Author Topic: Stinky Links  (Read 3660 times)

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biotechdude

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Master_Alchemist

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my god
« Reply #1 on: February 06, 2004, 10:40:00 AM »
Well i'll be damned, i am so goddamn tired after reading that.
to make it worse i started reading the next page to discover in horror 10 lines later, that page 2 is CC of page 1.
Aurielis, your post has got the better of me tonight!
goodnight all i think im about to haemorage.

Rhodium

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Analysis of Ephedrine Analogues from Ephedra
« Reply #2 on: April 08, 2004, 08:54:00 AM »
Quantitative Analysis of Ephedrine Analogues from Ephedra Species Using 1H-NMR
Hye Kyong Kim, Young Hae Choi, Wen-Te Chang and Robert Verpoorte

Chemical and Pharmaceutical Bulletin 51(12), 1382-1385 (2003)

(http://www.jstage.jst.go.jp/article/cpb/51/12/1382/_pdf)
DOI:

10.1248/cpb.51.1382



Abstract
Four ephedrine analogues such as ephedrine, pseudoephedrine, methylephedrine, and methylpseudoephedrine were determined by 1H-NMR from Ephedra species. In the region of ? 5.0—4.0, the signals of H-1 attached to the same carbon with a hydroxyl, were well separated from each other in CDCl3H. The amount of each alkaloid was calculated by the relative ratio of the intensity of H-1 signal to the known amount of internal standard, 200 ?g of anthracene. This method allows rapid determination of the quantity of four ephedrine alkaloids from Ephedra species. The amount of these alkaloids was in the range of 1.0—2.0% of dry weight depending on the plant materials.


mellow

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Don't forget E. equisetina
« Reply #3 on: April 08, 2004, 09:48:00 AM »
biotechdude

Don't forget E. equisetina - an excellent plant which grows in temperate climes, resists frost well and produces proflific amounts of ephedrine.

obelisk

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ephedra
« Reply #4 on: April 11, 2004, 10:37:00 AM »
I have done the work on three positively identified north american species and there is not one trace of usable alkaloid present.
  These species centered around northern nevada.

Rhodium

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Ephedra Alkaloid Content in Dietary Supplements
« Reply #5 on: September 13, 2004, 03:54:00 PM »
Concentrations of Ephedra Alkaloids and Caffeine in Commercial Dietary Supplements
Haller C.A.; Duan M.; Benowitz N.L.; Jacob III P.
Journal of Analytical Toxicology 28(3), 145-151 (2004)
 
Abstract
Dietary supplements that contain Ma Huang (ephedra alkaloids) and guarana (caffeine) are widely marketed and used in the U.S. for weight loss and athletic performance enhancement, despite a lack of adequate research on the pharmacology of these botanical stimulants. We developed and applied a novel liquid chromatography–tandem mass spectrometry (LC–MS–MS) method to quantitate the various ephedra alkaloids found in dietary supplements that contain Ephedra species. The quantities of ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedine, methylpseudoephedrine, and caffeine were determined for 35 commercial dietary supplements and compared with the amounts listed on the product labels. The total ephedra alkaloid content ranged from 5.97 mg to 29.3 mg per serving. Two supplement brands did not list the quantity of ephedra alkaloids on the label, and four did not list the amount of caffeine per serving. Of the products tested, 31% contained > 110% of the total ephedra alkaloids listed on the label, and 6% of the supplements contained < 90% of the listed amount. For caffeine, 86% of the product lots that listed the caffeine amount contained less than 90% of the labeled quantity. No products contained > 110% of the declared caffeine content. The total ephedra alkaloid content varied significantly from lot to lot in 5 of 9 products. Three product brands contained proportions of alkaloids that exceeded amounts reported for E. sinica, including one that was 98% ephedrine, one that had 10% norpseudoephedrine, and one that contained an average of 13% methylephedrine. We conclude that product inconsistency is common among some commercially available dietary supplements that contain ephedra alkaloids and caffeine.


