Scale-Up of Natural Products Isolation

The term “scale-up” has been interpreted here as increasing the output of the product. This can be achieved by increasing the scale of the operation or increasing the concentration of product in the starting material. In the former case, this chapter considers increasing scale to the maximum that can be conveniently operated in a laboratory environment. It thus excludes operations requiring “process-scale” facilities and chemical-engineering expertise. The chapter will consider mainly secondary microbial metabolites, but many aspects of isolation can also be applied to plant products. Although laboratory-scale facilities are assumed (and indeed all procedures discussed can be performed in an average chemical laboratory), for the larger scales of operation, e.g., the manipulation of 5- to 10-L volumes, a 750-mm-high bench is preferable to the standard 900-mm height. For operations requiring a fume cupboard, a “walk-in” type (i.e., having adjustable or removable benching) is recommended for the same reason. It has been assumed that 10-L fermenters and the apparatus associated with the processing of their contents is the maximum comfortable “laboratory” scale.