Sakkadelic wrote:thank you endlessness
these numbers are so low, making the 0.16% seem dangerous, the numbers on that wiki article do not seem right though bcz we get 6% alkaloids from rue
I attached the article wikipedia references. They macerated the seeds in methanol 4x at 50 C. After that they did their own cleanup. It looks like they did not
squeeze the seeds, so they probably did not get all the alkaloids out
"attached paper" wrote:Four grams of dried and powdered seeds of P. harmala seeds were macerated four times with 50 mL methanol at 50◦C in a water bath for 1 h. After com-bination of the extracts, they were evaporated to dryness
They checked their spectral measurement vs. some standards to validate their spectrometer readings. However, the key phrase in the paper is:
"attached paper" wrote:the method could predict the concentration of the alkaloids in the seed’s extract correctly
So they are reporting on the alkaloids in the
extract, not in the
seeds (per their own words). In general, this is the typical way of reporting results, because how can you tell how well the extraction and cleanup went? That's very difficult, I think. That is why sometimes (I think), depending on the extraction process, some papers find no harmalol while others see some. Then at the end, when comparing their results to previous papers, they give the usual disclaimer that seeds are variable. While that is true, why not
also say that the extraction efficiency is another variable?
IDK, maybe I'm missing something.
But there is more. Wikipedia seems to have the numbers wrong. From the paper wikipedia references:
"attached paper" wrote:1.84%, 0.16%,
0.25% and 3.90% for harmine, harmane, harmalol and harma-
line, respectively.
Yet wikipedia got two of these wrong when referencing the paper: harmalol and harmaline are flipped in wikipedia! The attached paper is reference [32]
wikipedia wrote: Harmane, 0.16%[32]
Harmine, 0.44%[33]–1.84%[32]–4.3%[34]
The coatings of the seeds are said to contain large amounts of harmine.[7]
Harmaline, 0.25%[32]–0.79%[33]–5.6%[34]
Harmalol, 0.6%[34]–3.90%[32]
Tetrahydroharmine, 0.1%[34]
Total harmala alkaloids were at least 5.9% of dried weight, in one study.[32]
Vasicine (peganine),[16] 0.25%[33]
Vasicinone,[16] 0.0007%[33]
Oh, and sorry but there is more. The paper contradicts itself and in the conclusion gives 0.18% for Harmane instead of 0.16% like it does in the main body
Am I missing something???
"attached paper" wrote:the seed extracts of P. harmala showed that harmaline was the major alkaloid (3.90%) and its content was higher than that of the others (harmine, 1.84%; harmalol, 0.25% and harmane, 0.18%).
Moral of the story is that these extract papers seem to report on the measured
plant extract, not the
plant itself. There is an important factor between the two since alkaloids are lost during the extraction process.
Then, when papers disagree they typically bring up the "plants are variable" comment, and rarely say something like "we are really reporting on the measured extract, we don't know how efficient the extract itself was, so this is another source of variability".
Thing is, to shed more light on extract efficiency, the scientist could keep the extracts separate and trend the amount of alkaloids in each one (e.g. if the macerate a 5th time do they get 0?). But no, they don't typically do this. They have all this fancy extract analysis stuff, but why not focus on the plant material moar? Seems like they are more interested in the reducible analysis techniques once they get to a cleaned up extract rather than the amazing complex and rich plant they started with.
Credit to VDS for grinding the seeds after several extracts and keeping each one separate in his published work (but he was not doing this reductionist/math/spectral stuff). Why can't we get both?
Sorry for all the complaining. It's just that a lot of papers suffer from this issue. They get fancy analyzing the extract and forget about the plant. Then, when they have different results from other papers out comes the "plants are variable" verbiage. Well, what about doing more work on the efficiency of the extraction and cleanup steps??? Or at least mention that explicitly as a source of variation when trying to compare results.