Talk:Β-Hydroxy β-methylbutyric acid/Archive 1

This is an archive of past discussions about Β-Hydroxy β-methylbutyric acid. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page.

Archive 1

Untitled

I removed the advertisement from the bottom of this page. Unless the author can cite references for what is said from "Performance Benifits" on it should be removed. Gravitate (talk) — Preceding unsigned comment added by Gravitate (talk • contribs) 21:47, 11 July 2006‎ (UTC)

I've removed the lot. All the other contribs by the same person were all similar spammings - MPF 21:28, 16 July 2006 (UTC)

Discovered by

I added this sentence because Dr. Steve Nissen originally discovered and patented it as a nutritional supplement and I thought that merited inclusion. I attempted to make it unbiased and if there is any slant please feel free to change the wording of it. Just make sure to include that he introduced it based on research that he did (at Iowa State University). Here's some links to verify that he did introduce it [1] [2] Quadzilla99 11:21, 31 August 2006 (UTC)

I believe he did not discover it as it was around in the 50s and 60s so perhaps the sentance should be revised. —Preceding unsigned comment added by 194.73.108.219 (talk) 15:44, 9 April 2009 (UTC)

Above links are now dead. I will remove reference to ‘discovery’. ☸ Moilleadóir ☎ 02:48, 28 January 2014 (UTC)

Melting point

Melting point cant be -80C... seems erronous. 123.50.129.156 (talk) 21:56, 27 February 2008 (UTC)

That is the value given at the link in the reference provided ... which in turn references the Beilstein database. Unless there is a contradictory value in another reference you can find, I don't think there is any reason to doubt it. -- Ed (Edgar181) 22:12, 27 February 2008 (UTC)

-80 sounds too low but I've seen a couple sources that say its a liquid at room temp. which is possible considering the intramolecular hydrogen bonding. —Preceding unsigned comment added by Pelirojopajaro (talk • contribs) 01:01, 8 January 2009 (UTC)

129 studies

I think this is misleading. The review has 129 REFERENCES, it doesn't go over 129 studies that dealt with HMB. I would say that less than 40 of them were actually original research on HMB. I don't want to go through and count them, but I think the 129 references is misleading. -Rjkd12 —Preceding unsigned comment added by 24.148.46.214 (talk) 18:09, 22 October 2008 (UTC)

SVG diagram of File:ISSN HMB statement Fig 1.jpg (Leucine metabolism in humans)

A .jpg diagram of leucine metabolism in humans (File:ISSN HMB statement Fig 1.jpg)

@Slashme: Hey, would you be interested in working with me to recreate File:ISSN HMB statement Fig 1.jpg as a wikitext-annotated SVG diagram for the en: and af: Wikis? I think you did a great job on the svg diagram for {{Tryptophan metabolism by human microbiota}}, so I figured I'd ask if you were interested in creating an svg version of this diagram (without image text). The jpg image file is also used on the ja: Wiki; so, if you're willing to create the blank SVG diagram, I could probably find someone that can read/write Japanese to re-annotate the image text for that Wiki as well. Seppi333 (Insert 2¢) 21:46, 27 November 2017 (UTC)

My motivation for creating an annotated SVG version of this image is that I'm trying to get this article promoted to featured article status within the next 3–6 months. Seppi333 (Insert 2¢) 21:52, 27 November 2017 (UTC)

Sure! I'll do it this weekend at the very latest; maybe tomorrow. --Slashme (talk) 23:35, 27 November 2017 (UTC)

Thanks!

