[Eleven new sesquiterpenoids from peeled stems of Syringa pinnatifolia].

The peeled stems of Syringa pinnatifolia(SP) is a representative Mongolian folk medicine with the effects of anti-depression, heat clearance, pain relief, and respiration improvement. It has been clinically used for the treatment of coronary heart disease, insomnia, asthma, and other cardiopulmonary diseases. As part of the systematic study on pharmacological substances of SP, 11 new sesquiterpenoids were isolated from the terpene-containing fractions of the ethanol extract of SP by liquid chromatography-mass spectrometry(LC-MS) and proton nuclear magnetic resonance(~1H-NMR) guided isolation methods. The planar structures of the sesquiterpenoids were identified by MS, 1D NMR, and 2D NMR data analysis, and were named pinnatanoids C and D(1 and 2), and alashanoids T-ZI(3-11), respectively. The structure types of the sesquiterpenoids included pinnatane, humulane, seco-humulane, guaiane, carryophyllane, seco-erimolphane, isodaucane, and other types. However, limited to the low content of compounds, the existence of multiple chiral centers, the flexibility of the structure, or lack of ultraviolet absorption, the stereoscopic configuration remained unresolved. The discovery of various sesquiterpenoids enriches the understanding of the chemical composition of the genus and species and provides references for further analysis of pharmacological substances of SP.

[Analysis of bacterial community structure and diversity during mountain-agarwood formation].

As an important substitute for agarwood, mountain-agarwood, belonging to the family Oleaceae, comes from the root, stem and thick branch of Syringa pinnatifolia, which has a wide range of application in Inner Mongolia, China. It has good clinical efficacy in the use of cardiovascular diseases. However, the formation speed of mountain-agarwood is extremely slow, and its cultivated seedlings have low resin content. Therefore, how to speed up the formation of mountain-agarwood and increase the resin content is a hot research topic in this field. In this work, 16 S rDNA amplicon sequencing method was used to systematically analyze the bacterial communities of different samples of mountain-agarwood. Our data revealed that the samples of mountain-agarwood had more obvious species diversity than the ones of non-mountain-agarwood, especially the wild mountain-agarwood samples. By analysis of bacterial community composition and species abundance, Sphingomonas, Modestobacter and unidentified Cyanobacteria genus were three dominant bacterial genera in all samples. In addition, there are two identified genera of dominant bacteria, namely Actinoplanes and Microbacterium in both wild and cultivated mountain-agarwood, by bacterial community composition and species richness analysis. Meanwhile, Roseomonas was the dominant bacterial genus in both wild and cultivated non-mountain-agarwood samples. Our work could provides basic data for exploring the mechanism of the mountain-agarwood formation, and help to exploit resource of endophytic bacteria reasonably.

[Microscopic histochemical comparison during mountain-agarwood formation].

Mountain-agarwood plays an important role in ethnic medicine in China for its pharmaceutical value. Modern pharmacological researches demonstrated that mountain-agarwood was effective for its anti-myocardial ischemia, antibacterial, anti-inflammatory, antitumor and analgesic effects. Mountain-agarwood derives from the peeled roots, stems or twigs of Syringa pinnatifolia which belongs to Syringa genus. It often depends on the purple substance and fragrance to estimate the formation of mountain-agarwood. However, the mechanism of mountain-agarwood formation has not been reported. To observe the microcosmic change in the process during the formation of mountain-agarwood, this study described the microscopic and histochemical characteristics of mountain-agarwood formation through histochemical staining. Our results showed that a significant difference of the distribution of tyloses existed during mountain-agarwood formation. It was observed that inchoate mountain-agarwood had more starch granules and viable cells than mountain-agarwood formed with high level or low level. The amount of polysaccharide and degree of lignification were increased during the mountain-agarwood formation. The results indicated that the mountain-agarwood, which meets the quality requirements for pharmaceutical use, contained the following characteristics: a large amount of purple tyloses in heartwood; yellow-brown tyloses distributing in heartwood and sapwood which were less in the latter; lignification with high level; a few viable cells; lots of polysaccharide and few starch granules in xylem rays cell. This study is aimed to reveal the change of histochemical characteristics during mountain-agarwood formation, and lay the foundation for exploring the mechanism of mountain-agarwood formation.

