[Teslazar]

I'm no coffee chemistry expert either, but the following article indicates that the main adenosine receptor antagonists are caffeine, theophylline, and theobromine, all of which are found in coffee, tea, and chocolate (https://en.wikipedia.org/wiki/Adenosine_receptor). These three are all considered purines and therefore molybdenum would be involved in breaking them down. All three also have a diuretic effect (1) and Theobromine "shows strong diuretic effects" (2). That leads me to wonder if the ratio of these three varies significantly between coffees. I'm not sure but found one paper that shows that it does in cocoa (3), so perhaps it does in coffee also (there's probably research on coffee about this and I just didn't look hard enough).

(1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4383091 (2) http://medical-technologies.eu/upload/1.effects_of_coffee_al... (3) https://www.sciencedirect.com/science/article/pii/S030881460...

[hilbert42]

Thanks for the references. Just had an initial look and I'll return to them shortly. I was already aware the action of xanthine class drugs is centered on the adenosine receptors but I've little deeper knowledge of the subject, drugs and their biological action isn't my field so I'll have to take the documents slowly.

However, I've already noted in (2) a statement under Theobromine that it's a strong diuretic. That's interesting but what does strong mean here? I dislike simple-notion words in papers unless they're quantified (they require numbers against them).

That said, that's not a criticism of the paper having just glanced at it, and it has lots of other interesting stuff I'll need to read in detail. What's particularly relevant about the theobromine entry is this mention of the molecule's strong diuretic effect. When I made my point towards the end of my comment that that particular coffee 'likely had much more than the usual trace of theophyline in it', I deliberately left out reference to theobromine because I'd seen references that it was biologically less active than either theophyline and caffeine.

What was implied was that when evaluating the effects of coffee that theobromine was essentially considered irrelevant because it wasn't as biologically potent as either theophyline and caffeine and that its concentration in coffee is considerably lower than either of the other two.

Perhaps the earlier reference (which I've to locate again) was referring to theobromine's psychotropic effects rather than its diuretic effects. I'll now have to review and revise my understanding of common xanthines to correct my misunderstandings.

As someone who's not professionally involved in this field I sometimes think I'm a little mad for allowing my curiosity to get the better of me. :-)