ABSTRACT
Schisandra chinensis Turcz. (Baill.) is a plant species with fruits that have been well known in Far Eastern medicine for a long time. It has traditionally been used as a stimulating and fortifying agent in cases of physical exhaustion and to inhibit fatigue. The major bioactive compounds found in S. chinensis are lignans with a dibenzocyclooctadiene skeleton, but little is known about their biosynthesis in plants. S. chinensis is the ideal medicinal plant for studying the biosynthesis of lignans, especially the dibenzocyclooctadiene skeleton. Genomic information for this important herbal plant is unavailable. To better understand the lignan biosynthesis pathway, we generated transcriptome sequences from the fruit during ripening and performed de novo sequence assembly, yielding 136 843 unique transcripts with N50 of 1778 bp. Putative functions could be assigned to 41 824 transcripts (51.57%) based on BLAST searches against annotation databases including GO (Gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes). Furthermore, 22 candidate cytochrome P450 genes and 15 candidate dirigent proteins genes that were most likely involved in the lignan biosynthesis pathway were discovered based on transcriptome sequencing of S. chinensis. The genomic data obtained from S. chinensis, especially the identification of putative genes involved in the lignan biosynthesis pathway, will facilitate our understanding of lignan biosynthesis at the molecular level. The lignan metabolite profiles were analyzed by metabolomes, the accumulation patterns of 30 metabolites involved in the lignan pathway were studied. Co-expression network of lignan contents and transcriptional changes showed 355 strong correlations (correlation coefficient, R > 0.9) between 21 compounds and 153 transcripts. Furthermore, the comprehensive analysis and characterization of the genes involved in lignan pathways and the metabolite profiles of lignans are expected to provide better insight regarding the diversity of the chemical composition, synthetic characteristics, and regulatory mechanisms of this medical herb.
ABSTRACT
2-(2-Phenylethyl) chromones are only distributed in a few plant species and have many bioactivities such as neuroprotection, antibacterial and anti-inflammatory effects. They are the characteristic and main active components of agarwood. They are expected to have broad medicinal application value. In this paper, the research progress of the biological activities such as neuroprotective activity, anti-tumor cytotoxic activity, antibacterial activity and anti-inflammatory activity, as well as the structure-activity relationship and biosynthetic pathway of 2-(2-phenethyl) chromone compounds were reviewed and prospected. It provides a reference for screening the pharmaceutical 2-(2-phenethyl) chromone compounds and analyzing their biosynthetic pathways. Some problems in the current biosynthesis researches are also pointed out here.
ABSTRACT
Rauvolfia serpentine is a traditional Indian medicine and now the genus Rauvolfia becomes a commonly used south medicine in China. Rauvolfia is mainly used to treat hypertension, mental illness, cardiovascular disorders, cancer, and other diseases. The paper overviewed the main species and distribution, pharmacological properties, and the monoterpenoid indole alkaloids biosynthetic pathway of Rauvolfia in China. The paper aims to provide reference for research and clinical application in plants of the genus Rauvolfia.
ABSTRACT
Anemone flaccida Fr. Schmidt is a perennial medicinal herb that contains pentacyclic triterpenoid saponins as the major bioactive constituents. In China, the rhizomes are used as treatments for a variety of ailments including arthritis. However, yields of the saponins are low, and little is known about the plant's genetic background or phytohormonal responsiveness. Using one-quarter of the 454 pyrosequencing information from the Roche GS FLX Titanium platform, we performed a transcriptomic analysis to identify 157 genes putatively encoding 26 enzymes involved in the synthesis of the bioactive compounds. It was revealed that there are two biosynthetic pathways of triterpene saponins in A. flaccida. One pathway depends on β-amyrin synthase and is similar to that found in other plants. The second, subsidiary ("backburner") pathway is catalyzed by camelliol C synthase and yields β-amyrin as minor byproduct. Both pathways used cytochrome P450-dependent monooxygenases (CYPs) and family 1 uridine diphosphate glycosyltransferases (UGTs) to modify the triterpenoid backbone. The expression of CYPs and UGTs were quite different in roots treated with the phytohormones methyl jasmonate, salicylic acid and indole-3-acetic acid. This study provides the first large-scale transcriptional dataset for the biosynthetic pathways of triterpene saponins and their phytohormonal responsiveness in the genus Anemone.
Subject(s)
Anemone , Genetics , Metabolism , Biosynthetic Pathways , Genetics , Cytochrome P-450 Enzyme System , Genetics , Metabolism , Gene Expression Profiling , Gene Expression Regulation, Plant , Glycosyltransferases , Genetics , Metabolism , Oleanolic Acid , Metabolism , Plant Growth Regulators , Pharmacology , Plant Proteins , Genetics , Metabolism , Plants, Medicinal , Rhizome , Genetics , Metabolism , Saponins , Metabolism , Triterpenes , MetabolismABSTRACT
Aporphine alkaloids belong to isoquinoline alkaloids and have a wide range of physiological activities. These natural products and their derivatives are the lead compound of the novel drug for the treatment of various diseases. Based on many literatures, the plant distribution, biosynthetic pathways, natural organic synthesis methods and pharmacological activities of those aporphine alkaloids have been summarized in this paper, which would supported the deeply development about the pharmaceutical research based on the aporphine alkaloids.
ABSTRACT
This study aimed to provide guidance for the heterogenous gene expression, gene prediction and species evolution by analyzing codon usage bias of Catharanthus roseus.The codon composition and usage bias of 30 437 high-confidence coding sequences from C.roseus were analyzed and the proportion of rare codons of Escherichia coli and Saccharomyces cerevisiae in 25 genes involved in the biosynthesis of terpenoid indole alkaloids (TIAs) in C.roseus were calculated.The results showed that the average GC content of the genes was 42.47%; the average GC content of the third bases in codon was 35.89%.The relative synonymous codon usage (RSCU) of 28 codons were greater than 1 and 26 of them ended with A or T.The above 25 genes involved in TIA biosynthesis contained much more rare condons of E.coli than that of S.cerevisiae.It was concluded that C.roseus mainly prefered the codons ending with A or T and the rule of codon usage was more different to E.coli than S.cerevisiae.Thus, S.cerevisiae may be more suitable host for heterologous expression of these genes.
ABSTRACT
Exosomes are small vesicular bodies of 40-100 nm secreted by various types of living cells into the extracellular environment, and contain proteins, lipids and nucleic acids. Gastrointestinal tumor is one of the most common malignant tumor. The morbidity and mortality of gastric cancer, pancreatic cancer and colorectal cancer are high among malignant tumors. As a hotspot in the research of oncology, exosomes have potential values in the research of development, diagnosis and treatment of human gastrointestinal tumor. This review summarizes the biogenesis and components of exosomes as well as the progression of exosomes in human gastrointestinal tumor.