ABSTRACT
We report the generation of picosecond pulsed light at a 266â nm wavelength with an average power of 53 W. We developed a picosecond pulsed 1064â nm laser source with an average power of 261 W, a repetition rate of 1â MHz, and a pulse duration of 14 ps, using a gain-switched DFB laser diode as a seed laser and a 914â nm laser-diode-pumped Nd-doped YVO4 power amplifier. We achieved stable generation of 266â nm light with an average power of 53 W from frequency quadrupling using an LBO and a CLBO crystals. The amplified power of 261 W and the 266â nm average power of 53 W from the 914â nm pumped Nd:YVO4 amplifier are the highest ever reported, to the best of our knowledge.
ABSTRACT
A new compound, 3-O-(4-O-methyl-ß-D-glucopyranosyl) xanthone (1) was isolated from the culture of Conoideocrella luteorostrata NBRC106950. The structure of 1 was mainly determined by 1H, 13C, 2D-NMR and HREIMS spectral analyses. The absolute configuration of 4-O-methylglucopyranosyl moiety was determined by the optical rotation of aqueous layer of hydrolyzed 1 as D-configuration.
Subject(s)
Hypocreales , Xanthones , Animals , Glucosides , Hypocreales/chemistry , Insecta , Molecular Structure , Xanthones/chemistryABSTRACT
A simple and compact spectral-broadening system is presented that is based on a single-stage statically pressurized Ar filled hollow core fiber. By optimizing the inner diameter of the hollow core fiber, a bandwidth of 300 nm is obtained. This is the broadest bandwidth known to date with millijoule level energy near the 1-µm wavelength by a single stage gas filled hollow core fiber.
ABSTRACT
During the search for new antitrypanosomal drug leads, four antitrypanosomal compounds, of three depsipeptides and one nortriterpenoid, were isolated from cultures of the mutant strain IU-3 of the insect pathogenic fungus Ophiocordyceps coccidiicola NBRC 100683. Their structures were identified by the analysis of high resolution-electron ionization (HR-EI)-MS and HR-FAB-MS, and (1)H- and (13)C-NMR spectra, including extensive two dimensional (2D)-heteronuclear NMR experiments, and comparison with literature data for destruxin A (1), destruxin B (2), destruxin E chlorohydrin (3) and helvolic acid (4). Compounds 1-4 showed in vitro antitrypanosomal activity against Trypanosoma brucei brucei GUTat3.1 with IC50 values of 0.33, 0.16, 0.061 and 5.08 µg/mL, respectively.