As shown in Figure 6B, the retention of monacolin K was increased with increasing phosphate concen- tration. This indicates that the phosphate concentration is an
important factor for repressing the extraction of monacolin K. Increasing the ethanol concentration resulted in a decrease in monacolin K retention because of the hydrophobic character of monacolin K. However, the extraction time would not cause a significant change in monacolin K retained. More than 90% monacolin K retention would be achieved when the extraction was carried out with 30% ethanol including more than 1.0% phosphate for 70 min.