Very‐Long‐Chain Wax Constituents from Primula veris and P. acaulis: Does the Paradigm of Non‐Branched vs. Branched Chain Dominance Universally Hold in all Plant Taxa?

• Published in: Chemistry & biodiversity 2021-07, Vol.18 (7), p.e2100285-n/a
• Main Authors: Živković Stošić, Milena Z., Radulović, Niko S., Genčić, Marija S., Ranđelović, Vladimir N.
• Format: Article
• Language: English
• Subjects: Alkanes; branched very-long-chain wax constituents; Chain branching; Constituents; Esters; Fatty acids; Isomers; Leucine; NMR; Nuclear magnetic resonance; Primula acaulis (L.) L; Primula veris; Primula veris L; Starters; thermal properties; unusual odd-even ratio; Waxes
• ISSN: 1612-1872; 1612-1880
• DOI: 10.1002/cbdv.202100285

Herein n‐, iso‐ and anteiso‐series of very‐long‐chained (VLC) alkanes (C21–C35), fatty acid benzyl esters (FABEs; C20–C32), and 2‐alkanones (C23–C35) were identified in the wax of Primula veris L. and P. acaulis (L.) L. (Primulaceae). For the very first time in a sample of natural origin, the presence of iso‐ and anteiso‐VLC FABEs and 2‐alkanones was unequivocally confirmed by synthetic work, derivatization, and NMR. It should be noted that the studied species produced unusually high amounts of branched wax constituents (e. g., >50 % of 2‐alkanones were branched isomers). The domination of iso‐isomers, probably biosynthesized from leucine‐derived starters, is a unique feature in the Plant Kingdom. The plant organ distribution of these VLC compounds in P. acaulis samples (different habitats and phenological phases) pointed to their possible ecological value. This was supported by a eutectic behavior of binary blends of FABEs and alkanes, as well as by high UV‐C absorption by FABEs.