sonogashira
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German translation: Some help requested
I've been trying to work out what's going on here for several hours, but without success.
If someone who speaks German would be so kind as to help me out i would be most thankful. (I have added my attempt at a translation and the problems
I've had in working from that; though i think that I'm probably so far off that starting from scratch may be easier)
It concerns the extraction of a glucoside from a fungus:
"Eine Anzahl Pilze wurden mit einer Schere fein zerschnitten; ihr Gewicht war etwa 1,55g. Extraktion mit konzentriertem Spiritus gab einen
geringen, gelbbraunen Rückstand (etwa 0,16g) der sich zum grössten Teil in Aether löste und wahrscheinlich aus Fett bestand -- Die getrockneten
Drogenreste (1,39g) wurden mit dest. Wasser übergossen, eine Weile auf dem Wasserbade digeriert und nachher filtert. Das Filtrat war braun, klar,
mit schwachem Pilzgeruch und ohne deutlichen Geschmack. Reaktion auf Lackmus recht stark sauer. Die wässrige Lösung wurde auf den Rückstand der
abgedampften Alkohollösung gegossen, dieser zerrieben und ungelöste Flocken abfiltriert.
Die Bieuretreaktion fiel negativ aus, ebenso die meisten Alkaloidreactionen. Nur Phosphorwolframsäure gab einen starken gelbweissen
Niederschlag, Phosphormolybdänsäure rief nach Kochen eine graugrüne Fällung hervor. PtCl4, HgCl2, Pikrinsäure und Gerbsäure erzengten keinen
Niederschlag. Fehlings Probe einen schwach positiven Auschlag – einen recht bedeutenden, blassgelben (nicht roten) Bodensatz. Die Gegenwart eines
Glucosides ist wenigstens möglich.
Crude translation:
A number of mushrooms were cut finely with scissors; their weight was about 1.55g. Extraction with concentrated alcohol [1] gave
small, yellow-brown residue [2] (about 0.16g) to the largest part in ether separated and probably from fat existed -- the dried drug
remainders (1.39g) were with distilling.[3] Water poured over, one while on the water bath digests and filters afterwards.
[4] The filtrate was brown, clear, with weak mushroom smell and without clear taste. Reaction to litmus quite strongly acidic. The
aqueous solution was poured onto the residue of the evaporated alcohol solution, these were ground and unresolved flakes was filtered off.
The Biuret reaction failed negatively, likewise most Alkaloidreactionen. Only phosphorus tungsten acid gave a strong yellowish white precipitation,
and phosphorus molybdenum acid caused after heating a grey-green precipitation. PtCl4, HgCl2, Picric acid and Gerbsaure [5] did not
ore-confine a precipitation. Fehlings sample a weakly positive Ausschlag - a quite meaning, pale-yellow (not red) sediment. The presence of a
Glucosides is at least possible.
[1] Is this alcohol (ethanol) or white spirit?
[2] Has the ethanol been removed here? I guess by the weights involved that this is the ethanol-soluble portion.
[3] I'm really unsure about this.
a) Has the dried ethanol extract now been washed (de-fatted) with ether, or has the wanted product been extracted with ether.
b) Has ether been added to the ethanol solution precipitating the wanted product, then the solvents removed by distillation?
c) Has the plant material been extracted with ether? (I dont think it has but am not sure why the weight of the plant material is given here).
[4] A water extract of what?? The plant material, the ether extract, the ethanol extract??????
What is Phosphormolybdänsäure and Phosphorwolframsäure (and what are they used for if anyone knows?)
Not sure what Gerbsäure is. Tannic acid perhaps? What does Ausschlag mean?
If someone would be so kind, i would really appreciate it. That it's such a simple procedure just makes it all the more frustrating .
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SecretSquirrel
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| Quote: | | What is Phosphormolybdänsäure and Phosphorwolframsäure (and what are they used for if anyone knows?) |
Phosphormolybdänsäure - Phosphomolybdic acid
Use: As reagent for alkaloids, uric acid, xanthine, creatinine, some metals, with hematoxylin as nerve stain in microscopy.
Phosphorwolframsäure - Phosphotungstic acid
Use: As reagent for alkaloids and many other nitrogen bases, for phenols, albumin, peptone, amino acids, uric acid, urea, blood,
carbohydrates; as biological stain.
Source of the info: Merck index, 13th edition
(1) The solvent is ethanol.
(2) I think this is the residue left after removing the solvent (in this case EtOH). It mainly consisted from fats and was almost
completely soluble in ether.
(3) It think the dried mushroom material left after extraction is washed with distilled water, filtered and the filtrate was poured
on the evaporated EtOH residue.
Mind you, German is not my native language either so someone might correct if I translated some words incorrectly.
