The results are reported of mass-spectrometric studies of the nucleobases adenine 1h (1, R = H), guanine 2h, and cytosine 3h. The protonated nucleobases are generated by electrospray ionization of adenosine 1r (1, R = ribose), guanosine 2r, and deoxycytidine 3d (3, R = deoxyribose) and their fragmentations were studied with tandem mass spectrometry. In contrast to previous EI-MS studies of the ...

Several factors can affect lamb body weight (BW) and immune status during the first days of life, including colostrum source and timing of the first colostrum feeding. The aim of this study was to evaluate the effects of colostrum source (goat or sheep) and timing of the first colostrum feeding (2 or 14h after birth) on lamb BW and immune status. In this study, 40 lambs were removed from their ...

The aims of this study were to analyze dynamic stem elongation standard cut-chrysanthemum (Dendranthema grandiflorum) with different photoperiod levels. Standard cv. Baekma was grown at a 16 hr until 23 days after planting, that photoperiods 8, 10, 12, 14, and (8H, 10H, 12H, 14H, 16H) applied using fluorescent lights in plant factory. long-day treatments 14H 16H produced no flower buds the 8H t...

THE TITLE COMPOUND [SYSTEMATIC NAME: 17-(5,6-di-methyl-hept-6-en-2-yl)-4,4,10,13,14-penta-methyl-1,5,6,10,11,12,13,15,16,17-deca-hydro-2H-cyclo-penta-[α]phenanthren-3(4H,9H,14H)-one], C(31)H(50)O, is a triterpenoid which was isolated from Skimmia laureola. The three six-membered rings adopt chair, slightly distorted half-chair and distorted boat conformations, and the five-membered ring is in a...

A convenient and efficient procedure for the synthesis of 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes by condensation of 2-naphthol and aldehydes in the presence of Methylimidazolium hydrogensulfate, as a Brönsted acidic ionic liquid ([Hmim]HSO4), is described. Both aromatic and aliphatic aldehydes reacted easily to afford the corresponding 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes in good yiel...

Ceramides containing either sphingosine or sphinganine and one of the 2-hydroxy acids, 14h:0, 16h:0, 18h:0, 20h:0, 22h:0, 24h:0, and 26h:0 were prepared and separated by gas chromatography as the 1,3,2'-tri-O-tri-methylsilyl derivatives. Mass spectrometric analyses of these derivatives showed that the ions formed on electron impact can be used to determine unequivocally the structures of the lo...

A simple synthetic route affording 27%-85% yields of benzo[6,7][1,5]diazocino[2,1-a]isoindol-12(14H)-one ring systems from readily available 3-(2-oxo-2-phenylethyl) isobenzofuran-1(3H)-ones and 2-(aminomethyl)aniline starting materials in toluene and catalysed by p-toluene-sulfonic acid is developed. The ¹H- and (13)C-NMR spectra of the final products were assigned using a variety of one and tw...