Rhodium

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Determination of Ephedra Alkaloids
« Reply #6 on: October 11, 2004, 11:44:00 AM »
Determination of Ephedra Alkaloids by Liquid Chromatography/Tandem Mass Spectrometry
Darryl Sullivan, James Wehrmann, John Schmitz, Richard Crowley, and Jeffrey Eberhard

Journal of AOAC International Vol. 86, No. 3, 471-475 (2003)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/ephedra.analysis.aoac-1.pdf)

Abstract
In conjunction with an AOAC Task Group on dietary supplements, a liquid chromatography/tandem mass spectrometry (LC–MS/MS) method was validated for measurement of 6 major alkaloids in raw ephedra sinica herb, ephedra extracts, ephedra tablets, complex dietary supplements containing ephedra, and a high-protein drink mix containing ephedra. The amount of ephedrine-type alkaloids present was determined by LC with mass selective detection. Six replicates of each matrix were analyzed on 3 separate occasions. The presence of 6 ephedrine-type alkaloids was detected at a level >0.5 µg/g based on a 0.5 g sample. The standard curve range for this assay is from 0.02 to 1.0 µg/mL. Appropriate dilutions covered a wide range of specific alkaloid concentrations. The calibration curves for all 6 analytes had correlation coefficients >0.995.
____ ___ __ _

Determination of Ephedrine Alkaloids in Dietary Supplements and Botanicals by Liquid Chromatography/Tandem Mass Spectrometry: Collaborative Study
William A. Trujillo and Wendy R. Sorenson

Journal of AOAC International Vol. 86, No. 4, 657-668 (2003)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/ephedra.analysis.aoac-2.pdf)

Abstract
An interlaboratory study was conducted to evaluate the accuracy and precision of a method for ephedrine-type alkaloids [i.e., norephedrine (NE), norpseudoephedrine (NPE), ephedrine (E), pseudoephedrine (PE), methylephedrine (ME), and methylpseudoephedrine (MPE)] in dietary supplements and botanicals. The amount of ephedrine-type alkaloids present was determined using liquid chromatography with tandem mass selective detection. The samples were diluted to reflect a concentration of 0.0200 to 1.00 µg/mL for each alkaloid. An internal standard was added and the alkaloids were separated using a 5 µm phenyl LC column with an ammonium acetate, glacial acetic acid, acetonitrile, and water mobile phase. Eight blind duplicates of dietary supplements or botanicals were analyzed by 10 collaborators. Included was a negative control, ephedra nevadensis, and negative controls fortified at 2 different levels with each of the 6 ephedrine-type alkaloids. The spike levels were approximately 100 and 1000 µg/g for NE, 100 and 600 µg/g for NPE, 6500 and 65 000 µg/g for E, 1000 and 10 000 µg/g for PE, 300 and 3000 µg/g for ME, and 100 and 1000 µg/g for MPE. On the basis of the accuracy and precision results for this interlaboratory study, it is recommended that this method be adopted Official First Action for the determination of 6 different individual ephedrine-type alkaloids in dietary supplements and botanicals.


Xaja

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Biotechdudes post
« Reply #7 on: November 02, 2004, 05:45:00 PM »
Nice idea. Would be interesting to know how many genes are involved in the process. Hopefully only a few, and not many genes located on different chromosomes, which would make things difficult!

But yeah, BAC inserts via Agrobacterium tumefaciens can now deliver QTLs or multigene families directly into the plant genome, so its not out of the question, providing you can get access to a decent lab that uses the technology.

Expression in bacteria would be too complicated in my view. Well, still possible but a lot of work creating the vector, then introducing the genes then selecting for transformants. Also the gene products could be toxic to the bacteria or insoluble in their cytoplasm etc etc.

Although having the eph produced in a bacterial system would be a dream come true. Imagine how fast it would be!!!  8)


Xaja

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Reference
« Reply #8 on: November 02, 2004, 05:49:00 PM »
Just for the sake of good science, here's a reference that shows the direct plant transformation by Agobacterium with BAC inserts:

http://www.siu.edu/~pbgc/publications/6.pdf