Takehara Munenori, Nishimura Masatoshi, Kuwa Takahiro, Inoue Yoshinori, Kitamura Chitoshi, Kumagai Tsutomu, Honda Masaki
Department of Materials Science, The University of Shiga Prefecture , Hassaka, Hikone 522-8533, Japan.
J Agric Food Chem. 2014 Jan 8;62(1):264-9. doi: 10.1021/jf404497k. Epub 2013 Dec 27.
A large amount of (all-E)-lycopene was successfully purified from tomato paste using an improved method that included a procedure to wash crystalline powder with acetone. The total yield of the pure (all-E) form was at least 30%. The melting point of (all-E)-lycopene was determined to be 176.35 °C by differential scanning calorimetry (DSC) measurements. Bathochromic shifts were observed in the absorption maxima of all solvents tested (at most a 36 nm shift for λ2 in carbon disulfide, as was observed in hexane) and were accompanied by absorbance decreases, namely, a hypochromic effect, showing a higher correlation between the position and the intensity of the main absorption bands. This bathochromic shift was dependent upon the polarizability of the solvent rather than its polarity. The structure of (all-E)-lycopene in CDCl3 and C6D6 was identified on the basis of one- and two-dimensional nuclear magnetic resonance (NMR) spectra, including (1)H and (13)C NMR, homonuclear correlation spectroscopy ((1)H-(1)H COSY), heteronuclear multiple-quantum coherence (HMQC), and heteronuclear multiple-bond connectivity (HMBC). The rate constants of the decrease in (all-E)-lycopene with hexane and benzene were calculated to be 3.19 × 10(-5) and 3.55 × 10(-5) s(-1), respectively. The equilibrium constants between (all-E) and (13Z) isomers were estimated to be 0.29 in hexane and 0.31 in benzene, respectively, from the point at which the amount of (13Z)-lycopene reached its maximum.
采用一种改进方法从番茄酱中成功纯化出大量的（全 - E）- 番茄红素，该方法包括用丙酮洗涤结晶粉末的步骤。纯（全 - E）形式的总产率至少为30%。通过差示扫描量热法（DSC）测量，（全 - E）- 番茄红素的熔点测定为176.35℃。在所测试的所有溶剂的吸收最大值处均观察到红移（在二硫化碳中λ2处最大红移为36nm，如在己烷中观察到的那样），并且伴随着吸光度降低，即减色效应，这表明主吸收带的位置和强度之间存在更高的相关性。这种红移取决于溶剂的极化率而非其极性。基于一维和二维核磁共振（NMR）光谱，包括（1）H和（13）C NMR、同核相关光谱（（1）H - （1）H COSY）、异核多量子相干（HMQC）和异核多键连接（HMBC），确定了（全 - E）- 番茄红素在CDCl3和C6D6中的结构。计算得出（全 - E）- 番茄红素在己烷和苯中减少的速率常数分别为3.19×10^(-5)和3.55×10^(-5) s^(-1)。从（13Z）- 番茄红素的量达到最大值的点估计，（全 - E）和（13Z）异构体之间在己烷中的平衡常数为0.29，在苯中为0.31。
