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Tea polyphenols are strong antioxidants, which can be rapidly O-methylated by catechol-O-methyltransferase (COMT). Thus, it is possible that the genetic polymorphism of COMT can modulate the association of green tea consumption and lung cancer. Here, we designed a case-control study to evaluate the combined effect of green tea consumption and COMT genotypes on the risk of lung cancer. A total of 237 lung cancer patients and 474 healthy controls were recruited. Questionnaires were administered to obtain demographic data, smoking status, green tea consumption, fruits and vegetables intake, exposure to cooking fumes, and family history of lung cancer. Genotypes for COMT were identified by PCR. Smoking, green tea consumption, exposure to cooking fumes, and family history of lung cancer were associated with the development of lung cancer. When green tea drinkers carrying COMT HL/LL genotypes were selected as the reference group, drinkers carrying the COMT HH genotype had a higher risk for the development of lung cancer (odds ratio: 1.97, 95% confidence interval: 0.99-3.91). Among the current and ever smokers, the elevated risk for lung cancer was more apparent in green tea drinkers carrying the COMT HH genotype compared with green tea drinkers carrying COMT HL/LL genotypes (odds ratio: 5.84, 95% confidence interval: 1.75-19.45). Green tea drinkers with greater activity of the COMT genotype, whereby polyphenols are effectively excluded, will gain fewer protective benefits against lung cancer development.

FR901464, an antitumor natural product, represents a new class of potent anticancer small molecules targeting spliceosome and inhibiting both splicing and nuclear retention of pre-mRNA. Herein we describe the biosynthetic gene cluster of FR901464, identified by degenerate primer PCR amplification of a gene encoding the 3-hydroxy-3-methylglutaryl-CoA synthase (HCS) postulated to be involved in the biosynthesis of a β-branched polyketide from Pseudomonas sp. No. 2663. This cluster consists of twenty open reading frames (ORFs) and was localized to 93-kb DNA segment, and its involvement in FR901464 biosynthesis was confirmed by gene inactivation and complementation. FR901464 is biosynthesized by a hybrid polyketide synthase (PKS)/nonribosomal peptide synthetase (NRPS), HCS, and acyltransferases (AT)-less system. The PKS/NRPS modules feature unusual domain organization including multiple domain redundancy, inactivation, and tandem. Biochemical characterization of a glyceryl transferase and an acyl carrier protein (ACP) in the start module revealed that it incorporates D-1,3-bisphosphoglycerate, which is dephosphorylated and transferred to ACP as the starter unit. Furthermore, an oxidative Baeyer-Villiger reaction followed by chain release was postulated to form a pyran moiety. On the basis of in silico analysis and genetic and biochemical evidances, a biosynthetic pathway for FR901464 was proposed, which sets the stage to further investigate the complex PKS biochemically and engineer the biosynthetic machinery for the production of novel analogues.

This paper has employed the nonparametric minimum convex input requirement set (MCIRS) approach to measure the premarket underpricing and aftermarket inefficiency in Taiwan's initial public offerings (IPOs). The empirical results show that first, the average level of underpricing in Taiwan's IPO premarket is 15.66%, and underpricings in the hot- and nonhot-market periods are not different. Second, underpricing in the electronic IPOs (purchased by both (informed) institutional investors and (uninformed) individual investors) is not different from that in the non-electronic IPOs (purchased by (uninformed) individual investors). This result rejects Rock's (1986) winner's curse explanation for IPO underpricing. Third, in the nonhot-market period, premarket underpricing disappears on one week after trading (i.e., there is no aftermarket inefficiency), and in the hot-market period, new issues are overpriced on one week after trading (i.e., there is an aftermarket inefficiency). The paper also finds that the commonly used method of valuing IPOs with price-earnings (P/E), market-to-book and price-to-sales multiples of comparable firms performs poorly in Taiwan's IPOs. The predictability of the comparable firms method improves when the market values-to-sales and enterprise value-to-sales multiples are used.

0009-3130/11/4704-0658 2011 Springer Science+Business Media, Inc. College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, P. R. China, fax: 86 21 67792608, e-mail: zyshao@dhu.edu.cn. Published in Khimiya Prirodnykh Soedinenii, No. 4, p. 577, July–August, 2011. Original article submitted March 26, 2010. Chemistry of Natural Compounds, Vol. 47, No. 4, September, 2011 [Russian original No. 4, July–August, 2011]