Guineesine (or guineensine) is an

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

isolated from

long pepper Long pepper (''Piper longum''), sometimes called Indian long pepper or ''thippali'', is a flowering vine in the family Piperaceae, cultivated for its fruit, which is usually dried and used as a spice and seasoning. Long pepper has a taste simil ...

(''Piper longum'') and

black pepper Black pepper (''Piper nigrum'') is a flowering vine in the family Piperaceae, cultivated for its fruit, known as a peppercorn, which is usually dried and used as a spice and seasoning. The fruit is a drupe (stonefruit) which is about in diame ...

(''Piper nigrum'').

Research

Guineensine inhibits the cellular reuptake of

anandamide Anandamide (ANA), also known as ''N''-arachidonoylethanolamine (AEA), is a fatty acid neurotransmitter. Anandamide was the first endocannabinoid to be discovered: it participates in the body's endocannabinoid system by binding to cannabinoid rec ...

and 2-arachidonoylglycerol in a

mouse model A model organism (often shortened to model) is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the working ...

( EC₅₀ = 290 nM). This causes an increase in the activity of the two

neurotransmitter A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neuro ...

s which are classified as

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, es ...

cannabinoids Cannabinoids () are several structural classes of compounds found in the cannabis plant primarily and most animal organisms (although insects lack such receptors) or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tet ...

. Guineesine can dose-dependently produce cannabimimetic effects in a mouse model which are indicated by potent catatonic,

analgesic An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It ...

, hypo-locomotive and hypo-thermic effects. In addition, the analgesic and catatonic effects were reversed by the

cannabinoid receptor type 1 Cannabinoid receptor type 1 (CB1), also known as cannabinoid receptor 1, is a G protein-coupled cannabinoid receptor that in humans is encoded by the ''CNR1'' gene. The human CB1 receptor is expressed in the peripheral nervous system and central ...

(CB1)

inverse agonist In pharmacology, an inverse agonist is a drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist. A neutral antagonist has no activity in the absence of an agonist or inverse agon ...

rimonabant Rimonabant (also known as SR141716; trade names Acomplia, Zimulti) is an anorectic antiobesity drug that was first approved in Europe in 2006 but was withdrawn worldwide in 2008 due to serious psychiatric side effects; it was never approved in t ...

. Guineesine is also a

monoamine oxidase inhibitor Monoamine oxidase inhibitors (MAOIs) are a class of drugs that inhibit the activity of one or both monoamine oxidase enzymes: monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B). They are best known as effective antidepressants, espe ...

(MAOI) ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

'' ( IC₅₀ = 139.2 μM).

References

{{Reflist, 30em Alkaloids found in plants Benzodioxoles Carboxamides Monoamine oxidase inhibitors Cannabinoids Endocannabinoid reuptake inhibitors Guineesine(Guineensine) was first isolated,studied and named from Piper guineense Schum and Thonn. ,21. OKOGUN, J.I. and Ekong, D.E.U. 1974 Extracts from the Fruits of the Piper guineense. Schum and Thonn. J. Chem. Soc. Perkin Transactions I, 1974, 2195-2198. 2. Okwute, S.K. OKOGUN, J.I. and Okorie, D.A. 1984 Revised Structure and Synthesis of Piperolein acids; Guineensine and Wisanine from Piper guineense, TETRAHEDRON, 40, 2541-2545.