarova ◽  
Georgi B. Elyakov ◽  
...  
Keyword(s):  
Minor Constituent ◽  
Ginsenoside Rg3 ◽  
A Minor

scholarly journals Base J originally found in Kinetoplastida is also a minor constituent of nuclear DNA of Euglena gracilis

2000 ◽  
Vol 28 (16) ◽  
pp. 3017-3021 ◽  
Author(s):  
D. Dooijes
Keyword(s):  
Euglena Gracilis ◽  
Nuclear Dna ◽  
Minor Constituent ◽  
A Minor

scholarly journals Quinolizidine Alkaloid Profiles of Two Taxa of Teline maderensis

2003 ◽  
Vol 58 (11-12) ◽  
pp. 776-778 ◽  
Author(s):  
Alice Martins ◽  
Michael Wink ◽  
Andreas Tei ◽  
Amélia P. Rauter
Keyword(s):  
The Other ◽  
Minor Constituent ◽  
Alkaloid Composition ◽  
Quinolizidine Alkaloid ◽  
Aerial Parts ◽  
Capillary Glc ◽  
A Minor ◽  
Alkaloid Profiles

Abstract The alkaloid composition of the aerial parts of two taxa of Teline maderensis was studied by capillary GLC and GLC-MS. N-Methylcytisine was the major alkaloid found in both plants. Contents of cytisine and lupanine were higher in T. maderensis var. paivae while anagyrine content was more pronounced in T. maderensis var. maderensis. The alkaloids dehydrocytisine, N-acetylcytisine and epibaptifoline appeared only in T. maderensis var. maderensis and N-formylcytisine was identified as a minor constituent in T. maderensis var. paivae, and detected only in trace amounts in the other variety of the plant.

Mineralogical Problems in X-Ray Emission Analysis of Sylvite Concentrates

1963 ◽  
Vol 7 ◽  
pp. 555-565
Author(s):  
Frank Bernstein
Keyword(s):  
Particle Size ◽  
Atomic Number ◽  
Size Effects ◽  
Quantitative Relationship ◽  
Minor Constituent ◽  
Emission Analysis ◽  
X Ray ◽  
Particle Size Effects ◽  
Chemical Combination ◽  
A Minor

AbstractMineralogical effects, which relate to the occurrence of an element in different forms of chemical combination, often are a problem to the X-ray analyst since these forms usually differ in X-ray sensitivity. An example of this is cited in connection with the analysis of sylvite concentrates for potassium. An evaluation is made of mineralogical effects and a quantitative relationship between X-ray intensity and mineral form and particle size is derived. If the particle size of a minor constituent is reduced sufficiently the mineralogical effect disappears. Target materials for X-ray sources are found to have only minor effects on relative intensities of different compounds of an element. Finally, it is concluded that the advantages of higher intensities gained through the use of target materials close in atomic number to the material being analyzed far outweigh particle size effects which are shown to be relatively small.

Skeletal composition of modern lagoon sediments in New Caledonia: coral, a minor constituent

Coral Reefs ◽  
1996 ◽  
Vol 15 (3) ◽  
pp. 199-207
Author(s):  
C. Chevillon
Keyword(s):  
New Caledonia ◽  
Minor Constituent ◽  
Lagoon Sediments ◽  
A Minor

Vanadian allanite-(La) and Vanadian allanite-(Ce) from the Hemlo gold deposit, Ontario, Canada

1991 ◽  
Vol 55 (381) ◽  
pp. 497-507 ◽  
Author(s):  
Yuanming Pan ◽  
Michael E. Fleet
Keyword(s):  
Solid State ◽  
Gold Deposit ◽  
Hydrothermal Alteration ◽  
Direct Contact ◽  
Close Association ◽  
Octahedral Coordination ◽  
Local Source ◽  
Minor Constituent ◽  
Simple Substitution ◽  
A Minor

AbstractAllanite-(La) (containing up to 7.80 wt.% V2O3 and with La/ΣREE and La/Ce atomic ratios up to 0.54 and 1.45, respectively) and allanite-(Ce) (up to 8.46 wt.% V2O3) occur in close association with vanadian muscovite, barian tomichite and vanadian titanite in the main ore zone of the Hemlo gold deposit, Ontario, Canada. Allanite-(Ce) generally occurs as a minor constituent in cross-cutting veins or along foliation planes, whereas allanite-(La) invariably occurs in direct contact with titanite. The high V concentrations in the allanites from Hemlo are readily attributable to an adequate local source of this element, and are most likely controlled mainly by a simple substitution of V for Al in octahedral coordination. Vanadian allanite-(La) and vanadian allanite-(Ce), without any systematic differences in other constituents, are clearly distinct in REE composition, in respect to both the relative concentrations of La and Ce and abundances of other REE. The formation of both allanites (Ce- and La-rich) indicates very localised remobilisation and concentration of REE during a late hydrothermal alteration. The unusual REE composition of vanadian allanite-(La) directly reflects partitioning of REE with coexisting titanite, and the formation of this unusual phase may be attributable to replacement of earlier titanite with redistribution of REE in the solid state.

Extractives of Australian timbers. XVII. The isolation, structure and synthesis of koparin (7,2',3'-Trihydroxy-4'-methoxyisoflavone)

1977 ◽  
Vol 30 (8) ◽  
pp. 1827 ◽  
Author(s):  
RC Berry ◽  
RA Eade ◽  
JJH Simes
Keyword(s):  
Spectroscopic Methods ◽  
Minor Constituent ◽  
Castanospermum Australe ◽  
A Minor

The isolation of koparin, a minor constituent of the wood of Castanospermum australe, is described. By a combination of chemical and spectroscopic methods koparin was shown to be either 7,3?,4?-tri- hydroxy-2?-methoxyisoflavone (5) or 7,2?,3?-trihydroxy-4?- methoxyisoflavone (6). The latter compound has been synthesized by demethylenation of 7-hydroxy-4?-methoxy-2?,3?-methylenedioxyiso- flavone (9) and is identical with koparin.

Sign in / Sign up

Export Citation Format

Share Document