Ultrasonic Kratom Extraction
Ultrasonication is a highly effective, simple and reliable technique to produce alkaloid-rich extracts from kratom leaves (Mitragyna speciosa). Sonication releases bioactive compounds such as mitragynine and 7-hydroxymitragynine from the plant cells so that they can be isolated. Ultrasonic extraction provides higher yields in a very short extraction time.
Kratom and Mitragynine
Mitragynine and 7-hydroxymitragynine are the indole alkaloids of Mitragyna speciosa, also known as Kratom. Both compounds act as opioid-receptor antagonist and are known for their pain-relieving effects. 7-hydroxymitragynine is a highly potent painkilling substance. Unlike mitragynine, which is abundantly present in Kratom leaves, 7-hydroxymitragynine is found only in small amounts. However, due to its high potency, 7-hydroxymitragynine relieves even worst pain and is also known to ease opiate withdrawal symptoms.
Dried kratom leaves contain approx. 1-6% mitragynine and approx. 0.01 – 0.04% of 7-hydroxymitragynine. Kratom is natural botanical ingredient that can be used as dietary supplements or as pharmaceutical in form of powders, capsules or tinctures to relieve pain, stimulate or act as natural help for opioid withdrawal.
The bioactive compounds of kratom, e.g., the alkaloids mitragynine and 7-hydroxymitragynine, are stored in the cells of the kratom plant. In order to make them bioavailable and to release their psychoactive medicinal effects, the cells walls must be broken down and the bioactive compounds must be isolated from the cell interior. Ultrasonication is a highly efficacious method for the extraction of botanical compounds and is therefore the preferred kratom extraction technique.
Ultrasonicator UP400St for highly efficient kratom extraction
Ultrasonic Extraction of Kratom Alkaloids
Ultrasonic extraction is a very effective method to release the key psychoactive compounds mitragynine and 7-hydroxymitragynine (7-HMG) as well as more than 40 other bioctive compounds, including about 25 alkaloids (e.g. ajmalicine, mitraphylline, mitragynine pseudoindoxyl, rhynchophylline) from kratom.
The most widely used compounds of Mitragyna speciosa (kratom) are the alkaloids mitragynine (MG), 7-hydroxymitragynine, which are known as potent painkilling substances. 7-hydroxymitragynine is an opioid-antagonist, which helps patients to withdraw from opioids. Both substances can be successfully released from the plant’s cell matrix by sonication. Kratom extracts can be ultrasoncially produced either using alcohol, water or aqueous ethanol as solvent. The selection of solvent influences the effects of the kratom extract.
Ethanol and aqueous ethanol (i.e., ethanol/water) give the highest raw extract yields due to their polarity.
What is the Ideal Solvent for Ultrasonic Kratom Extraction?
Ultrasonication as extraction method is compatible with any solvent. You are free to choose the solvent that you like the most. However, for optimal extraction results of kratom, some solvents are better for dissolving kratom alkaloids.
The effect of the kratom extract is influenced by the solvent as polar and non-polar solvents selectively dissolve more of specific compounds respectively:
- Aqueous Ethanol: Aqueous ethanol means a mixture of water and ethanol. The ratio of water to ethanol can be adjusted to requirements. The use of aqueous ethanol as a solvent has several advantages over the use of water or ethanol alone. First, the addition of ethanol to water can improve the solubility of certain bioactive compounds that are not very soluble in water alone, such as some phenolic compounds and triterpenoids. Second, the use of aqueous ethanol can result in higher extraction yields compared to water or ethanol alone, as it can extract a wider range of bioactive compounds.
For kratom, a higher concentration of ethanol (60-80%) is a good choice as it results in a very efficient extraction alkaloids such as mitragynine, phenolic compounds, terpenes and triterpenoids. At the same time, other water-soluble plant compounds are extracted too – resulting in a full spectrum extract. - Water: Water is a common solvent for the extraction of bioactive compounds from plants. The main kratom alkaloid mitragynine is not water-soluble, so water is not ideal for kratom extraction.
- Ethanol: Ethanol is a very polar solvent that is commonly used for the extraction of mitragynine, phenolic compounds, terpenes and triterpenoids.
- Methanol or Acetone: Methanol and acetone are non-polar solvents that can be used for the extraction of kratom. However, methanol and acetone are both flammable and toxic, so they should be used with caution.
For ultrasonic kratom extraction, we recommend aqueous ethanol as solvent. A mixture of water and food-grade ethanol is a non-toxic solvent, which can be easily removed after extraction by distillation or roto-evaporation.
Due to the specific dissolving capability of different solvents, kratom extracts can exhibit distinct properties. Kratom extract isolated with pure ethanol or a high ethanol ratio shows less stimulating properties, whilst the relaxing, anxiety-reducing effects of mitragynine are more pronounced. Ultrasonic extraction can be used with various kinds of solvent and gives you the option of producing kratom extracts with different properties.
