The first contribution describes apolar and polar molecular fossils and,
in particular biomarkers, along the lines usually followed in organic
chemistry textbooks, and points to their bioprecursors when available.
Thus, the apolar compounds are divided in linear and branched alkanes
followed by alicyclic compounds and aromatic and heterocyclic molecules,
and, in particular, the geoporphyrins. The polar molecular fossils
contain as functional groups or constituent units ethers, alcohols,
phenols, carbonyl groups, flavonoids, quinones, and acids, or are
polymers like kerogen, amber, melanin, proteins, or nucleic acids. The
final sections discuss the methodology used and the fundamental
processes encountered by the biomolecules described, including
diagenesis, catagenesis, and metagenesis.
The second contribution covers the distribution of phthalides in nature
and the findings in the structural diversity, chemical reactivity,
biotransformations, syntheses, and bioactivity of natural and
semisynthetic phthalides.