Development and analysis of de novo transcriptome assemblies of multiple genotypes of Cymbopogon spp. reveal candidate genes involved in the biosynthesis of aromatic monoterpenes.

Despite the high economic value of the monoterpene-rich essential oils from different genotypes of Cymbopogon, the knowledge about the genes and metabolic route(s) involved in the biosynthesis of aromatic monoterpenes in this genus is limited. In the present study, a comprehensive transcriptome analysis of four genotypes of Cymbopogon, displaying diverse quantitative and qualitative profiles of volatile monoterpenes in their essential oils has been carried out. The comparative analysis of the deduced protein sequences corresponding to the transcriptomes of the four genotypes revealed 4609 genotype-specific orthogroups, which might contribute in defining genotype-specific phenotypes. The transcriptome data mining led to the identification of unigenes involved in the isoprenogenesis. The homology searches, combined with the phylogenetic and expression analyses provided information about candidate genes concerning the biosynthesis of monoterpene aldehyde, monoterpene alcohol, and monoterpene esters. In addition, the present study suggests a potential role of geranial reductase like enzyme in the biosynthesis of monoterpene aldehyde in Cymbopogon spp. The detailed analysis of the candidate pathway genes suggested that multiple enzymatic routes might be involved in the biosynthesis of aromatic monoterpenes in the genus Cymbopogon. The present study provides deeper insights into the biosynthesis of monoterpenes, which will be useful for the genetic improvement of these aromatic grasses.

Facile Synthesis of Benzimidazoles via Oxidative Cyclization of Acyclic Monoterpene Aldehyde with Diamines: Studies on Antimicrobial and in Vivo Evaluation of Zebrafish.

Citral (1a), a bioactive component of Cymbopogon citratus (lemongrass) could be isolated and semi-synthetic analogs synthesized with improved therapeutic properties. Herein we first report describes citral (1a) as a primary material for the synthesis of benzimidazole derivatives between various o-phenylenediamines (2a-l) in the presence of Diisopropylethylamine (DIPEA) as a commercially available environmentally benign base, ethanol as a green solvent and the yield of all benzimidazole derivatives (3a-l) was between 68-76 %; The semi-synthetically prepared benzimidazole derivatives (3a-l) were assessed for their anti-bacterial and anti-fungal properties. The benzimidazole compounds (3a-b, and 3g-j) exhibit good anti-microbial activity. In addition, in silico study was carried out to determine the specific binding affinity of the diamine halogen substituted benzimidazole derivatives to the specific target proteins. In silico analysis revealed a high correlation between docking results and experimental results. Finally, benzimidazole demonstrated significant antibacterial and antifungal activity. Zebrafish embryos were subjected to In vivo toxicological test found that all of the benzimidazole compounds (3a-l) were non-toxic and had low embryotoxicity after 96 h, with an LC50 of 36.425 µg, which could facilitate the design of novel antimicrobial agents using a cost-effective method.

Pulegone: An Emerging Oxygenated Cyclic Monoterpene Ketone Scaffold Delineating Synthesis, Chemical Reactivity, and Biological potential.

Pulegone ((R)-5-Methyl-2-(1-methylethylidine) cyclohexanone) is a pharmacologically active, natural monoterpene ketone obtained from leaves and flowering tops of the mint family (Lamiaceae). The aim is to comprise the physicochemical and biological aspects of pulegone. All significant databases were collected via electronic search using Pubmed, Scopus, Web of Science, and Science Direct and were compiled. This review presents the occurrence, chemistry, and modifications of pulegone structure and its effect on the biological system. Pulegone represents various pharmacological properties, i.e., antioxidant, antimicrobial, anti-feeding, antifungal, antiviral, and pesticide activities, and has a significant role as an abortifacient and emmenagogue. Thus, this present review concludes the knowledgeable erudition on pulegone that paves the way for further work.