Heterologous expression of cytotoxic sesquiterpenoids from the medicinal mushroom Lignosus rhinocerotis in yeast

Background: Genome mining facilitated by heterologous systems is an emerging approach to access the chemical diversity encoded in basidiomycete genomes. In this study, three sesquiterpene synthase genes, GME3634, GME3638, and GME9210, which were highly expressed in the sclerotium of the medicinal mushroom Lignosus rhinocerotis, were cloned and heterologously expressed in a yeast system. Results: Metabolite profile analysis of the yeast culture extracts by GC-MS showed the production of several sesquiterpene alcohols (C 15 H 26 O), including cadinols and germacrene D-4-ol as major products. Other detected sesquiterpenes include selina-6-en-4-ol, ß-elemene, ß-cubebene, and cedrene. Two purified major compounds namely (+)-torreyol and a-cadinol synthesised by GME3638 and GME3634 respectively, are stereoisomers and their chemical structures were confirmed by 1 H and 13 C NMR. Phylogenetic analysis revealed that GME3638 and GME3634 are a pair of orthologues, and are grouped together with terpene synthases that synthesise cadinenes and related sesquiterpenes. (+)-Torreyol and a-cadinol were tested against a panel of human cancer cell lines and the latter was found to exhibit selective potent cytotoxicity in breast adenocarcinoma cells (MCF7) with IC 50 value of 3.5 ± 0.58 µg/ml while a-cadinol is less active (IC 50 = 18.0 ± 3.27 µg/ml). Conclusions: This demonstrates that yeast-based genome mining, guided by transcriptomics, is a promising approach for uncovering bioactive compounds from medicinal mushrooms

SUBSHELL SELECTIVE ELECTRON CAPTURE IN COLLISION OF O4+ WITH H2 AT 40 keV

La collision d'échange de charge entre des ions O4+ de 40 kev et de l'hydrogène moléculaire a bté observée par spectroscopie optique dans l'u.v.. En plus des transitions entre états doublets avec coeur 1s22s2, les transitions entre états doublets et quadruplets avec coeur 1s22s2p ont été observées. Les niveaux n=3 de OIV sont préférentlellement peuplés. Les sections efficaces absolues ont été mesurées.u.v. photon spectroscopy of charge exchange collision between O4+ (40 kev) ions and H2 has been observed. In addition to the transitions between doublet states with 1s22s2 core, transitions between doublet and quartet states with 1s22s2p core have been observed n=3 levels of OIV are selecttvely populated. Absolute cross sections have been measured

5-Hydroxytryptamine-Derived Alkaloids from Two Marine Sponges of the Genus Hyrtios

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

LOW ENERGY CHARGE EXCHANGE BETWEEN Nq+, Neq+ AND Arq+ WITH Cs

Les ions multichargés Nq+ (q=5), Neq+ (q=5,8) et Arq+ (q=8,9) ont été étudiés par spectroscopie optique lors de la collision d'échange de charge avec une vapeur de Caesium. Les états de Rydberg sont peuplés par capture électronique. Les transitions entre états de Rydberg doublement excités 1s2 2s2 2p5 3s nl 4LJ - 1s2 2s2 2p5 3s n'l' 4L'J' with n=7,..., 12 et l=6,..., 11 ont été observées par double collision avec Ar9+.Optical spectroscopy studies have been performed with Nq+ (q=5), Neq+ (q=5,8) and Arq+ (q= 8,9) multicharged ions. Rydberg states were populated by electron capture from Caesium. Doubly excited 1s2 2s2 2p5 3s nl 4LJ - 1s2 2s2 2p5 3s n'l' 4L'J' with n=7,..., 12 and l=6,..., 11 Rydberg transitions of Ar VIII have been observed by double collision with Ar9+

High electron stabilization rate in slow collisions of bare Ne

We report cross-section measurements of collisions between bare Ne10+ ions and C60 at two different collision velocities (v=0.3 and 0.64 a.u.). We focus our attention on small impact parameter collisions ($b<{\rm C}_{60}$ radius), in which C60 can be considered as a nanometric solid target. The final charge state distribution corresponding to these small impact parameter events is modeled using a multi-cascade charge equilibration model. We show that for bare Ne10+ ions, the initial emptiness of the n=1 shell leads to higher rates for the stabilization on the projectile of the first two electrons

(2R,3R,7Z)-2-Aminotetradec-7-ene-1,3-diol, A new amino alcohol from the caribbean sponge Haliclona vansoesti

SCOPUS: ar.jinfo:eu-repo/semantics/publishe