| Summary: | ABSTRACT
Cassava is a known source of linamarin, but difficulties associated with its isolation have
prevented it from being exploited as a source. A batch adsorption process using activated
carbon at the appropriate contact time proved successful in its isolation with ultrafiltration
playing a pivotal role in the purification process. Result revealed that optimum purification
was obtained with increasing amount of crude cassava extract (CCE) purified. 60g of CCE
took 32 mins, 80 g, 34 mins while 100 g took 36 mins of contact time, where 1.7 g, 2.0 g and
2.5 g of purified product were obtained, respectively. The purification process in batch mode
was also carried out at different temperatures ranging from 25 to 65oC. Results showed that
purification increases with increase in temperature. In a bid to ascertain the moles of
linamarin adsorbed per pore volume of activated carbon used, the composite isotherm was
found to represent the measured adsorption data quite well. The adsorption of linamarin was
used to study the goodness of fit criteria (R2) for the entire process. Results showed that R2
value was best with decreasing amount of CCE purified (R2=1 for 60 g) at the temperature of
45oC. Compound elucidation of purified product by Picrate paper test, IR and 1HNMR
confirmed the structure of linamarin. Cytotoxic effects of linamarin on MCF-7, HT-29, and
HL-60 cells were determined using the 3 - (4, 5 – dimethylthiazol-2-yl) – 2, 5 –
diphenyltetrazolium bromide (MTT) assay. Cytotoxic effects were significantly increased in
the presence of linamarase, which catalysed the hydrolysis of linamarin to hydrogen cyanide.
A 10–fold decrease in the IC50 values obtained for linamarin or crude extract in the presence
of linamarase was determined for HL-60 cells. This study thus describes a method for the
isolation and purification of linamarin from cassava, as well as the potential of this
compound as an anticancer agent.
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