Recently, several studies have indicated that an adequate intake of menaquinone-7 (MK-7) offers numerous health benefits. However, the low availability of MK-7 in the diet necessitates the development of dietary supplements or functional food products to complement natural food sources and meet the daily intake requirements. Like most biological molecules, MK-7 can exist as geometric isomers that can occur in the cis, trans, and cis/trans forms; however, only the all-trans form is biologically significant. MK-7 is traditionally produced through bacterial fermentation, but various synthetic preparations have lately become available. The isomer composition in the final product is influenced by numerous factors, including the methods of production and purification, as well as particular environmental and storage conditions. The MK-7 profile obtained from the various production methods has not yet been elucidated, and the ideal method for the synthesis of the all-trans form of the vitamin is also debatable. Consequently, the quantification of the MK-7 profile of various products is necessary to develop an understanding of the factors that influence the proportion of isomers that are obtained in different preparations. Several possible methods exist for the quantification of MK-7 isomers, and of these, liquid chromatography in conjunction with mass spectrometry techniques appears to be the most promising. Evaluation of the isomer composition is an important consideration, as only the all-trans form sustains biological activity. Furthermore, knowledge of the prominent factors that influence the MK-7 composition may also enable their manipulation to obtain a more favorable MK-7 profile in the final product.

中文翻译：

---

维生素menaquinone-7的顺式和反式异构体：哪一种具有生物学意义？

最近，几项研究表明，摄入足够的甲萘醌 7 (MK-7) 可带来许多健康益处。然而，饮食中 MK-7 的低可用性需要开发膳食补充剂或功能性食品，以补充天然食物来源并满足日常摄入需求。与大多数生物分子一样，MK-7 可以以顺式、反式和顺/反式的几何异构体形式存在；然而，只有全反式具有生物学意义。MK-7 传统上是通过细菌发酵生产的，但最近出现了各种合成制剂。最终产品中的异构体组成受多种因素影响，包括生产和纯化方法，以及特定的环境和储存条件。从各种生产方法中获得的 MK-7 谱尚未阐明，合成维生素全反式的理想方法也存在争议。因此，有必要对各种产品的 MK-7 谱进行量化，以了解影响在不同制剂中获得的异构体比例的因素。有几种可能的方法可用于定量 MK-7 异构体，其中液相色谱与质谱技术相结合似乎是最有希望的。异构体组成的评估是一个重要的考虑因素，因为只有全反式才能维持生物活性。此外，