Environmental Engineering Reference
In-Depth Information
demonstrate the current diversity in functionality and to ensure the reader has the
broadest possible vision when considering bio-based chemicals for any process
or product. Some entries in Table 4.5 only contain selected examples from a
larger range of molecules. For example, all natural amino acids are derivable
from biomass, either from fermentation or protein depolymerisation, but only
aspartic and glutamic acid are highlighted in the list below. Lammens
et al
. ana-
lysed a range of biomass sources for the amino acid mass fraction following
protein hydrolysis and concluded that aspartic and glutamic acid were the most
abundant residues and therefore the most likely to become key platform mole-
cules [98]. The structures shown for terpenes (α-pinene and d-limonene) and
fatty acids (lauric acid) are also only representative examples of a wider range of
possible platform molecules. PHAs, produced via sugar-consuming bacteria, can
be hydrolysed yielding various hydroxy acids, with only representative examples
shown in Table 4.5.
OH
OH
OH
OH
HO
O
Reduction
Dehydration
O
OH
HO
OH
HO
O
OH
OH
OH
D-glucose
OH
D-sorbitol
Isosorbide
OH
OH
OH
HO
O H
O
Reduction
Dehydration
OH
O
HO
H
O
OH
HO
OH
OH
O
OH
D-mannose
D-mannitol
Isomannide
OH
OH
OH
HO
HO
O
Reduction
Dehydration
O
OH
HO
OH
O
HO
OH
OH
OH
D-idose
OH
D-iditol
Isoidide
Figure 4.13
Three possible isomers of the 1,4:3,6-dianhydrohexitols derivable from platform
molecules.
