Kratom (Mitragyna speciosa) Alkaloids and Effects

Note: this list of alkaloids is not complete. Furthermore, more studied need to be conducted to determine their full potential.


Mitragynine: Indole alkaloid. Analgesic, antidiarrheal, adrenergic, antitussive, antimalarial, possible psychedelic (5-HT2A) antagonist. Mitragynine is the primary alkaloid in kratom, and is responsible for majority of its effects. Roughly 66% of total alkaloid content found in Kratom leaf.

Paynantheine: Indole alkaloid. Known as a muscle relaxer. Makes up 8.6% to 9% of total alkaloid contents in Kratom leaf. Second most abundant alkaloid.

Speciogynine: Diastereomer of mitragynine. Also a muscle relaxer. Makes up 6.6% to 7% of total kratom alkaloid contents, representing the third most abundant alkaloid.

7-hydroxymitragynine: Potent analgesic and mu-opioid agonistantitussive, and antidiarrheal. Along with mitragynine, 7-hydroxymitragynine is responsible for the primary effects of Kratom. It represents 2% of total alkaloid content found in Kratom leaf, though this varies widely between different strains of leaves.

Mitraphylline: Oxindole alkaloid. Vasodilator, antihypertensive, muscle relaxer, diuretic, antiamnesic, anti-leukemic, possible immunostimulant. Makes up less than 1% of total alkaloid contents in Kratom.

IsomitraphyllineImmunostimulant, anti-leukemic. Makes up less than 1% of total alkaloid content found in Kratom.

Speciophylline: Indole alkaloid. Also contained in Chinese Cat’s claw (Uncaria tomentosa). Possibly anti-leukemic. Makes up less than 1% of total alkaloid contents in Kratom.

Rhynchophylline: Vasodilator, antihypertensive, calcium channel blocker,
antiaggregant, anti-inflammatory, antipyretic (fever reducing), antiarrhythmic, and anthelmintic (treatment of parasitic worms). It is a also non-competitive NMDA antagonist, and appears to also have effects on dopamine and 5-HT receptors. Also contained in Chinese Cat’s claw (Uncaria tomentosa). Similar chemical structure to mitragynine, and represents less than 1% of total alkaloid content found in kratom leaf.

Isorhynchophylline: Immunostimulant, antihypertensive and neuroprotective. Makes up less than 1% of total alkaloid content found in Kratom.

Ajmalicine (Raubasine): Cerebrocirculant, antiaggregant, sedative, anti-adrenergic (at alpha-1), anticonvulsant, and a smooth muscle relaxer. It’s structurally related to alkaloids from yohimbe. According to ‘Alkaloids: Biochemistry, Ecology, and Medical Applications‘, ajmalicine “depletes peripheral noradrenaline stores, resulting in a decrease of peripheral resistance and blood pressure. It also causes depletion of catecholamine and serotonin stores in the brain, heart, and many other organs”. Ajmalicine is also found in Rauwolfia serpentina.

Akuammigine – an indole alkaloid associated with the seeds of Picralima nitida (akaumma). Structurally similar to yohimbine and mitragynine.

Ciliaphylline: antitussive, analgesic. Makes up less than 1% of total alkaloid content found in Kratom.

Corynantheidine (rauhimbine): μ -opioid antagonist, also found in Yohimbe. It’s related to ajmalicine, and is a diastereomer of yohimbine. Like ajmalicine, it is an α1-adrenergic and α2-adrenergic receptor antagonist with 10x greater affinity for the α1-adrenergic receptor. Makes up 1% of total alkaloid content found in Kratom leaf.

Corynoxeine: Calcium channel blocker. Makes up less than 1% of total alkaloid content found in Kratom leaf.

Corynoxine A and BDopamine mediating anti-locomotives, meaning that they act as somewhat of a sedative. Also found in Chinese Cat’s Claw (Uncaria tomentosa). Research that suggests they may help with Parkinson’s. Makes up less than 1% of total alkaloid content found in Kratom.

Epicatechin: Antioxidant, antibacterialantidiabetic, antiaggregantantihepatiticanti-inflammatory, antimutagenic, anti-leukemic, antiperoxidant, antiviral, potential cancer preventative, and alpha-amylase inhibitorOne preliminary study even claims that it may reduce myostatin, which would result in muscle growth and improved strength. Also found in dark chocolate, green tea, and grapes.

9-HydroxycorynantheidinePartial opioid agonist. One study found that “9-Hydroxycorynantheidine inhibited electrically stimulated guinea-pig ileum contraction, but its maximum inhibition was weaker than that of mitragynine and its effect was antagonized by naloxone, suggesting that 9-hydroxycorynantheidine possesses partial agonist properties on opioid receptors”

Isomitrafoline: Makes up less than 1% of total alkaloid content found in Kratom leaf.

Isopteropodine: Immunostimulant, antimicrobial.

Isospeciofoline: Makes up less than 1% of total alkaloid content found in Kratom leaf.

Mitraciliatine: Makes up less than 1% of total alkaloid content found in Kratom leaf.

Mitragynine oxindole B. Makes up less than 1% of total alkaloid content found in Kratom leaf.

Mitrafoline: Makes up less than 1% of total alkaloid content found in Kratom leaf.

Mitraversine: Found in Mitragyna parvifolia, and may also be in Mitragyna speciosa

SpeciociliatineDiastereomer (C3 stereoisomer) of mitragynine. Weak opioid agonist. May inhibit acetylcholine release from presynaptic nerve through means other than opioid receptor stimulation. 0.8% to 1% of total alkaloid content of kratom leaf. Unique to Kratom.

Speciofoline: Potential analgesic and antitussive. Patented (US3324111) by Smith Kline (of Glaxo Smith Kline) in 1964. Also patented (US20100209542) by the University of Massachusetts Medical School and University of Mississippi in 2009 to treat opiate withdrawal. As of February 18, 2019, the patent is listed as abandoned.

Stipulatine: More research needed

TetrahydroalstonineHypoglycemic, anti-adrenergic (at alpha-2).


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