THE DETERMINATION OF HYDROXYLATED NATURAL PRODUCTS

7-[(氯羰基)甲氧基]-4-甲基香豆素1正在开发中 用于伯仲羟基荧光标记的LPC 组。我们已经开发出了允许克级的合成程序 生产高纯度的1，我们已经发现这种试剂可以反应 顺畅地与各种伯次羟基化合物 给出相应的酯类。这些酯很容易从反转的- 相液相色谱柱，从而允许通过标准方法进行检测，例如 紫外光、荧光或质谱仪。然而，一个小的，但高度的 荧光杂质被发现，分离，并随后 已确认身份。这种杂质的来源被追溯到一种副反应 7-(羧甲氧基)-4-甲基香豆素与亚硫酰氯反应 一种新的基于香豆素的酰化试剂3-氯-7- [(氯羰基)甲氧基]-4-甲基-香豆素。我们已经开发出合成的 现在允许这种新试剂的克级生产的程序。 这种新试剂提供的荧光团要多出许多倍 荧光比相应的非氯化类似物低，从而降低 潜在应用中的检测极限。在派生时 具有羟基部分的化合物，我们发现其反应性和 这种新试剂的选择性与7-甲氧基苯乙酸乙酯的选择性相似。 [(氯羰基)甲氧基]-4-甲基香豆素； 很容易从反相高效液相色谱柱上洗脱，从而允许 简捷的分析。

7-[(Chlorocarbonyl)methoxy]-4-methylcoumarin 1 has been under development in LPC for the fluorescent labeling of primary and secondary hydroxyl groups. We have developed synthetic procedures which allow the gram-scale production of 1 in high purity, and we have found this reagent to react smoothly with a variety of primary and secondary hydroxyl compounds to give the corresponding esters. These esters readily elute from reversed- phase HPLC columns, thereby allowing detection by standard methods such as UV, fluorescence, or mass spectrometry. However, a small, but highly fluorescent impurity was discovered, isolated, and subsequently identified. The origin of this impurity was traced to a side-reaction of 7-(carboxymethoxy)-4-methylcoumarin with thionyl chloride, leading us to a new, coumarin-based, acylation reagent, 3-chloro-7- [(chlorocarbonyl)methoxy]-4-methyl-coumarin. We have developed synthetic procedures which now allow the gram-scale production of this new reagent. This new reagent provides a fluorophore which is many times more fluorescent than the corresponding non-chlorinated analog, thus lowering the limit of detection in potential applications. Upon derivatizing compounds which possess a hydroxyl moiety, we find the reactivity and selectivity of this new reagent similar to that of 7- [(chlorocarbonyl)methoxy]-4-methylcoumarin; the resulting derivatives also readily elute from reversed-phase HPLC columns, thereby allowing for facile analysis.