Seppi333 (Insert 2¢) 23:49, 27 November 2017 (UTC)

Duplicate pathways that should be merged into 1

Duplicated pathway (1)

Duplicated pathway (2)

@Slashme: I've asked for feedback on the annotated diagram at WT:MCB#Template:Leucine metabolism in humans; so, it might be best to wait until tomorrow for other editors to provide their suggestions for changes before working on the svg version. Seppi333 (Insert 2¢) 20:36, 2 December 2017 (UTC)

OK, will check there before starting. --Slashme (talk) 00:07, 3 December 2017 (UTC)

@Slashme: I don't expect that the section on WT:MCB is going to garner further input; so, if you're still willing to create the svg image background, let me know once you've uploaded it and I'll update the annotated image. Seppi333 (Insert 2¢) 22:04, 16 December 2017 (UTC)

@Slashme: The consensus at WT:MCB is that the image should be recreated with the two pathways shown on the right merged into a single pathway so that these compounds aren't shown twice in the image. If you're still interested in recreating this image in svg format, let me know; otherwise, I intend to draw this myself when I have the time. Seppi333 (Insert 2¢) 05:45, 24 January 2018 (UTC)

Draft version of `{{Leucine metabolism in humans}}` (under construction)

Annotated image and reflist

Leucine metabolism in humans

L-Leucine

Branched-chain amino
acid aminotransferase

Muscle: α-Ketoisocaproate (α-KIC)

Liver: α-Ketoisocaproate (α-KIC)

Branched-chain α-ketoacid
dehydrogenase (mitochondria)

KIC-dioxygenase
(cytosol)

Isovaleryl-CoA

β-Hydroxy
β-methylbutyrate
(HMB)

Excreted
in urine
(10–40%)

HMB-CoA

β-Hydroxy β-methylglutaryl-CoA
(HMG-CoA)

β-Methylcrotonyl-CoA
(MC-CoA)

β-Methylglutaconyl-CoA
(MG-CoA)

CO₂

O₂

CO₂

H₂O

CO₂

H₂O

(liver)
HMG-CoA
lyase

Enoyl-CoA hydratase

Isovaleryl-CoA
dehydrogenase

β-Hydroxybutyrate
dehydrogenase

Unknown
enzyme

Human metabolic pathway for HMB and isovaleryl-CoA relative to L-leucine.^[1]^[2]^[3] Of the two major pathways, L-leucine is mostly metabolized into isovaleryl-CoA, while only about 5% is metabolized into HMB.^[1]^[2]^[3]

References

^ ^a ^b Wilson JM, Fitschen PJ, Campbell B, Wilson GJ, Zanchi N, Taylor L, Wilborn C, Kalman DS, Stout JR, Hoffman JR, Ziegenfuss TN, Lopez HL, Kreider RB, Smith-Ryan AE, Antonio J (February 2013). "International Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB)". Journal of the International Society of Sports Nutrition. 10 (1): 6. doi:10.1186/1550-2783-10-6. PMC 3568064. PMID 23374455.
^ ^a ^b Zanchi NE, Gerlinger-Romero F, Guimarães-Ferreira L, de Siqueira Filho MA, Felitti V, Lira FS, Seelaender M, Lancha AH (April 2011). "HMB supplementation: clinical and athletic performance-related effects and mechanisms of action". Amino Acids. 40 (4): 1015–1025. doi:10.1007/s00726-010-0678-0. PMID 20607321. S2CID 11120110. HMB is a metabolite of the amino acid leucine (Van Koverin and Nissen 1992), an essential amino acid. The first step in HMB metabolism is the reversible transamination of leucine to [α-KIC] that occurs mainly extrahepatically (Block and Buse 1990). Following this enzymatic reaction, [α-KIC] may follow one of two pathways. In the first, HMB is produced from [α-KIC] by the cytosolic enzyme KIC dioxygenase (Sabourin and Bieber 1983). The cytosolic dioxygenase has been characterized extensively and differs from the mitochondrial form in that the dioxygenase enzyme is a cytosolic enzyme, whereas the dehydrogenase enzyme is found exclusively in the mitochondrion (Sabourin and Bieber 1981, 1983). Importantly, this route of HMB formation is direct and completely dependent of liver KIC dioxygenase. Following this pathway, HMB in the cytosol is first converted to cytosolic β-hydroxy-β-methylglutaryl-CoA (HMG-CoA), which can then be directed for cholesterol synthesis (Rudney 1957) (Fig. 1). In fact, numerous biochemical studies have shown that HMB is a precursor of cholesterol (Zabin and Bloch 1951; Nissen et al. 2000).
^ ^a ^b Kohlmeier M (May 2015). "Leucine". Nutrient Metabolism: Structures, Functions, and Genes (2nd ed.). Academic Press. pp. 385–388. ISBN 978-0-12-387784-0. Retrieved 6 June 2016. Energy fuel: Eventually, most Leu is broken down, providing about 6.0kcal/g. About 60% of ingested Leu is oxidized within a few hours ... Ketogenesis: A significant proportion (40% of an ingested dose) is converted into acetyl-CoA and thereby contributes to the synthesis of ketones, steroids, fatty acids, and other compounds
Figure 8.57: Metabolism of L-leucine

