Complex sentence: For biosynthetic reasons, saccharides are almost always more abundant in nature as the "D" form, or structurally analogous to D-(+)-glyceraldehyde for sugars, the D/L nomenclature does not refer to the molecule's optical rotation properties.
Split into simpler sentences: For biosynthetic reasons, saccharides are almost always more abundant in nature as the "D" form, or structurally analogous to D-(+)-glyceraldehyde. For sugars, the D/L nomenclature does not refer to the molecule's optical rotation properties.