Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: cheryl j on 19/10/2013 16:02:38

Title: What's an alkaloid?
Post by: cheryl j on 19/10/2013 16:02:38

In an explanation of taste in the sensory system it says that the receptors for bitterness detect alkaloids and other compounds. The explanation was a lot less clear cut than for other receptors that detect sugars or sodium ions or H+ ions in acid.

Title: Re: What's an alkaloid?
Post by: CliffordK on 21/10/2013 11:46:12

Alkaloids (http://en.wikipedia.org/wiki/Alkaloid) are a group of naturally occurring nitrogen containing compounds.  Most have the nitrogen incorporated in a cyclic structure, and most are basic due to the nitrogen. 

According to the notes, most are bitter, and many are toxic, and are produced by plants to discourage animals from eating them.

Apparently there is quite a diversity between different alkaloids.

Title: Re: What's an alkaloid?
Post by: chiralSPO on 23/10/2013 15:18:58

Alkaloids are a huge class of bioactive compounds. Many find use as pharmaceuticals, recreational drugs and poisons. Well known plant-derived alkaloids include morphine, cocaine, mescaline, atropine, quinine, strychnine, caffeine, etc.

Title: Re: What's an alkaloid?
Post by: cheryl j on 04/11/2013 01:24:53

Thanks, that helps.

Title: Re: What's an alkaloid?
Post by: alancalverd on 04/11/2013 08:13:33

IIRC the "bitter" receptors detect electron donors, which will include OH- ions from dissolved alkalis and organic donors such as alkaloids. Seems odd for a textbook to mention alkaloids before alkalis. Maybe the authors are more familiar with cocaine than Drano. O tempora, o mores.

(Off to the evil laboratory to develop sweet cocaine. I shall rule the world. Sneering laugh.)

Title: Re: What's an alkaloid?
Post by: RD on 04/11/2013 13:32:54

Quote from: alancalverd on 04/11/2013 08:13:33

... Off to the evil laboratory ...

While you're in the evil laboratory the "redneck deathray" needs tweaking [:)]

Quote from: dailymail.co.uk

Two men, including a member of the KKK, have been arrested after trying to build a portable X-ray machine to allegedly kill President Obama ...

http://www.dailymail.co.uk/news/article-2344657/KKK-member-friend-built-truck-mounted-death-ray-wanted-kill-President-Obama-Muslims-revenge-Boston-bombings.html

Title: Re: What's an alkaloid?
Post by: cheryl j on 04/11/2013 14:23:15

Quote from: alancalverd on 04/11/2013 08:13:33

IIRC the "bitter" receptors detect electron donors, which will include OH- ions from dissolved alkalis and organic donors such as alkaloids. Seems odd for a textbook to mention alkaloids before alkalis. Maybe the authors are more familiar with cocaine than Drano. O tempora, o mores.

(Off to the evil laboratory to develop sweet cocaine. I shall rule the world. Sneering laugh.)

The theory was that these receptors make humans averse to poisonous plants. They also make kids dislike some green vegetables, because those receptors are more sensitive when you're young. So you should also make some better tasting brussel sprouts in the evil lab.

Title: Re: What's an alkaloid?
Post by: lucas2 on 25/11/2013 08:01:24

Alkaloids are present in organisms (mainly plants) in a class of basic nitrogen compounds,
most complex ring structure, and more nitrogen contained in the ring,
there are significant biological activity, are herbal in one important active ingredients.