[ISSN_position_stand_2013-1] Wilson JM, Fitschen PJ, Campbell B, Wilson GJ, Zanchi N, Taylor L, Wilborn C, Kalman DS, Stout JR, Hoffman JR, Ziegenfuss TN, Lopez HL, Kreider RB, Smith-Ryan AE, Antonio J (February 2013). "International Society of Sports Nutrition Position Stand: beta-hydroxy-beta-methylbutyrate (HMB)". Journal of the International Society of Sports Nutrition. 10 (1): 6. doi:10.1186/1550-2783-10-6. PMC 3568064. PMID 23374455.

[HMB_athletic_performance-related_effects_2011_reviewb-2] Zanchi NE, Gerlinger-Romero F, Guimarães-Ferreira L, de Siqueira Filho MA, Felitti V, Lira FS, Seelaender M, Lancha AH (April 2011). "HMB supplementation: clinical and athletic performance-related effects and mechanisms of action". Amino Acids. 40 (4): 1015–1025. doi:10.1007/s00726-010-0678-0. PMID 20607321. S2CID 11120110. HMB is a metabolite of the amino acid leucine (Van Koverin and Nissen 1992), an essential amino acid. The first step in HMB metabolism is the reversible transamination of leucine to [α-KIC] that occurs mainly extrahepatically (Block and Buse 1990). Following this enzymatic reaction, [α-KIC] may follow one of two pathways. In the first, HMB is produced from [α-KIC] by the cytosolic enzyme KIC dioxygenase (Sabourin and Bieber 1983). The cytosolic dioxygenase has been characterized extensively and differs from the mitochondrial form in that the dioxygenase enzyme is a cytosolic enzyme, whereas the dehydrogenase enzyme is found exclusively in the mitochondrion (Sabourin and Bieber 1981, 1983). Importantly, this route of HMB formation is direct and completely dependent of liver KIC dioxygenase. Following this pathway, HMB in the cytosol is first converted to cytosolic β-hydroxy-β-methylglutaryl-CoA (HMG-CoA), which can then be directed for cholesterol synthesis (Rudney 1957) (Fig. 1). In fact, numerous biochemical studies have shown that HMB is a precursor of cholesterol (Zabin and Bloch 1951; Nissen et al. 2000).

[Leucine_metabolism-3] Kohlmeier M (May 2015). "Leucine". Nutrient Metabolism: Structures, Functions, and Genes (2nd ed.). Academic Press. pp. 385–388. ISBN 978-0-12-387784-0. Retrieved 6 June 2016. Energy fuel: Eventually, most Leu is broken down, providing about 6.0kcal/g. About 60% of ingested Leu is oxidized within a few hours ... Ketogenesis: A significant proportion (40% of an ingested dose) is converted into acetyl-CoA and thereby contributes to the synthesis of ketones, steroids, fatty acids, and other compounds
Figure 8.57: Metabolism of L-leucine

[1]

[2]

[3]