Reversed-phase high-performance Liquid Chromatography-ultraviolet Photodiode Array Detector Validated Simultaneous Quantification of six Bioactive Phenolic Acids in Roscoea purpurea Tubers and their In vitro Cytotoxic Potential against Various Cell Lines

In-depth phytochemical profiling of Roscoea purpurea (Kakoli): Comparative UHPLC-MS/QToF and GC-MS/MS analysis of supercritical CO2 fluid - and conventional solvent - based extractive processes

The remarkable biodiversity of medicinal plants worldwide highlights their significance in traditional and alternative medicine. Astavarga, a group of eight medicinal herbs from the Himalayan region of India, including Roscoea purpurea (commonly known as Kakoli), is esteemed in Ayurveda for its health-promoting and rejuvenating properties. In this comprehensive study, we aimed to develop and optimise robust UHPLC-MS/QToF (Ultra-high-performance liquid chromatography-mass spectrometry coupled with quadrupole time of flight) and GC-MS/MS (Gas chromatography-tandem mass spectrometry) methods to identify the phytochemicals in R. purpurea root hydromethanolic extract and essential oil. We also conducted a comparative assessment of supercritical fluid extraction and conventional solvent extraction methods for the first time in R. purpurea root, highlighting their relevance to the medicinal field. Using the UHPLC/MS-QToF method, we identified a total of fifty-six phytometabolites, while sixteen volatile constituents were discerned within the essential oil of R. purpurea by GC-MS/MS method. Among the volatile constituents, β-eudesmol (40.84 %), guaiac acetate (10.55 %), and γ-eudesmol (10.31 %) were emerged as the principal components. Our findings were further compared with the volatile constituents extracted via supercritical fluid extraction and conventional solvent extraction methods. Notably, our research unveiled the presence of a carotenoid metabolite, 15-methyl retinol, for the first time. Furthermore, our fatty acid analysis of the supercritical fluid extract revealed elevated levels of unsaturated fatty acids, particularly oleic and linoleic acids. The methods were validated in terms of system specificity also. The discovery of these well-recognised therapeutically active components in R. purpurea significantly enhances its potential, highlighting its unique profile among medicinal plants in the Himalayan region and its suitability for traditional Ayurveda.

Draft genome of Roscoea Debilis, the first genome in the alpine ginger Roscoea (Zingiberaceae)

OBJECTIVES

Roscoea is a Sino-Himalayan alpine genus in pantropical family Zingiberaeae. As traditional Tibetan medicinal plants, many species of this genus are threatened by digging, logging, land clearance, grazing and climate change. Roscoea debilis is an endemic species in the Hengduan Mountains with a narrow distribution range. In this study, the assembled and annotated genome of Roscoea was presented in order to furnish significant resources for comparative and functional genomic investigations. The first complete reference genome of Roscoea is expected to shed light on research on conservation and evolutionary biology.

DATA DESCRIPTION

A chromosome-level genome of 1601.04 Mb was obtained for R. debilis by combining Illumina short reads (107.28 Gb) and PacBio Hi-Fi reads (64.08 Gb), achieving high-quality sequencing coverage of roughly 67 × and 40 ×. The assembly was additionally assisted by 271.65 Gb Hi-C data (169 ×), which resulted in a contig N50 of 136.17 Mb and a scaffold N50 of 90.48 Mb. Benchmarking Universal Single-Copy Orthologs (BUSCO) assessment results revealed that most of the core embryophyta genes (98.7%) in the BUSCO dataset (embryophyta_odb10) were successfully identified. Additionally, 96.44% of the genomic sequences were accurately mapped onto twelve pseudochromosomes.

Plastid phylogenomics and species discrimination in the "Chinese" clade of Roscoea (Zingiberaceae)

Roscoea is an alpine or subalpine genus from the pan-tropical family Zingiberaceae, which consists of two disjunct groups in geography, namely the "Chinese" clade and the "Himalayan" clade. Despite extensive research on the genus, Roscoea species remain poorly defined and relationships between these species are not well resolved. In this study, we used plastid genomes of nine species and one variety to resolve phylogenetic relationships within the "Chinese" clade of Roscoea and as DNA super barcodes for species discrimination. We found that Roscoea plastid genomes ranged in length from 163,063 to 163,796 bp, and encoded 113 genes, including 79 protein-coding genes, 30 tRNA genes, four rRNA genes. In addition, expansion and contraction of the IR regions showed obvious infraspecific conservatism and interspecific differentiation. Plastid phylogenomics revealed that species belonging to the "Chinese" clade of Roscoea can be divided into four distinct subclades. Furthermore, our analysis supported the independence of R. cautleoides var. pubescens, the recovery of Roscoea pubescens Z.Y. Zhu, and a close relationship between R. humeana and R. cautloides. When we used the plastid genome as a super barcode, we found that it possessed strong discriminatory power (90%) with high support values. Intergenic regions provided similar resolution, which was much better than that of protein-coding regions, hypervariable regions, and DNA universal barcodes. However, plastid genomes could not completely resolve Roscoea phylogeny or definitively discriminate species. These limitations are likely related to the complex history of Roscoea speciation, poorly defined species within the genus, and the maternal inheritance of plastid genomes.

Coronarin K and L: Two Novel Labdane Diterpenes From Roscoea purpurea: An Ayurvedic Crude Drug

The main objective of cancer treatment with chemotherapy is to kill the cancerous cells without affecting the healthy normal cells. In the present study, bioactivity-guided purification of the n-chloroform soluble fraction from the methanol extract of Roscoea purpurea resulted in the identification of two new labdane diterpenes: coronarin K (1) and coronarin L (2), along with eight known compounds, coronarin A (3), bisdemethoxycurcumin (4), kaempferol 3-O-methyl ether (5), kaempferol (6), fenozan acid (7), 3-(3-methoxy,4-hydroxyphenyl)-2-propenoic acid ferulic acid (8), caffeic acid (9), and gallic acid (10). The structural identification of new compounds (1 and 2) were determined by detailed analysis of 1D (¹H and ¹³C) and 2D NMR (COSY, HSQC, and HMBC) spectroscopic data. The relative configurations of 1 and 2 were determined with the help of NOESY correlations and comparison of optical rotations with known labdane diterpenes, with established stereochemistry, while structure of known compounds was established by direct comparison of their NMR data with those reported in the literature. This is the first report of isolation of this labdane diterpenes and phenolic classes of secondary metabolites in R. purpurea. In the preliminary screening, the methanol extract and its fractions were tested for the cytotoxic activity against a panel of four cancer cell lines (A549, HCT-116, Bxpc-3, and MCF-7); extract and its chloroform fraction were found to be active against the lung cancer cell line, A-549, with IC₅₀ value <25 μg/ml. Owing to the notable cytotoxic activity of the chloroform fraction, the compounds (1-5) were screened for their cytotoxicity against all the cell lines by MTT assay. Coronarin K, 1 showed significant cytotoxic potential against lung cancer cell lines (A-549), with IC₅₀ value of 13.49 μM, while other compounds did not show activity below 22 μM.