Read more about alkaloid extraction from plant material using a probe-type ultrasonicator!
Case Study for Ultrasonic Kratom Extraction
Research has already investigated and proven the ultrasonically assisted extraction as a procedure, which increases the extraction efficiency and yield of released mitragynine.
Orio et al. 2011 compared various extraction techniques such as ultrasound-assisted extraction, microwave-assisted extraction and supercritical carbon dioxide extraction, using methanol, ethanol, water and binary mixtures. The probe-type ultrasonicator gave the highest yield in mitragynine. Since ultrasonic extraction processes can be linearly scaled up to industrial production, it is the most effective method to produce larger quantities of the alkaloid.
An initial freeze-drying coupled with ultrasonic extraction has been found most efficient when a combination of CHCl3 : MeOH 1:4 (v/v) at pH 9.5 was used. A low extraction temperature between 25 and 45°C helps to avoid the degradation of the bioactive compounds.
For the ultrasonic extraction, 5 g of the pulverised freeze-dried Kratom leaves are placed in a beaker containing 200 mL of CHCl3:CH3OH, 1:4(v/v), which is placed in an ice bath to keep the temperature during sonication low. The sample is sonicated with an ultrasonic homogenizer UP200Ht (200W, 26kHz; see picture left). The UP200Ht is set to 100% amplitude and 50% cycle mode and the sample is sonicated for approx. 4 min. Afterwards, the leaf extract is filtered through a filter paper and the filtrate was allowed to dry on an evaporating dish placed on a water bath.
Ultrasonic extraction results in high quality extracts and convinces by high yields, fast processing time, safe and easy operation, low investment cost as well as environmental-friendliness.
Ultrasonic extractor UIP1000hdT with stirrer for extraction of phytochemicals from herbs and other plants.
Ultrasonic Extractors for Kratom Alkaloids
Hielscher Ultrasonics is your long-experienced supplier of high-performance ultrasound extractors. Offering the full range from small hand-held ultrasonicators to fully industrial ultrasonic extractors for continuous inline processing, we will recommend you an ultrasonic system tailored to your process requirement.
All our ultrasonicators can be run in 24/7 operation. Depending on your raw material and extraction volume, you can decide between batch sonication and inline sonication using an ultrasonic flow-through reactor.
The portfolio of ultrasonicators and accessories (such as sonotrodes, Cascatrodes, booster horns, flow cells, reactors etc.) allow you to assembly a setup optimized for your process goals.
The table below gives you an indication of the approximate processing capacity of our ultrasonic extactors:
| Batch Volume | Flow Rate | Recommended Devices |
|---|---|---|
| 1 to 300mL | 10 to 100mL/min | UP50H |
| 1 to 500mL | 10 to 200mL/min | UP100H |
| 10 to 2000mL | 20 to 400mL/min | UP200Ht, UP400St |
| 0.1 to 20L | 0.2 to 4L/min | UIP2000hdT |
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Literature / References
- Orio, Laura; Alexandru, Lavinia; Cravotto, Giancarlo; Mantegna, Stefano; Barge, Alessandro (2012): UAE, MAE, SFE-CO2 and classical methods for the extraction of Mitragyna speciosa leaves. Ultrasonics Sonochemistry 19 (2012) 591–595.
- Hakim Mas Haris et al. (2013): An Optimised Recovery of Mitragynine from Mitrgyna Speciosa Using Freeze Drying and Ultrasonic-Assisted Extraction Method. The Experiment Vol. 15(3), 2013. 1077-1083.
Facts Worth Knowing
Kratom
Kratom is well known for its main psychoactive components mitragynine (MG) and 7‐hydroxymitragynine (7‐HMG), which are found in the leaves of Mitragyna speciosa.
Kratom is a Thai term and describes both, the tree as well as the preparation techniques to consume the leaves. Mitragyna speciosa Korth. is an evergreen tree in the coffee family (Rubiaceae family) native to Southeast Asia.
Opioid Antagonists
An agonist is a drug that activates certain receptors in the brain. Full agonist opioids activate the opioid receptors in the brain fully resulting in the full opioid effect. Examples of full agonists are heroin, oxycodone, methadone, hydrocodone, morphine, opium and others.
An antagonist is a drug that blocks opioids by attaching to the opioid receptors without activating them. Antagonists cause no opioid effect and block full agonist opioids. Examples are naltrexone and naloxone. Naloxone is sometimes used to reverse a heroin overdose.
Terpenes vs Terpenoids
Terpenes are pure hydrocarbons based on combinations of the isoprene unit, whilst terpenoids are modified by oxidation. This means, terpenoids are compounds related to terpenes, distinguished by an oxygen functionality or molecular rearrangements. Although terpenes and terpenoids are different types of compounds, the both terms are often colloquially used as interchangeable.