ABSTRACT
Objective: To explore the active constituents from the stems of Orostachys malacophyllus in Changbai Mountain. Methods: The ethyl acetate fraction of the methanol extract from the stems of O. malacophyllus was separated by chromatographic methods, structure identification was by means of nuclear magnetic resonance and mass spectra, and the activity was determined by CCK-8 experiment. Results: Five compounds were isolated and identified as 1-ethyl-2-hydroxysuccinate (1), 1-ethyl-2-O-[(3,4-dihydroxybenzoyl) oxy]-succinate (2), 1,4-dimethy-2-O-[(3,4-dihydroxybenzoyl) oxy]-succinate (3), 1,4-dimethy-2-O-[(4-dihydroxybenzoyl) oxy]-succinate (4), and diisobutyl phthalate (5). Conclusion: Compounds 1-5 are isolated from the plants of this genus for the first time. Among them, compound 2 is a new compound named orostachysolic acid, and exhibits cytotoxicity against HeLa cell with IC50 value of 111.5 μmol/L.
ABSTRACT
Squalene synthase (SQS) is a key enzyme in plant terpenoid biosynthetic pathway. This study focused on cloning and analysis of Huperzia serrata SQS (HsSQS1) gene. After searching the transcriptome dataset of H serrata, one unique sequence encoding SQS was discovered. The primers were designed according to the transcript sequence of HsSQS1 from the H. serrata transcriptome dataset. The open reading frame of HsSQS1 was cloned using RT-PCR strategy. The bioinformatic analysis of this gene and its corresponding protein were performed. The cDNA (named as HsSQS1) contains a 1263 bp open reading frame and encodes a predicted protein of 420 amino acids. The GenBank accession number for this gene is JQ004938. HsSQS1 contains two transmembrane regions, without signal peptide. The conserved domain of squalene synthase was presented in HsSQS1. HsSQS1 was more abundant in H. serrata root than in leaf and stem. This study cloned and analyzed squalene synthase gene from H. serrata for the first time. The result will provide a foundation for exploring the mechanism ofterpenoid biosynthesis in H. serrata plants.