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Yarrowia lipolytica is an oleaginous yeast that is recognized for its ability to accumulate high levels of lipids, which can serve as precursors to biobased fuels and chemicals. Polyketides, such as triacetic acid lactone (TAL), can also serve as a precursor for diverse commodity chemicals. This study used Y. lipolytica as a host organism for the production of TAL via expression of the 2-pyrone synthase gene from Gerbera hybrida. Induction of lipid biosynthesis by nitrogen-limited growth conditions increased TAL titers. We also manipulated basal levels of TAL production using a DNA cut-and-paste transposon to mobilize and integrate multiple copies of the 2-pyrone synthase gene. Strain modifications and batch fermentation in nitrogen-limited medium yielded TAL titers of 2.6 g/L. Furthermore, we show that minimal medium allows TAL to be readily concentrated at >94% purity and converted at 96% yield to pogostone, a valuable antibiotic. Modifications of this reaction scheme yielded diverse related compounds. Thus, oleaginous organisms have the potential to be flexible microbial biofactories capable of economical synthesis of platform chemicals and the generation of industrially relevant molecules.

Nigerapyrone A, aloenin aglycone, 4′-methyl klavuzon, and allantopyrone C were synthesized from commercially available aldehydes. [ABSTRACT FROM AUTHOR]

Our objective in this study was to determine whether a mitochondda-targeted vitamin E derivative (MitoVit E) would decrease oxidative stress and associated obesity by preventing a previously proposed aconitase inhibition cascade. Sixty-four mice were fed a high-fat (HF) diet for 5 wk. They were then switched to either a low-fat (LF) or a medium-fat (MF) diet and gavaged with MitoVit E (40 mg MitoVit E kg body [weight.sup.-1]) or drug vehicle (10% ethanol in 0.9% NaCl solution) every other day for 5 wk. Epididymal fat weight, as well as liver lipid and remaining carcass lipid, were significantly lower in the MF group receiving MitoVit E (MF-E) than in the MF group receiving vehicle only (MF-C). Liver mitochondrial [H.sub.2][O.sub.2] production and the protein carbonyl level were also significantly lower in MF-E than in MF-C mice. In contrast, none of the biochemical variables (aconitase activity, ATP and [H.sub.2][O.sub.2] production, and protein carbonyl level) in the muscle mitochondria were modified by MitoVit E in either MF or LF groups. Expression of acetyl-CoA carboxylase and fatty acid synthase in both liver and adipose tissue of MF groups was not affected by MitoVit E. However, expression of carnitine palmitoyltransferase 1 a in the liver and uncoupling protein 2 in adipose tissue were significantly enhanced by MitoVit E in both LF and MF groups. In conclusion, MitoVit E attenuates hepatic oxidative stress and inhibits fat deposition in mice but not through alleviation of the aconitase inhibition cascade. doi: 10.3945/jn.110.121715.

Makaluvamine C is a pyrroloiminoquinone which was extracted from marin sponges. The said alkaloid was synthesized in 13 steps from p-anisidine, The major steps in this synthesis include an intramolecular nucleophilic aromatic substitution mediated by potassium tert-butoxide, the selective reduction of a dinitro ester utilizing catalytic hydrogenation, and the unique application of Fremy's salt to synthesize an iminoquinone from an amino phenol. Synthesis of the alkaloid from p-anisidine provided a 13.1% overall yield.

Anthraquinone products such as daunomycin and aclacinomycin have been the subject of much research since the 1970s, mainly in the area of toxicology. In the 1990s, the focus of this type of research has shifted to biologically active quinones, particularly those that are angularly fused since this class of quinones exhibit strong inhibitory activity and high antiretroviral potency. A method for directly synthesizing G-2N, which is one of the more interesting members of this quinone class, is presented.

The dramatic rise in HIV-infected persons has significantly contributed to the explosion of interest in the approaches to antiviral therapies. This review focuses on elucidating the antiviral activity of naturally occurring polycyclic quinone hypericin. The discussion includes the dependence on light of this antiviral drug for virucidal activity through targeted light delivery, also referred to as the 'molecular flashlight.' The synthesis of the components of molecular flashlight and the mechanism involved in its intermolecular proton transfer is also presented.

A six-step synthetic sequence helps convert a ketone into frenolicin B, an anticoccidial agent. An antifungal agent, kalafungin, is prepared by a five-step synthetic sequence. A regioselective Diels-Alder reaction is the vital step in both the sequences. Both electrostatic repulsion and induction of ring-puckering in the quinone subunit by the lactone ring are responsible for the regioselectivity in these syntheses.

Hongconin synthesis involved a six-membered ring formation through mercury-mediated cyclization, benzylic alcohol metalation and regioselective installation of the naphthalene ring through a Diels-Alder reaction. Hongconin, a new naphthohydroquinone, revealed cardioprotective activity against angina pectoris.