Lee-Fong Yau

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The rat is an important alternative for studying human pathology owing to certain similarities to humans. Glycomic studies on rat serum have revealed that variations in the N-glycans of glycoproteins correlated with disease progression, which is consistent with the findings in human serum. Therefore, we comprehensively characterized the rat serum N-glycome(More)
Quantitative comparison of seven ginsenosides in wild and cultivated American ginseng revealed that the Rg(1)/Rd ratio presented a significantly large difference between cultivated and type-I (one of the defined chemotypes) wild American ginseng, facilitating this ratio as a characteristic marker for differentiating these two groups. Similarly, the ratio(More)
Although both rhizome and root of Panax notoginseng are officially utilized as notoginseng in "Chinese Pharmacopoeia", individual parts of the root were differently used in practice. To provide chemical evidence for the differentiated usage, quantitative comparison and metabolite profiling of different portions derived from the whole root, as well as(More)
Catechins and procyanidins, together with flavonoid glycosides and terpene trilactones, are three important categories of components in the standard extract of Ginkgo biloba leaves (EGb761). In this research, catechins and proanthocyanidins were found to exist in both the extract of Ginkgo leaves and Ginkgo products. By comparing with reference compounds,(More)
Oxygenated metabolites have been suggested as the major circulating metabolites of ginsenosides. In the current study, 10 oxygenated metabolites of ginsenoside Rb1 in plasma and urine of rat following iv dose were characterized by comparison with chemically synthesized authentic compounds as quinquenoside L16 (M1 and M2), notoginsenoside A (M3), ginsenoside(More)
The standard extract of Ginkgo biloba leaves (EGb761) is used clinically in Europe for the symptomatic treatment of impaired cerebral function in primary degenerative dementia syndromes, and the results of numerous in vivo and in vitro studies have supported such clinical use. The abnormal production and aggregation of amyloid β peptide (Aβ) and the(More)
Two new dehydromonacolins (1 and 3), together with nine known monacolins (4-12), were isolated from red yeast rice. Compounds 4-6 were isolated from a natural resource for the first time. Their structures were elucidated by means of NMR and mass spectroscopic analyses. The structure of dehydromonacolin N (1) was further confirmed by its semisynthesis from(More)
Millions of individuals are vaccinated worldwide each year to stimulate their adaptive immune systems to produce protective antibodies and T-cell response against pathogens. Since glycosylation of the Fc region of immunoglobulin G (IgG) can be influenced by the host's immune status, it was inferred that glycosylation profile of IgG might be altered as a(More)
Drug resistance elicited by cancer cells continue to cause huge problems world-wide, for example, tens of thousands of patients are suffering from taxol-resistant human ovarian cancer. However, its biochemical mechanisms remain unclear. Sphingolipid metabolic dysregulation has been increasingly regarded as one of the drug-resistant mechanisms for various(More)
This study describes the characterization of oxygenated metabolites of ginsenoside Rg1 in rat urine and plasma. These in vivo metabolites were profiled by using UHPLC-QTOF MS-based method. On the basis of high-resolution MS/MS data, and comparison with chemically synthesized authentic compounds, nine oxygenated metabolites of Rg1 were characterized as(More)