1.Isolation of 9-hydroxy-delta-tetradecalactone from lipid A of Pseudomonas diminuta and Pseudomonas vesicularis.
Arata S1, Hirayama T, Kasai N, Itoh T, Ohsawa A. FEMS Microbiol Lett. 1989 Jul 15;51(1):219-22.
A lipid component was isolated from the fatty acid fraction of acid hydrolysates of lipid A derived from Pseudomonas diminuta JCM 2788 and Pseudomonas vesicularis JCM 1477 lipopolysaccharides. By structural analysis of the lipid and its trimethylsilyl and acetyl derivatives by thin-layer chromatography, gas chromatography-mass spectrometry, mass spectrometry, infrared spectrometry and 13C-NMR, it was identified as 9-hydroxy-delta-tetradecalactone.
2.Promotive effects of hyperthermia on the cytostatic activity to Ehrlich ascites tumor cells by diverse delta-alkyllactones.
Tanaka H1, Kageyama K, Asada R, Yoshimura N, Miwa N. Exp Oncol. 2008 Jun;30(2):143-7.
AIM: To evaluate promotive effects of hyperthermia on antitumor activity of new delta-alkyllactones (DALs) of low molecular weight (184-254 Da), chemically synthesized, which are different from natural macrocyclic lactones of high molecular weight (348-439 Da), such as camptothecin and sultriecin.
3.Sensory-directed identification of creaminess-enhancing volatiles and semivolatiles in full-fat cream.
Schlutt B1, Moran N, Schieberle P, Hofmann T. J Agric Food Chem. 2007 Nov 14;55(23):9634-45. Epub 2007 Oct 13.
Aimed at defining the chemical nature of creaminess-related flavor compounds in dairy products on a molecular level, a full-fat cream was analyzed for sensorially active volatiles and semivolatiles by means of activity-guided screening techniques. Application of the aroma extract dilution analysis on an aroma distillate prepared from pasteurized cream (30% fat) revealed delta-decalactone, (Z)-6-dodeceno-gamma-lactone, gamma-dodecalactone, delta-dodecalactone, and 3-methylindole with by far the highest flavor dilution (FD) factors among the 34 odor-active volatiles identified. Using a complementary approach involving silica column chromatography and fractionated high-vacuum distillation combined with sensory experiments enabled the additional identification of delta-tetradecalactone, delta-hexadecalactone, gamma-tetradecalactone, gamma-hexadecalactone, and delta-octadecalactone as semivolatile flavor components in the cream fat. Although a series of lactones is present in dairy cream, spiking of cream samples with individual lactones revealed that only the delta-tetradecalactone is able to enhance the typical retronasal creamy flavor of the product when added in amounts above its threshold level of 66 micromol/kg.
4.Effect of α-tocopherol on lactone formation in marbled beef and changes in lactone volatility during storage.
Watanabe A1, Imanari M, Yonai M, Shiba N. J Food Sci. 2012 Jun;77(6):C627-31. doi: 10.1111/j.1750-3841.2012.02694.x. Epub 2012 May 14.
Dynamic-headspace sampling with a standard-addition method was employed to quantitatively analyze aliphatic lactones in rendered fat from marbled beef and to evaluate the effect of the matrix on volatility. Further, the effects of different levels of the antioxidant α-tocopherol on lactone formation were examined. The slopes of the linear regression curves from the standard-addition method were significantly changed (P < 0.05 or 0.01) for all lactones after storage, with the exception of γ-octalactone, indicating the volatility of the longer-chain lactones were increased after storage. The concentrations of γ-lactones were increased after 7 d of storage at 2 °C (P < 0.01), and the α-tocopherol content in the meat affected the formation of γ-octalactone (P < 0.05) and γ-nonalactone (P < 0.01). The greatest increase was observed for γ-nonalactone in the lowest α-tocopherol (2.9 ppm) group: the concentration of 51.4 ppb was 11.7-fold higher than that before storage.