The markers selected for this study ( Figure 1) are representative of two classes of phytoconstituents occurring in Ginkgo leaves: the species-specific terpene trilactones and the ubiquitous flavonoids. In this report, the complete 1H NMR assignments of ten standardization markers for the quality assessment of Ginkgo biloba preparations are presented. These beneficial effects make Ginkgo biloba one of the largest selling herbal products worldwide. During the last two decades, Ginkgo leaf preparations have been extensively studied for its antioxidant and neuroprotective properties. The dried Ginkgo leaves were typically used to treat asthma and circulatory diseases. In addition to its decorative use, Ginkgo preparations have been used for centuries as a component of traditional Chinese medicine. Originally found in China and Korea, Ginkgo has been widely planted as an ornamental tree in urban areas of North America, Europe and Japan due to its beauty, disease resistance, and longevity. The Ginkgo tree ( Ginkgo biloba L.) is the sole remaining species of the Ginkgoaceae family. Furthermore, precise 1H NMR assignments of the sugar moieties of isoquercetin and rutin are reported for the first time. As a result of this analysis, a revised set of 1H NMR parameters for all ten phytoconstituents was assembled. The capability of the HiFSA-generated 1H fingerprints to reproduce experimental 1H NMR spectra at different field strengths was also evaluated. The computational analysis of discrete spin systems allowed a detailed characterization of all the 1H NMR signals in terms of chemical shifts (δ H) and spin-spin coupling constants ( J HH), regardless of signal overlap and higher order coupling effects.
Inmr for pc full#
The comprehensive 1H NMR profiles (fingerprints) of ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, bilobalide, quercetin, kaempferol, isorhamnetin, isoquercetin, and rutin in DMSO- d 6 were obtained through the examination of 1D 1H NMR and 2D 1H, 1H-COSY data, in combination with 1H iterative Full Spin Analysis (HiFSA). The complete and unambiguous 1H NMR assignments of ten marker constituents of Ginkgo biloba are described.
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