It's a brazilian paper
here it goes...
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(AN. FAC. MED. UNIV. RECIFE, V 21, ns 1-2, p. 9-33, JUN-DEC 1961)
ANTÔNIO CESÁRODE MELO
JACYREMA ALVES BANDEIRA
...
(A) CHEMICAL PART
We worked w/ roots of 'Jurema preta', from Arcoverde city, i.e. same origin of roots used by Prof. Gonçalves de Lima, meaning the same botanic classification as Mimosa hostilis Benth.
-New method to isolate Nigerin
(Dmt)-
Due to the abundance of tannins on the MhRB, we tried a tech to isolate the alkaloyd, avoiding interference of the said component on our work. We got good yields w/ the following tech:
The air dried root bark was ground
(how much?) , and treated under mechanical agitation w/ chloroform in presence of a diluted solution of NH
4OH, the upper layer showing pH 9.0. After filtration the solid matter was again extracted until it shows a weak response to Wagner reactive.
(I2 + KI). The chloroform extracts were reduced under rotovap until a syrup residue. This was treated several times w/ small portions of H
2SO
4 1N. The insoluble fraction was discarted. To the yellowish acid solution there was added chloroform and the pH was raised to 9.0 w/ diluted NH
4OH solution the chloroform layer was separated and this was repeated several times, the chloroform extracts were washed w/ water, until the water layer shows pH near 7. The chloroform layer was dried w/ Na
2SO
4, filtered and reduced under rotovap. The syrup residue was left 24h on a dessicator (NaOH pellets or conc. H
2SO
4), and crystslised as small yellowish concentric needles, m.p 40.0-43.0
oC. W/ this tech we got an 1.1% yield of crude alkaloyd content from the dried root bark.
Due to the colour of the crystals and the hygroscopic caracter, we tried a purification. We treated them in diluted H
2SO
4 solution (pH 2.0)under agitation w/ Merck activated charcoal (Methylenblautiter 10-11), after filtration we followed the procedure described above, and we got a 0.98% yield of a less hygroscopic whitish-yellowish crystals w/ m.p. 42.0-44.0
oC.
...
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good job, no?
ClearLight: The Ott's procedure uses chloroform as the first extraction solvent of the alkaline plant extract, but thanks anyway...