Chromosome-level genome assembly and demographic history of Euryodendron excelsum in monotypic genus endemic to China

Euryodendron excelsum is in a monotypic genus Euryodendron, endemic to China. It has intermediate morphisms in the Pentaphylacaceae or Theaceae families, which make it distinct. Due to anthropogenic disturbance, E. excelsum is currently found in very restricted and fragmented areas with extremely small populations. Although much research and effort has been applied towards its conservation, its long-term survival mechanisms and evolutionary history remain elusive, especially from a genomic aspect. Therefore, using a combination of long/short whole genome sequencing, RNA sequencing reads, and Hi-C data, we assembled and annotated a high-quality genome for E. excelsum. The genome assembly of E. excelsum comprised 1,059,895,887 bp with 99.66% anchored into 23 pseudo-chromosomes and a 99.0% BUSCO completeness. Comparative genomic analysis revealed the expansion of terpenoid and flavonoid secondary metabolite genes, and displayed a tandem and/or proximal duplication framework of these genes. E. excelsum also displayed genes associated with growth, development, and defence adaptation from whole genome duplication. Demographic analysis indicated that its fluctuations in population size and its recent population decline were related to cold climate changes. The E. excelsum genome assembly provides a highly valuable resource for evolutionary and ecological research in the future, aiding its conservation, management, and restoration.

Three new glycosides from the stems of Eurya chinensis R. Br

Two new phenolic glycosides (1 and 2), one known analogue (3), along with a new diterpene glucoside (4) were obtained from ethanolic extract of the stems of Eurya chinensis R. Br. The structures of these isolated compounds were identified by extensive analysis of HRESIMS and NMR spectroscopic data. The cytotoxicities of these compounds were evaluated on MCF-7, A549, HepG2, CaCo2 and 5-8 F cell lines by MTT method, but no obvious activities were observed.

Chang (Pentaphylacaceae)

Eurya rubiginosa var. attenuata is a valuable multiuse tree with a long history of use in China. It has great economic and ecological importance and is used for landscape and urban planting, soil improvement, and raw materials for food production. However, genomic studies of E. rubiginosa var. attenuata are limited. Meanwhile, the classification of this taxon is controversial. In this study, the complete plastome of E. rubiginosa var. attenuata was successfully sequenced and assembled. The chloroplast genome is 157,215 bp in length with a 37.3% GC content. The chloroplast genome structure includes a quadripartite structure comprising a pair of inverted repeat (IR) sequences of 25,872 bp, a small single-copy (SSC) region of 18,216 bp, and a large single-copy (LSC) region of 87,255 bp. The genome contains 128 genes, including 83 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic inference based on complete plastome analysis showed that E. rubiginosa var. attenuata is closely related to E. alata and belongs to the family Pentaphylacaceae, which differs from the results of the traditional Engler system. The chloroplast genome sequence assembly and phylogenetic analysis enrich the genetic resources of Pentaphylacaceae and provide a molecular basis for further studies on the phylogeny of the family.

Ternstroenol F: a new pentacyclic triterpenoid saponin isolated from the Australian rainforest plant Ternstroemia cherryi

A detailed close phytochemical investigation of the fruits of Ternstroemia cherryi led to the isolation and identification of the minor metabolite, ternstroenol F, which possessed the usual barrigenol-like terpenoid backbone. The notable difference was that this minor metabolite had the 2(E)-4(Z)-6(E)-decatrienoic acid forming an ester bond at C-22 of the oleanane backbone. Ternstroenol F was evaluated for its inhibitory effects on NO inhibition, cell viability and TNF- α release in RAW 264.7 macrophages, displaying an IC₅₀ values of 0.23, 0.81 and 1.84 µM respectively.

The complete chloroplast genome of Eurya loquaiana (Pentaphylacaceae)

The complete chloroplast (cp) genome of Eurya loquaiana Dunn. has been reported in this study. The cp genome has a total length of 157,218 bp with the typical quadripartite structure, containing two inverted repeats (IRs) of 25,883 bp separated by a large single-copy (LSC) region of 87,248 bp and a small single-copy (SSC) region of 18,204 bp. The whole cp genome of E. loquaiana contains 128 genes, including 83 protein-coding genes, 37 tRNAs genes, and 8 rRNAs. The phylogenetic result showed that E. loquaiana is sister to E. alate.

Ternstroenols A - E: Undescribed pentacyclic triterpenoids from the Australian rainforest plant Ternstroemia cherryi

Chromatographic separation of the extracts of the Australian rainforest plant Ternstroemia cherryi led to the isolation of five undescribed barrigenol-like triterpenoids, ternstroenols A - E, from the fruits and three known ones from the leaves. Ternstroenols A - E represent a new form of structural diversity, being the first in its kind to incorporate a trans- 2, 4, 6- decatrienoyl moiety at C-22. The structures of the ternstroenols were assigned by detailed spectroscopic analysis, degradation and chemical derivatization. All compounds exhibited potent anti-inflammatory activity in LPS and IFN- γ activated RAW 264.7 macrophages, with IC₅₀ values as low as 0.7 μM. Despite the remarkable potency, high levels of unwanted cell growth inhibition was also observed, which prompted their cytotoxic evaluation in U87/U251 human glioblastoma cell lines.

Development and characterization of genomic SSR markers for Anneslea fragrans (Pentaphylacaceae)

PREMISE OF THE STUDY

The genus Anneslea (Pentaphylacaceae) contains four species and six varieties, most of which are locally endemic. Here, simple sequence repeat (SSR) markers were developed for the conservation of these species.

METHODS AND RESULTS

The genome of A. fragrans was sequenced and de novo assembled into 445,162 contigs, of which 30,409 SSR loci were detected. Primers for 100 SSR loci were validated with PCR amplification in three populations of A. fragrans. Seventy-nine loci successfully amplified, and 30 were polymorphic. The mean number of alleles, observed heterozygosity, and expected heterozygosity were 7.01 ± 1.60, 0.817 ± 0.241, and 0.796 ± 0.145, respectively. Most primers could be amplified in Ternstroemia gymnanthera, T. kwangtungensis, and Cleyerapachyphylla.

CONCLUSIONS

Our study demonstrated that shotgun genome sequencing is an efficient way to develop genomic SSR markers for nonmodel species. These genomic SSR loci will be valuable in population genetic studies in Anneslea and its relatives.