Biosynthesis of Leaf Alcohol Formation of 3Z-Hexenal from Linolenic Acid in Chloroplasts of Thea sinensis Leaves

The synthetic activity for 3Z-hexenal, an important precursor of 3Z-hexenol (leaf alcohol), was localized in chloroplasts of Thea sinensis leaves. 3Z-Hexenal, which is easily isomerized to 2E-hexenal (leaf aldehyde), was formed from linolenic acid in the presence of oxygen. 13-l-Hydroperoxy-linolenic acid also served as a precursor, but the triglyceride and methyl ester of linolenic acid did not. This enzyme system appeared to be tightly bound to the lamellae membranes of chloroplasts.     

The Role of L-DOPA on Melanization and Mycelial Production in Malassezia Furfur

Melanins are synthesized by organisms of all biological kingdoms and comprise a heterogeneous class of natural pigments. Certain of these polymers have been implicated in the pathogenesis of several important human fungal pathogens. This study investigated whether the fungal skin pathogen Malassezia furfur produces melanin or melanin-like compounds. A melanin-binding monoclonal antibody (MAb) labelled in vitro cultivated yeast cells of M. furfur. In addition, melanization of Malassezia yeasts and hyphae was detected by anti-melanin MAb in scrapings from patients with pityriasis versicolor. Treatment of Malassezia yeasts with proteolytic enzymes, denaturant and concentrated hot acid yielded dark particles and electron spin resonance spectroscopy revealed that these particles contained a stable free radical compound, consistent with their identification as melanins. Malassezia yeasts required phenolic compounds, such as L-DOPA, in order to synthesize melanin. L-DOPA also triggered hyphal formation in vitro when combined with kojic acid, a tyrosinase inhibitor, in a dose-dependent manner. In this respect, L-DOPA is thought to be an essential substance that is linked to both melanization and yeast-mycelial transformation in M. furfur. In summary, M. furfur can produce melanin or melanin-like compounds in vitro and in vivo, and the DOPA melanin pathway is involved in cell wall melanization.     

Fate of Legionella pneumophila in macrophages of C57BL/6 chronic granulomatous disease mice

We compared the intracellular survival and growth of Legionella pneumophila Philadelphia-1 in peritoneal macrophages obtained from A/J, C57BL/6, and X-linked chronic granulomatous disease (CGD) mice produced from C57BL/6 strain. The initial killing was observed in A/J and C57BL/6 macrophages at 2, 4 and 6 hr after in vitro phagocytosis, but not in the CGD macrophages. Thereafter, there was a 10-fold increase of CFU in A/J macrophages. The bacteria, however, did not proliferate in C57BL/6 and CGD macrophages at 24 or 48 hr after in vitro phagocytosis. These results suggest that effector molecules for the initial killing are a superoxide anion and its metabolites, and Lgn1 gene product inhibits the intracellular growth of L. pneumophila independently of NADPH oxidase.     

Neodictyoprolenol and dictyoprolenol, the possible biosynthetic intermediates of dictyopterenes, in the Japanese brown algae Dictyopteris

Neodictyoprolenol [(-)-(3S)-(1,5Z,8Z)-undecatrien-3-ol] and dictyoprolenol [(-)-(3S)-(1,5Z,8Z)-undecadien-3-ol]), which had been proposed as possible biosynthetic intermediates of the sex pheromones of marine brown algae such as dictyopterene B [(-)-trans-1-((1'E,3'Z)-hexadienyl)-2-vinylcyclopropane], D' [(+)-6-((1'Z)-butenyl)-1,4-cycloheptadiene] and C' [(+)-6-butyl-1,4-cycloheptadiene], were again identified in the essential oils from Dictyopteris prolifera, D. latiscula, and in D. undulata, together with the C11-related volatile compounds such as neodictyoprolene, dictyoprolene and dictyopterenes. Incubation of D. prolifela preparation with racemic neodictyoprolenol and dictyoprolenol as substrates showed (S)-enantioselective decreases of the added substrates and increases in dictyopterenes. From these results, a possible pathway to form dictyopterenes is discussed.     

Linoleic acid 10-hydroperoxide as an intermediate during formation of 1-octen-3-ol from linoleic acid in Lentinus decadetes

In order to confirm the biosynthetic pathway to 1-octen-3-ol from linoleic acid, a crude enzyme solution was prepared from the edible mushroom, Lentinus decadetes. When the reaction was performed in the presence of glutathione peroxidase, which can reduce organic hydroperoxide to the corresponding hydroxide, the amount of 1-octen-3-ol formed from linoleic acid was decreased. At the same time, an accumulation of linoleic acid 10-hydroxide could be detected. The 10-hydroperoxide therefore seems to be an intermediate on the biosynthetic pathway.     

Global stability of pathogen-immune dynamics with absorption

In this paper, we consider the global stability of the models which incorporate humoural immunity or cell-mediated immunity. We consider the effect of loss of a pathogen, which is called the absorption effect when it infects an uninfected cells. We construct Lyapunov functions for these models under some conditions of parameters, and prove the global stability of the interior equilibria. It is impossible to remove the condition of parameters for the model incorporating humoural immunity.     

Synthesis and pharmacological profile of serofendic acids A and B

We present efficient syntheses of serofendic acids A and B (SA-A and SA-B), novel neuroprotective substances isolated from fetal calf serum. Biological and pharmacological evaluation showed that SA-A and SA-B have potent protective action against glutamate-induced neurotoxicity, but do not interact directly with glutamate receptors. A pharmacokinetic study showed that they have good oral bioavailability in rats. The results indicate that SA-A and SA-B are potential lead compounds for candidate drugs to treat various neurological disorders.