In pyrimidine nucleotides, the nitrogenous base is covalently linked to the C-1' carbon of the pentose sugar via a $\beta$-N-glycosidic bond through the N-1 atom of the pyrimidine ring (in purines, it involves N-9).

In oligonucleotide shorthand notation, adjacent nucleosides are linked by $3'-5'$ phosphodiester linkages, represented by the letter 'p' positioned between nucleotide symbols.

NAD (Nicotinamide Adenine Dinucleotide), Coenzyme A (contains 3'-phosphoadenosine diphosphate), and FMN (Flavin Mononucleotide) all contain nucleotide moieties. TPP (Thiamine pyrophosphate) is a phosphorylated vitamin B1 derivative lacking a nucleotide base/ribose core.

Phosphatidylinositol and its phosphorylated derivatives (PIP2, IP3, DAG), Sphingomyelin (via SMase pathway), and Ceramide act as crucial lipid second messengers regulating cell growth, differentiation, and apoptosis. Plasmalogens serve primarily as structural and antioxidant ether lipids.