Two new glycosides from Leonurus japonicus

Rapid classification and identification of chemical constituents in Leonurus japonicus Houtt based on UPLC-Q-Orbitrap-MS combined with data post-processing techniques

Leonurus japonicus Houtt (LJH) is a bulk medicinal material commonly used in clinical practice, but its complex constituents have not been completely understood, posing challenges to pharmacology, pharmacokinetic research, and scientific and rational drug use. As a result, it is critical to develop an efficient and accurate method for classifying and identifying the chemical composition of LJH. In this study, ultra-performance liquid chromatography-quadrupole electrostatic field-orbital trap high resolution mass spectrometry (UPLC-Q-Orbitrap-MS) was successfully established, along with two data post-processing techniques, characteristic fragmentations (CFs) and neutral losses (NLs), to quickly classify and identify the chemical constituents in LJH. As a result, 44 constituents of LJH were identified, including four alkaloids, 20 flavonoids, two phenylpropanoids, 17 organic acids, and one amino acid. The method in this paper enables classification and identification of chemical compositions rapidly, providing a scientific foundation for further research on the effective and toxic substances of LJH.

Correlation between quality and geographical origins of Leonuri Herba revealed by the qualitative fingerprint profiling and quantitative determination of chemical components

BACKGROUND

Leonuri Herba (Yimucao) is a very common Chinese herbs for treating menstrual and maternal diseases for thousands of years in China. However, the herb collected in different origins was easily found in the markets which induce the unstable quality for clinic use. In this study, a comprehensive strategy of using multiple chromatographic analysis and chemometric analysis was firstly investigated for chemical discrimination of Leonuri Herba from different geographical origins.

METHODS

UHPLC-QTOF-MS/MS was applied to identify the peaks of Leonuri Herba and chemical fingerprints were established in 30 batches from different geographical origins. Meanwhile, dissimilarities of chemical compositions among different origins were further investigated by principal component analysis and cluster analysis. And a quantitative UHPLC-QTOF-MS/MS approach were established to investigate the potential marker for quality control of Leonuri Herba.

RESULTS

A total of 49 chromatographic peaks of Leonuri Herba were identified by UHPLC-QTOF-MS/MS. Leonuri Herba were classified into four categories, and eight major compounds detected could be used as chemical markers for discrimination. Also, the eight components, including leonurine, 4',5-dihydroxy-7-methoxyflavone, rutin, hyperoside, apigenin, quercetin, kaempferol and salicylic acid, were simultaneously quantified using the extracting ion mode of UHPLC-QTOF-MS/MS.

CONCLUSION

The current strategy not only clearly expounded the correlation between quality and geographical origins of Leonuri Herba, but also provided a fast, accurate and comprehensive qualitative and quantitative method for assessing the quality of Leonuri Herba.

Cellular antioxidant activity and in vitro inhibition of α-glucosidase, α-amylase and pancreatic lipase of oregano polyphenols under simulated gastrointestinal digestion

Different oregano species have been traditionally used as infusions in folk medicine. Oregano medicinal properties, such as antioxidant and anti-inflammatory, have been partially attributed to its polyphenolic content. However, information regarding bioaccessibility of oregano polyphenols is limited. Cell-based antioxidant activity, and in vitro hypoglycemic, and hypolipidemic properties of polyphenolic extracts from three species of oregano species, namely, Hedeoma patens (HP), Lippia graveolens (LG) and Lippia palmeri (LP), subjected to simulated gastrointestinal digestion were evaluated. LC-TOF-MS analysis of HP, LG and LP allowed the identification of 9 flavonoids and 6 hydroxycinnamic acid derivatives with nutraceutical significance. Oregano polyphenolic extracts and digests from HP, LG, and LP exhibited cellular antioxidant capacity, hypoglycemic and hypolipidemic properties. Altogether, our results suggest that HP, LG and LP polyphenols exhibit potential for use as hypoglycemic, hypolipidemic, and antioxidant agents.

New diterpenoids isolated from Leonurus japonicus and their acetylcholinesterase inhibitory activity

Three new labdane diterpenoids, leojaponicone A (1), isoleojaponicone A (2) and methylisoleojaponicone A (3), were isolated from the herb of Leonurus japonicus. The chemical structures of these secondary metabolites were elucidated on the basis of 1D and 2D NMR, including HMQC, and HMBC spectroscopic techniques. All the new compounds were tested in vitro for their acetylcholinesterase and α-glucosidase inhibitory activity. Compounds 1-3 exhibited low inhibitory effects on α-glucosidase with respect to acarbose and exhibited high inhibitory effects on acetylcholinesterase with respect to huperzine A.

Leojaponic acids A and B, two new homologous terpenoids, isolated from Leonurus japonicus

The present study aimed at isolation and purification of the bioactive terpenoids from the herb of Leonurus japonicus by chromatographic separations such as silica gel, sephadex LH-20 and C18 reversed phase silica gel, as well as preparative HPLC. As a result, leojaponic acids A (1, C17H24O4) and B (2, C18H26O4), two homologous terpenoids, together with (-)-loliolide (3), 1-(3-ethylphenyl) ethane-1, 2-diol (4) and dibutyl phthalate (5), were isolated from the EtOH extract of L. japonicus. All the chemical structures of the isolates were elucidated on the basis of 1D and 2D NMR analyses. Compounds 1 and 2 were new terpenoids, and Compounds 3 and 4 were isolated and identified for the first time from this plant. In addition, the α-glucosidase and tyrosinase inhibitory activity of the new compounds were evaluated.

Isoleojaponin, a new Halimane diterpene isolated from Leonurus japonicus

Leojaponin (2), a labdane diterpene, was isolated from the EtOH extract of the herb of Leonurus japonicus together with a new halimane diterpene named isoleojaponin (1). Isoleojaponin has a new diterpene skeleton with a unique cross-conjugated α,β-unsaturated ketone system, Their structures were elucidated by physical and spectroscopic analysis, and the relative configuration of the chiral C-9 carbon was determined by a computational method, and analysis of its possible biogenesis pathways.

Leonurus japonicus Houtt.: ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Leonurus japonicus Houtt. (Labiatae), commonly called Chinese motherwort ([Symbol: see text]), is an herbaceous flowering plant native to Asia. For thousands of years in China, the aerial part of Leonurus japonicus has been used to treat menoxenia, dysmenorrhea, amenorrhea, lochia, edema of the body, oliguresis, sores, ulcerations and other diseases in women. Now, Leonurus japonicus is listed in the Pharmacopoeia of the People's Republic of China. The present paper reviewed the ethnopharmacology, phytochemistry, biological actions and toxicology of Leonurus japonicus.

MATERIALS AND METHODS

Information on Leonurus japonicus was gathered via the Internet (using Elsevier, ACS, Medline Plus, CNKI, VIP, Web of Science, Google Scholar and Baidu Scholar) and libraries.

RESULTS

Approximately 140 chemical compounds have been isolated from Leonurus japonicus, and the major components have been determined to be alkaloids, diterpenes and flavones. Among these active compounds, the effects of leonurine and stachydrine have been widely investigated. The primary active components in Leonurus japonicus possess wide pharmacological actions, such as effects on the uterus as well as cardioprotective, anti-oxidative, neuroprotective and anti-cancer activities.

CONCLUSIONS

Modern pharmacological studies have demonstrated that Leonurus japonicus has marked bioactivities, especially on the uterus and as a cardioprotective agent. These activities are related to its traditional use and provide prospects for the development of novel drugs, therapeutics and health care products for women. However, the toxicity of Leonurus japonicus will require further study, and the nomenclature for Leonurus japonicus will require additional clarification.