Kratom Extraction Method Found

[Nunyabiz]

I found this while looking for solvent solubilty of kratom actives. The first paragraph seems do-able. For me at least. Never done chroma though so it might take a little studying to learn about this whole process. Here it is.



Extraction and isolation
Big, young leaves were powdered (165.5 g) and extracted five times with hot methanol. The solvent was concentrated under reduced pressure to give a crude extract (53.5 g), a part of which was dissolved in 10% aqueous acetic acid (AcOH). The insoluble material was removed by filtration through Celite to give the AcOH-insoluble fraction solution (AcOH-insoluble fraction, 50.3 g). The aqueous layer was basified with Na2CO3 at 0°C and extracted with chloroform (CHCl3). The organic layer was washed with water, dried over MgSO4, and then evaporated to give the crude base fraction (2.43 g). The aqueous layer was further extracted with n-Butanol (BuOH), which was concentrated under reduced pressure to yield the n-BuOH fraction (4.77 g). A part of the residual aqueous solution (10 ml) was lyophilized to give a hygroscopic solid (ca. 2 g), which was isolated with ethanol using a Soxhlet extractor in order to remove the inorganic materials. The ethanol extract was evaporated to give a residue containing the water-soluble organic materials (water-soluble fraction, 1.08 g).
The crude base fraction (2.0 g), which exhibited an opioid agonistic effect on the guinea-pig ileum, was purified by SiO2 column chromatography (6 × 17 cm) using CHCl3/ethyl acetate (AcOEt) (9:1, 370 ml; fraction A), CHCl3/AcOEt (4:1, 240 ml; fraction B), CHCl3/AcOEt (1:1, 320 ml; fraction C), AcOEt (80 ml; fraction D), MeOH/AcOEt (1:19, 120 ml; fraction E), MeOH/AcOEt (1:4, 160 ml; fraction F), MeOH/AcOEt (1:1, 80 ml; fraction G), and MeOH (150 ml; fraction H). The combined fractions C and D were further purified by SiO2 column chromatography (3 × 17 cm) using an n-hexane/AcOEt (3:2, 1:1, 1:5, 30 ml each) gradient that afforded 24 fractions. Fractions 2–8 contained mitragynine (1343 mg, 66% based on the crude base, [α]D24: –126° {c 1.2, CHCl3}) and fractions 18–22 yielded 7-hydroxymitragynine (40 mg, 2% based on the crude base, [α]D23: + 47.9° {c

10
, 2.5 × 10 cm) with MeOH/CHCl3 (1:9, 3 mL/min) to provide speciociliatine (t: 18 min, 15 mg, 0.8% based on the crude base, [α]0.55, CHCl3}). From fraction E, paynantheine (178 mg, 8.9% based on the crude base, [α]D25: + 29.4° (c 1.2, CHCl3}) was obtained. Fraction F afforded speciogynine (132 mg, 6.6% based on the crude base, [α]D24: + 26.8° (c 0.85, CHCl3}). Fraction G was subjected to MPLC (SiO2RD24: –10.5° (c 1.2, CHCl3}). The isolated compounds were identified by direct comparison with the corresponding authentic samples. The purity (> 99%) of the above compounds was checked by HPLC and 1H-NMR (500 MHz) analyses.

[EmmisonJ]

nice find, it gets mitragynine and 7-hydroxymitragynine (which explains the different extraction solvents)! now we just need to adapt it as otc as possible and see if it's still as effective.

*substitute sodium bicarbonate for sodium carbonate
*substitute dcm for chloroform
*not sure about BuOH