1.Sesquiterpenoids with PTP1B Inhibitory Activity and Cytotoxicity from the Edible Mushroom Pleurotus citrinopileatus.
Tao QQ1, Ma K1, Bao L1, Wang K1, Han JJ1, Wang WZ1, Zhang JX2, Huang CY2, Liu HW1. Planta Med. 2016 Feb 12. [Epub ahead of print]
One new perhydrobenzannulated 5,5-spiroketal sesquiterpene, pleurospiroketal F (1), as well as six new modified bisabolene sesquiterpenes pleurotins A-F (2-7) were isolated from solid-state fermentation of Pleurotus citrinopileatus. The structures of compounds 1-7 were determined by NMR and MS spectroscopic analysis. The absolute configuration of 1 was determined by X-ray diffraction analysis, while the absolute configurations of 3-7 were assigned using the in situ dimolybdenum circular dichroism method and circular dichroism data comparison. Protein tyrosine phosphatase 1B plays a crucial role as a negative regulator of the insulin-dependent signal cascades. Therefore, the protein tyrosine phosphatase 1B inhibitor can be used for treating type 2 diabetes mellitus and obesity. Compounds 2 and 6 showed moderate inhibitory effects on protein tyrosine phosphatase 1B with IC50 s of 32.1 µM and 30.5 µM, respectively. The kinetic study confirmed compound 2 to be a noncompetitive inhibitor.
2.Identification and characterization of two bisabolene synthases from linear glandular trichomes of sunflower (Helianthus annuus L., Asteraceae).
Aschenbrenner AK1, Kwon M2, Conrad J3, Ro DK2, Spring O4. Phytochemistry. 2016 Apr;124:29-37. doi: 10.1016/j.phytochem.2016.01.009. Epub 2016 Feb 12.
Sunflower is known to produce a variety of bisabolene-type sesquiterpenes and accumulates these substances in trichomes of leaves, stems and flowering parts. A bioinformatics approach was used to identify the enzyme responsible for the initial step in the biosynthesis of these compounds from its precursor farnesyl pyrophosphate. Based on sequence similarity with a known bisabolene synthases from Arabidopsis thaliana AtTPS12, candidate genes of Helianthus were searched in EST-database and used to design specific primers. PCR experiments identified two candidates in the RNA pool of linear glandular trichomes of sunflower. Their sequences contained the typical motifs of sesquiterpene synthases and their expression in yeast functionally characterized them as bisabolene synthases. Spectroscopic analysis identified the stereochemistry of the product of both enzymes as (Z)-γ-bisabolene. The origin of the two sunflower bisabolene synthase genes from the transcripts of linear trichomes indicates that they may be involved in the synthesis of sesquiterpenes produced in these trichomes.
3.Chemical composition of the essential oil from the leaves of Anaxagorea brevipes (Annonaceae) and evaluation of its bioactivity.
de Alencar DC1, Pinheiro ML1, Pereira JL1, de Carvalho JE2, Campos FR3, Serain AF4, Tirico RB4, Hernández-Tasco AJ4, Costa EV1, Salvador MJ4. Nat Prod Res. 2016 May;30(9):1088-92. doi: 10.1080/14786419.2015.1101103. Epub 2015 Nov 19.
The essential oil obtained by hydrodistillation from leaves of Anaxagorea brevipes was analysed by gas chromatography fitted with a flame ionisation detector (GC-FID) and coupled to mass spectrometry (GC-MS). Thirty one components were identified, representing around 75.7% of total oil. The major components were β-eudesmol (13.16%), α-eudesmol (13.05%), γ-eudesmol (7.54%), guaiol (5.12%), caryophyllene oxide (4.18%) and β-bisabolene (4.10%). The essential oil showed antimicrobial activity against Gram-positive bacteria and yeast with the MIC values between 25.0 and 100 μg/mL. The highest antiproliferative activity was observed for the oil against MCF-7 (breast, TGI = 12.8 μg/mL), NCI-H460 (lung, TGI = 13.0 μg/mL) and PC-3 (prostate, TGI = 9.6 μg/mL) cell lines, while against no cancer cell line HaCat (keratinocyte) the TGI was 38.8 μg/mL. The oil exhibited a small antioxidant activity assessed through ORAC-FL assay (517 μmol TE/g). This is the first report regarding the chemical composition and bioactivity of A.
4.Rapid Discovery and Functional Characterization of Terpene Synthases from Four Endophytic Xylariaceae.
Wu W1, Tran W1, Taatjes CA2, Alonso-Gutierrez J3,4, Lee TS3,4, Gladden JM1,4. PLoS One. 2016 Feb 17;11(2):e0146983. doi: 10.1371/journal.pone.0146983. eCollection 2016.
Endophytic fungi are ubiquitous plant endosymbionts that establish complex and poorly understood relationships with their host organisms. Many endophytic fungi are known to produce a wide spectrum of volatile organic compounds (VOCs) with potential energy applications, which have been described as "mycodiesel". Many of these mycodiesel hydrocarbons are terpenes, a chemically diverse class of compounds produced by many plants, fungi, and bacteria. Due to their high energy densities, terpenes, such as pinene and bisabolene, are actively being investigated as potential "drop-in" biofuels for replacing diesel and aviation fuel. In this study, we rapidly discovered and characterized 26 terpene synthases (TPSs) derived from four endophytic fungi known to produce mycodiesel hydrocarbons. The TPS genes were expressed in an E. coli strain harboring a heterologous mevalonate pathway designed to enhance terpene production, and their product profiles were determined using Solid Phase Micro-Extraction (SPME) and GC-MS.