ABSTRACT
Objective: To study the chemcial constituents from Melicope ptelefolia. Methods: The constituents were isolated and purified by chromatography with silica gel, Sephadex LH-20, and recrystallization. The structures were elucidated by sepectroscopic anaylsis (NMR and ESI-MS). Results: Twelve compounds were isolated from petroleum ether and ethyl acetate soluble fraction and identified as: physcion (1), stigmata-3,5-dien-7-one (2), β-sitostenone (3), 24(R)-24-ethyl-5α-cholestane-3β,5α,6β-triol (4), dihydroxanthyletin (5), methyl icosanoate (6), emodin (7), (+)-marmesin (8), rudicoumarin C (9), 3-(2',3'-dihydroxy) isopentyl-7- hydroxycoumarin (10), and 4-methoxy-2(1H)-quinolinone (11). Conclusion: Compounds 1-11 are isolated from M. ptelefolia for the first time. Compound 10 is a new compound named pteleifolosin D.
ABSTRACT
Objective: To study the full-length gene structure characteristics and coding protein properties of 3-hydroxy-3-methyl-glutaryl-CoA reductase (BpHMGR) from Betula platyphylla (birch). This reveals the mechanism of rhythm expression pattern and its signaling molecule in response to exogenous NO. Methods: The BpHMGR gene in birch was cloned by RACE technology. BpHMGR and its encoded protein were analyzed in detail by bioinformatics software. And the expression pattern in the circadian variation of BpHMGR gene was analyzed by real-time PCR. Results: The full-length of BpHMGR gene was 1764 bp, contained the complete ORF, encoding 587 amino acids (Genebank ID: KJ197336). According to BpHMGR amino acid sequence, phylogenetic tree was constructed. And the effect of circadian rhythm and exogenous NO on the transcription level of BpHMGR in the leaves of B. platyphylla was investigated. Conclusion: BpHMGR gene, soybean (XP_003519474.1), grape (XP_002275827.1), and alfalfa (XP_003617066.1) have close genetic relationship. BpHMGR changes with the diurnal cycle showing the expression characteristics of rhythm, and reaches the peak at 9 pm. The up-regulation expression of key enzyme gene HMGR in the exogenous NO-induced birch intracellular triterpenoids metabolic pathway is initially revealed, so as to promote the synthesis of triterpene oleanolic acid product.