Chemical and genomic diversity of six Lonicera species occurring in Korea

Quality Evaluation of Lonicerae Flos Produced in Southwest China Based on HPLC Analysis and Antioxidant Activity

Lonicera macranthoides, the main source of traditional Chinese medicine Lonicerae Flos, is extensively cultivated in Southwest China. However, the quality of L. macranthoides produced in this region significantly varies due to its wide distribution and various cultivation breeds. Herein, 50 Lonicerae Flos samples derived from different breeds of L. macranthoides cultivated in Southwest China were collected for quality evaluation. Six organic acids and three saponin compounds were quantitatively analyzed using HPLC. Furthermore, the antioxidant activity of a portion of samples was conducted with 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging experiments. According to the quantitative results, all samples met the quality standards outlined in the Chinese Pharmacopoeia. The samples from Guizhou, whether derived from unopened or open wild-type breeds, exhibited high quality, while the wild-type samples showed relatively significant fluctuation in quality. The samples from Chongqing and Hunan demonstrated similar quality, whereas those from Sichuan exhibited relatively lower quality. These samples demonstrated significant abilities in clearing ABTS and DPPH radicals. The relationship between HPLC chromatograms and antioxidant activity, as elucidated by multivariate analysis, indicated that chlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, and isochlorogenic acid C are active components and can serve as Q-markers for quality evaluation.

Complete chloroplast genome and phylogenetic analysis of Lonicera caerulea var. edulis (Caprifoliaceae)

Lonicera caerulea var. edulis, known as "blue honeysuckle" or "Haskap," is a deciduous shrub that belongs to the Caprifoliaceae family. Characterized by the high cold hardiness and high quality of fruit, it has become a novel cash crop in cold regions worldwide. The lack of available chloroplast (cp) genome information limits studies of its molecular breeding and phylogeny. Here, the complete cp genome of Lonicera caerulea var. edulis was assembled and characterized for the first time. It was 155,142 bp in length with 38.43% of GC content, including 23,841 bp inverted repeat regions (IRs), an 88,737 bp large single-copy region (LSC), and an 18,723 bp small single-copy region (SSC). A total of 132 genes, including 85 protein-coding genes, 8 rRNA genes, and 39 tRNA genes were annotated. Phylogenetic analysis indicated that L. caerulea var. edulis was closely related to L. tangutica. These data and results provide a valuable resource for the development of breeding tools and genetic diversity studies for L. caerulea.

Complete plastome sequence of Lonicera gynochlamydea Hemsl. (Caprifoliaceae)

We report and characterize the complete plastome of Lonicera gynochlamydea Hemsl. L. gynochlamydea is a shrub, belonging to the family Caprifoliaceae. Our results show that the length of the complete plastome is 154,643 bp, including 131 genes consisting of 84 protein-coding genes, 39 tRNA genes, and eight rRNA genes. The plastome exhibits the typical quadripartite structure and gene content of angiosperms, composed of two inverted repeats (IRs) regions of 23,846 bp, a large single-copy (LSC) region of 88,298 bp, and a small single-copy (SSC) region of 18,653 bp. The total G/C content in L. gynochlamydea plastome is 38.4%. The complete plastome sequence of L. gynochlamydea will make contributions to the conservation genetics of this species as well as to phylogenetic studies in Caprifoliaceae.

Assessing the genetic and chemical diversity of Taraxacum species in the Korean Peninsula

The genetic relationship between Taraxacum species, also known as the dandelion, is complicated because of asexual and mixed sexual apomictic reproduction. The usage of Taraxacum species in traditional medicines make their specialized metabolism important, but interspecific chemical difference has rarely been reported for the genus. In this study, we assembled the chloroplast genome and 45S rDNA of six Taraxacum species that occur in Korea (T. campylodes, T. coreanum, T. erythrospermum, T. mongolicum, T. platycarpum, and T. ussuriense), and performed a comparative analysis, which revealed their phylogenetic relationships and possible natural hybridity. We also performed a liquid chromatography-mass spectrometry-based phytochemical analysis to reveal interspecific chemical diversity. The comparative metabolomics analysis revealed that Taraxacum species could be separated into three chemotypes according to their major defensive specialized metabolites, which were the sesquiterpene lactones, the phenolic inositols, and chlorogenic acid derivatives. The CP DNA- and 45S rDNA-based phylogenetic trees showed a tangled relationship, which supports the notion of ongoing hybridization of wild Taraxacum species. The untargeted LC-MS analysis revealed that each Taraxacum plant exhibits species-specific defensive specialized metabolism. Moreover, 45S rDNA-based phylogenetic tree correlated with the hierarchical cluster relied on metabolite compositions. Given the coincidence between these analyses, we represented that 45S rDNA could well reflect overall nuclear genome variation in Taraxacum species.

Assessing specialized metabolite diversity of Alnus species by a digitized LC-MS/MS data analysis workflow

Alnus spp. (Betulaceae) have been used for treatments of hemorrhage, burn injuries, antipyretic fever, diarrhea, and alcoholism in traditional medicines. In this study, a digitized LC-MS/MS data analysis workflow was applied to provide an overview on chemical diversity of 15 Alnus extracts prepared from bark, twigs, leaves, and fruits of A. japonica, A. firma, A. hirsuta, and A. hirsuta var. sibirica. Most of the MS/MS spectra could be putatively annotated based on library matching, in silico fragmentation, and substructural topic modeling. The putative annotation allowed us to discriminate the extracts into three chemotypes based on dominant chemical scaffolds: diarylheptanoids, flavonoids or tannins. This high-throughput chemical annotation was correlated with α-glucosidase inhibition data of extracts, and it allowed us to identify gallic acid as the major active compound of A. firma.