A new pregnanone, named calotropone (1), was isolated from the EtOH extract of the roots of Calotropis gigantea L. together with a known cardiac glycoside. The structures were elucidated by a study of their physical and spectral data. Compounds 1 and 2 displayed inhibitory effects towards chronic myelogenous leukemia K562 and human gastric cancer SGC-7901 cell lines.

Cephalotaxus hainanensis, an endangered plant, is known to contain several metabolites with anti-cancer activity. Despite its clinical impact, the alkaloid metabolism of this species has remained largely uncharacterized. The potential of Cephalotaxus for metabolic engineering of medically interesting compounds has, so far, not been exploited, due to the almost complete lack of molecular information. We have therefore performed a high throughput RNA-seq analysis and assembled the transcriptome de novo. Raw reads comprising 4.3 Gbp were assembled de novo into 39,416 unique sequences (unigenes) with a mean length of 1,089.8 bp and a total assembly size of 45.8 Mbp, which equals to more than 50 times the number of Cephalotaxaceae sequences currently deposited in the GenBank (as of August 2013). As proof of principle for medically interesting pathways, gene fragments related to paclitaxel biosynthesis were searched and detected. To verify their functionality, the metabolic product paclitaxel, and its precursor baccatin III, were identified in the leaves of C. hainanensis by HPLC, and shown to be induced by MeJA. This finding demonstrates exemplarily the potential of the annotated transcriptome as information resource for the biotechnological exploitation of plant secondary metabolism.

Roots of Morinda officinalis and Morinda citrifolia have been interchangeably used in traditional Chinese medicine. However, there is no experimental evidence to support this. In this study, a ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS)-based approach and a multivariate statistical analysis (MSA) were adopted to compare the difference in the chemical compounds present in the root extract of M. officinalis and M. citrifolia. There were 26 anthraquinones, 15 triterpenes, and 8 iridoid glycosides identified in the root extracts of M. officinalis, 30 anthraquinones, 1 triterpene, and 8 iridoid glycosides in the root extracts of M. citrifolia. Among these, 25 compounds presented in both plants. In addition, a principal component analysis (PCA) showed that these two herbs could be separated clearly. Furthermore, an orthogonal partial least squares-discriminant analysis (OPLS-DA) found 9 components that could be used as chemical markers to discrimination the root extracts of M. officinalis and M. citrifolia. In addition, the results of a Cell Counting Kit 8 (CCK-8) assay and cell colony formation assay indicated that methanol root extracts of M. officinalis and M. citrifolia showed no cell cytotoxicity to normal cells, even promoted the proliferation of normal liver cells. To our knowledge, this is the first time that the differences between the root extracts of M. officinalis and M. citrifolia (Hainan province) have been observed systematically at the chemistry level.

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Callerya speciosa (Champ.) ScHot is a woody perennial plant in Fabaceae, the roots of which are used medicinally. The storage roots of C. speciosa are derived from fibrous roots, but not all fibrous roots can develop into storage roots. To detect key genes involved in storage roots formation, we performed Illumina sequencing of the C. speciosa storage roots and fibrous roots. De novo assembly resulted in 161,926 unigenes, which were subsequently annotated by BLAST, GO and KEGG analyses. After expression profiling, 4538 differentially expressed genes were identified. The KEGG pathway enrichment analysis revealed changes in the biosynthesis of cytokinin, phenylpropanoid, starch, sucrose, flavone and other secondary metabolites. Transcription factor-related differentially expressed genes (DEGs) were also identified, including such gene families as GRAS, COL, MIKC, ERF, LBD, and NAC. The DEGs related to light signaling, starch, sugar, photohormones and cell wall-loosening might be involved in the formation of storage roots. This study provides the first transcriptome profiling of C. speciosa roots, data that will facilitate future research of root development and metabolites with medicinal value as well as the breeding of C. speciosa.

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Membrane bound O-acyl transferase (MBOAT) family is composed of gene members encoding a variety of acyltransferase enzymes, which play important roles in plant acyl lipid metabolism. Here, we present the first genome-enabled identification and analysis of MBOAT gene models in plants. In total, we identified 136 plant MBOAT sequences from 14 plant species with complete genomes. Phylogenetic relationship analyses suggested the plant MBOAT gene models fell into four major groups, two of which likely encode enzymes of diacylglycerol acyltransferase 1 (DGAT1) and lysophospholipid acyltransferase (LPLAT), respectively, with one-three copies of paralogs present in each of the most plant species. A group of gene sequences, which are homologous to Saccharomyces cerevisiae glycerol uptake proteins (GUP), was identified in plants; copy numbers were conserved, with only one copy represented in each of the most plant species; analyses showed that residues essential for acyltransferases were more prone to be conserved than vertebrate orthologs. Among four groups, one was inferred to emerge in land plants and experience a rapid expansion in genomes of angiosperms, which suggested their important roles in adaptation of plants in lands. Sequence and phylogeny analyses indicated that genes in all four groups encode enzymes with acyltransferases. Comprehensive sequence identification of MBOAT family members and investigation into classification provide a complete picture of the MBOAT gene family in plants, and could shed light into enzymatic functions of different MBOAT genes in plants.