Identification of Abies sibirica L. Polyprenols and Characterisation of Polyprenol-Containing Liposomes

Polyprenols in Ginkgo biloba; a review of their chemistry (synthesis of polyprenols and their derivatives), extraction, purification, and bioactivities

The Ginkgo biloba L. (GB) contains high bioactive compounds. To date, flavonoids and terpene trilactone have received the majority of attention in GB studies, and the GB has been utilized globally in functional food and pharmacological firms, with sales > $10 billion since 2017, while the other active components, for instance, polyprenols (a natural lipid) with various bioactivities have received less attention. Hence, this review focused on polyprenols' chemistry (synthesis of polyprenols and their derivatives) extraction, purification, and bioactivities from GB for the first time. The various extractions and purification methods (nano silica-based adsorbent, bulk ionic liquid membrane, etc.) were delved into, and their advantages and limitations were discussed. Besides, numerous bioactivities of the extracted Ginkgo biloba polyprenols (GBP) were reviewed. The review showed that GB contains some polyprenols in acetic esters' form. Prenylacetic esters are free of adverse effects. Besides, the polyprenols from GB have numerous bioactivities such as anti-bacterial, anti-cancer, anti-viral activity, etc. The application of GBPs in the food, cosmetics, and drugs industries such as micelles, liposomes, and nano-emulsions was delved into. Finally, the toxicity of polyprenol was reviewed, and it was concluded that GBP was not carcinogenic, teratogenic, or mutagenic, giving a theoretical justification for using GBP as a raw material for functional foods. This article will aid researchers to better understand the need to explore GBP usage.

The Biomedical Importance of the Missing Pathway for Farnesol and Geranylgeraniol Salvage

Isoprenoids are the output of the polymerization of five-carbon, branched isoprenic chains derived from isopentenyl pyrophosphate (IPP) and its isomer, dimethylallyl pyrophosphate (DMAPP). Isoprene units are consecutively condensed to form longer structures such as farnesyl and geranylgeranyl pyrophosphate (FPP and GGPP, respectively), necessary for the biosynthesis of several metabolites. Polyprenyl transferases and synthases use polyprenyl pyrophosphates as their natural substrates; however, it is known that free polyprenols, such as farnesol (FOH), and geranylgeraniol (GGOH) can be incorporated into prenylated proteins, ubiquinone, cholesterol, and dolichols. Furthermore, FOH and GGOH have been shown to block the effects of isoprenoid biosynthesis inhibitors such as fosmidomycin, bisphosphonates, or statins in several organisms. This phenomenon is the consequence of a short pathway, which was observed for the first time more than 25 years ago: the polyprenol salvage pathway, which works via the phosphorylation of FOH and GGOH. Biochemical studies in bacteria, animals, and plants suggest that this pathway can be carried out by two enzymes: a polyprenol kinase and a polyprenyl-phosphate kinase. However, to date, only a few genes have been unequivocally identified to encode these enzymes in photosynthetic organisms. Nevertheless, pieces of evidence for the importance of this pathway abound in studies related to infectious diseases, cancer, dyslipidemias, and nutrition, and to the mitigation of the secondary effects of several drugs. Furthermore, nowadays it is known that both FOH and GGOH can be incorporated via dietary sources that produce various biological effects. This review presents, in a simplified but comprehensive manner, the most important data on the FOH and GGOH salvage pathway, stressing its biomedical importance The main objective of this review is to bring to light the need to discover and characterize the kinases associated with the isoprenoid salvage pathway in animals and pathogens.

A new approach for analysis of polyprenols by a combination of thin-film chemical deposition and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

RATIONALE

The polyprenols are involved in some essential biosynthetic pathways and serve as ubiquitous components of cellular membranes, so their fingerprinting in natural samples is of great interest. Previous studies indicate that due to the high hydrophobicity of polyprenols their direct analysis by mass spectrometry with soft ionization techniques may be difficult and require preliminary off-line derivatization. Hence, a method for rapid and sensitive screening of polyprenols is required.

METHODS

A combination of thin-film chemical deposition and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was used for analysis of the polyprenol profile of Abies sibirica L. extract. Polyprenol-based monolayers were formed at the interphase of aqueous barium acetate solution, supplemented with 2,5-dihydroxybenzoic acid, and an n-hexane solution of polyprenols directly on a MALDI target plate.

RESULTS

Peaks corresponding to [M - H + Ba]⁺ ions were observed in the MALDI-TOF mass spectra of polyprenols. A total of nine polyprenol homologues were identified with a polyprenol of 16 isoprene units dominating. The limit of detection was established at the level of 6 pg. Possible mechanisms of formation of [M - H + Ba]⁺ ions of polyprenols were discussed.

CONCLUSIONS

The proposed approach can be suitable for high-throughput screening of polyprenols in biological samples of different origin due to easy sample preparation and high sensitivity.