Alashanoids K-M, bioactive eremophilane sesquiterpenoids from Syringa pinnatifolia.

Three new eremophilane-type sesquiterpenoids, alashanoids K-M (1-3), and one known analogue (4) were isolated from the peeled stems of Syringa pinnatifolia. All the compounds were isolated from the genus Syringa for the first time. Structures of these compounds were established using 1D and 2D NMR and MS data. The absolute configurations were determined by experimental and calculated electronic circular dichroism analysis, a modification of Mosher's method, and X-ray diffraction. Compounds 2 and 3 inhibited NO production in LPS-induced RAW264.7 macrophage cells with IC50 values of 14.23 and 12.20 µM, respectively, and showed cytotoxic activities against HepG2 cells with the IC50 values of 34.41 and 40.86 µM, respectively.

[Pharmacological evaluation of Mongolian medicine Syringa pinnatifolia fraction I against acute myocardial ischemia in mice].

Syringa pinnatifolia Hemsl.( SP) is a representative Mongolian folk medicine with the effects of inhibiting Heyi related diseases,clearing heat and relieving pain. It has been used for the treatment of Heyi-induced heart tingling,heart palpitations,upset,insomnia and other symptoms. Total ethanol extract( T) and major fraction( M) of SP have been evaluated its anti-ischemic effects,and the mechanism was related to the regulation of cyclooxygenase( COX)-mediated inflammatory pathway and p53-mediated apoptosis pathway in our previous studies. This study reports the chemical fractionation on M by which to obtain subfractions( I and M_3),and the pharmacological evaluation of M,I,and M_3 against myocardial ischemia in mice. The result showed that I and M reduced the values of LVEDd and LVEDs,significantly increased EF and FS values,increased serum CK-MB and LDH levels in mice,and reduced in inflammatory cells infiltration and collagen deposition in the infarcted myocardial tissue,suggesting that M and I possess the same degree anti-myocardial is chemia equally whereas M_3 has no this effect. Related mechanism studies suggested that I can reduce the expression of COX-1,COX-2 and p53 protein in myocardial tissue in a dose-dependent manner. This study lays the foundation for further chemical segmentation and clarification of pharmacological substance groups,paving the way for the full use and benefits to be use of systematic biological methods to analyze the pharmacological basis of SP against myocardial ischemia.

[A new lignan from stem bark of Syringa pinnatifolia].

One new lignan, named Z-pinnatifolin A, along with ten known analogues, were isolated from the stem bark of Syringa pinnatifolia by various chromatographic methods. Their structures were extensively determined on basis of MS and NMR spectroscopic data analyses, and comparison with those in literature. Among them, compounds 3,4, and 8-11 were isolated from this genus for the first time, and 5-7 were isolated from the specie for the first time. Compound 1 showed a moderate inhibition on NO production in BV-2 cells. The present study provides a preliminary data for clarification of bioactive ingredients of S.pinnatifolia with anti-myocardial ischemic effect.

[Iridoids from stem bark of Syringa pinnatifolia].

One new iridoid, named alashanidoid A, and five known analogues, were isolated from the stem bark of Syringa pinnatifolia by various chromatographic methods. Their structures were determined on the basis of MS and NMR spectroscopic data analyses, and comparison with those in literature. Among them, compounds 3-5 were isolated from this genus for the first time, and 2 and 6 were isolated from the species for the first time.These isolates were tested for their in vitro anti-inflammatory activities against NO production in lipopolysaccharide(LPS)-induced RAW264.7 macrophages in mice and cytotoxicity of HepG2 cell line, however, no obvious activity was observed at the concentration of 40 µmol•L⁻¹.

[Phytochemical and pharmacological progress on peeled stem of Syringa pinnatifolia, a Mongolian folk medicine].

The peeled stem of Syringa pinnatifolia is a Mongolia folk medicine, mainly distributed in Helan mountain, inner Mongolia and Ningxia provinces of China. It has been used for the treatment of cardiopalmus, angina pectoris, and cardiopulmonary diseases for a long history. Contemporary research revealed the presence of major lignans, sesquitepenes, and essential oils, and showed myocardial ischemia related diseases. This review summarizes the plant origins, taxonomic disputes, phytochemical and pharmacological research progress, hopefully to provide reference for full medicinal utilization, clarification of biological effective substance, and drug development.