[Edited on 14-4-2007 by SecretSquirrel]
[Edited on 14-4-2007 by SecretSquirrel]
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sonogashira
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Thanks so much for your help. It certainly makes more sense now.
This sentence is still troubling me though:
“Extraktion mit konzentriertem Spiritus gab einen geringen, gelbbraunen Rückstand (etwa 0,16g) der sich zum grössten Teil in Aether löste
und wahrscheinlich aus Fett bestand -- Die getrockneten Drogenreste (1,39g) wurden mit dest. “
Surely any “fat” that may be present is soluble in ether? Is it just claiming that the ethanol extract is largely free of fat (seemingly without
proof), then this ethanol extract is further extracted with ether (where it almost fully dissolves), then filtered (though it doesn't mention this).
Or is this a de-fatting step?
And what about the reference to distilling (if that is the right translation)? Does this simply mean that the ethanol was removed with distilling, or
the ether was removed?
Thanks for looking up those two acids. It seems that they were as tests for alkaloids in this context.
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not_important
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Gerbsäure is purified tannic acid
http://www.drak.de/Glossar/Xtended/Tannin.html
Ausschlag can mean excusion, eruption, blotch - in this case a result, a colour change, a precipitate.
I need to pounder that troublesome sentence a bit.
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SecretSquirrel
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| Quote: | Originally posted by sonogashira
And what about the reference to distilling (if that is the right translation)? Does this simply mean that the ethanol was removed with distilling, or
the ether was removed? |
Do you mean this sentence: Die getrockneten Drogenreste (1,39g) wurden mit dest. Wasser übergossen, eine Weile auf dem Wasserbade digeriert und
nachher filtert.
If so, I think it is not a distillation as much as it is simple dissolution of things left in the dried mushroom material after alcohol extraction.
The thanslation is something like this:
The dried drug remainders (1,39g) were mixed with distilled water, heated on a waterbath and filtered.
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garage chemist
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“Extraktion mit konzentriertem Spiritus gab einen geringen, gelbbraunen Rückstand (etwa 0,16g) der sich zum grössten Teil in Aether löste und
wahrscheinlich aus Fett bestand -- Die getrockneten Drogenreste (1,39g) wurden mit dest. Wasser übergossen, eine Weile auf dem Wasserbade digeriert
und nachher filtert. Das Filtrat war braun, klar, mit schwachem Pilzgeruch und ohne deutlichen Geschmack. Reaktion auf Lackmus recht stark sauer. Die
wässrige Lösung wurde auf den Rückstand der abgedampften Alkohollösung gegossen, dieser zerrieben und ungelöste Flocken abfiltriert. “
Extraction with Spiritus (Ethanol) yielded a small yellow-brown residue (ca. 0,16g) which dissolved in ether nearly completely and probably consisted
of fat.
The dried residues of the drug (1,39g) were mixed with distilled water, stirred for a while on the water bath (probably means warming, its not clear)
and filtered. The filtrate was brown, clear, with weak mushroom odor and without appreciable taste. Quite strongly acidic to litmus.
This aqueous solution was poured upon the residue from the evaporated alcohol extraction, ground together, and filtered from undissolved material.
"Die Bieuretreaktion fiel negativ aus, ebenso die meisten Alkaloidreactionen. Nur Phosphorwolframsäure gab einen starken gelbweissen Niederschlag,
Phosphormolybdänsäure rief nach Kochen eine graugrüne Fällung hervor. PtCl4, HgCl2, Pikrinsäure und Gerbsäure erzengten keinen Niederschlag.
Fehlings Probe einen schwach positiven Auschlag – einen recht bedeutenden, blassgelben (nicht roten) Bodensatz. Die Gegenwart eines Glucosides ist
wenigstens möglich."
The biuret reaction was negative, and so were most tests for alkaloids. Only Phosphotungstic acid yielded a strong yellow-white precipitate,
phosphomolybdic acid yielded a grey-green precipitate upon boiling.
PtCl4, HgCl2, picric acid and tannic acid did not produce any precipitate. A test with Fehlings solution was weakly positive- an appreciable, pale
yellow (not red) precipitate.
The presence of a glucoside is at least possible.
In order to make it clear, there is no isolation of any sort carried out.
In the first part translated above, it is merely stated that extraction with ethanol yielded an ether-soluble residue (assumed to be fat). A second
extraction of the mushroom material, this time with water, yielded the aqueous solution, which was combined with the residue from the alcohol
extraction by grinding and filtering off any undissolved material.
(German is my first language)
[Edited on 15-4-2007 by garage chemist]
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sonogashira
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Thank you all so very much.  I can't tell you how much i appreciate the kind help.
Thanks garage chemist for going to all that trouble. Bless you all 
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