Dimeric eremophilane-type sesquiterpenoids from the peeled stems of Syringa pinnatifolia.

A continued phytochemical investigation guided by 1H NMR and LC-MS data on the ethanol extract from the peeled stems of Syringa pinnatifolia Hemsl. led to the isolation of 16 undescribed dimeric eremophilane sesquiterpenoids, namely syringenes R-Z (1-9) and A1-G1 (10-16). These structures were elucidated by extensive analysis of spectroscopic data, including HRESIMS, NMR, quantum-mechanics-based computational analysis of NMR chemical shifts, and single-crystal X-ray diffraction analyses, and a concise rule for determination of relative configuration of angular methyl was proposed. The results of the cardioprotective assay demonstrated that 3 exhibits a protective effect against hypoxia-induced injuries in H9c2 cells. This effect was observed at a concentration of 10 µM, with a protective rate of 28.43 ± 11.80%.

9,9'-epoxylignans from Syringa pinnatifolia: A typical case of stereochemical assignment by a quantum chemical calculation with MAEΔΔδ parameter.

In the current study, twenty-two stereochemical 9,9'-epoxylignans including 19 undescribed ones were isolated from the ethanol extract of Syringa pinnatifolia in our continuing effort to understand the overall chemical spectrum of this species. These isolates were structurally elucidated by extensive spectroscopic data analysis, X-ray diffraction, modified Mosher's method, and quantum chemical calculations. Meanwhile, the utilization of 13C NMR calculation and the MAEΔΔδ parameter facilitated the stereochemical assignment of groups of lignan stereoisomers. The 13C NMR data were corrected by the averaged errors at each corresponding carbon position in groups of lignan stereoisomers, which improved the theoretic 13C NMR calculation. The finding of the stereochemical structures of 9,9'-epoxylignans is significant. It is helpful to determine the absolute configurations of molecules with the similar core. In addition, these lignans exhibited potential cardioprotective activities on H9c2 cardiomyocytes in vitro and presented significant antioxidant effect.

The antioxidant, anti-inflammatory and analgesic activity effect of ethyl acetate extract from the flowers of Syringa pubescens Turcz.

ETHNOPHARMACOLOGICAL RELEVANCE: Syringa Pubescens Turcz. (SP), a member of the Oleaceae family, is a species of plant known as Syringa. Flowers, as the medicinal part, are commonly used in the treatment of hepatitis and tonsillitis. AIM OF THE STUDY: The research was the first to assess the antioxidant and anti-inflammatory potential of different parts of SP flowers (SPF) in vitro. The most promising fraction was ethyl acetate fraction of SP flower (SPFEA). The antioxidant, anti-inflammatory and analgesic activities of SPFEA were further studied, and the chemical components were identified. METHODS: HPLC was used to identify the major components in various fraction of SPF. DPPH and ABTS + radical scavenging assays as well as FRAP test and ß-carotene bleaching test were employed to assess the antioxidant potential of SPF fraction in vitro. The inhibitory effect on NO production in LPS-treated RAW264.7 cells and heat-induced protein denaturation test were used to evaluate the anti-inflammatory potential of SPF fraction. Further analysis of the biological activity of SPFEA was performed. Acute toxicity test was conducted to assess the toxicity of SPFEA. The anti-inflammatory effect was assessed by utilizing xylene induced ear edema model, carrageenan-induced foot edema model and peritonitis model in vivo. The analgesic effect of SPFEA was evaluated using hot plate test, tail immersion test, formaldehyde test as well as acetic acid-induced abdominal writhing pain experiment in vivo. In carrageenan induced foot edema model, ELISA kits were employed to measure levels of inflammation factors (NO, TNF-α, IL-6, COX-2, IL-1ß) in foot tissue as well as MDA, CAT, SOD, GSH-PX levels in liver tissue. RESULTS: HPLC results showed that there were significant differences in bioactive substances among different fractions of SPF, and SPFEA was rich in bioacitve components. Compared with other fractions of SPF, SPFEA exhibited better antioxidant and anti-inflammatory abilities. The 3000 mg/kg SPFEA group in mice had no obvious side effects. The xylene-induced ear edema model, carrageenan-induced foot edema and peritonitis models demonstrated that the SPFEA had significant anti-inflammatory effect. Moreover, inflammation factors including NO, TNF-α, IL-6, COX-2, IL-1ß were significantly reduced in SPFEA groups in foot tissue induced by carrageenan. Additionally, SPFEA effectively decreased liver tissue oxidative stress levels (MDA, SOD, GSH-PX and CAT). The bioactivities of SPFEA demonstrated a clear dose-dependent relationship. The results of the hot plate test, tail immersion test, formaldehyde test and acetic acid-induced abdominal writhing pain experiments indicated the SPFEA possessed an excellent analgesic effect, and this effect was in dose-dependent manner. CONCLUSION: The study provides a scientific foundation for understanding the pharmacological action of SPFEA. It has been indicated that SPFEA has excellent antioxidant, analgesic and anti-inflammatory effects.

Influence of Five Drying Methods on Active Compound Contents and Bioactivities of Fresh Flowers from Syringa pubescens Turcz.

The flower of Syringa pubescens Turcz. is used in Chinese folk medicine and also as a flower tea for healthcare. The effects of five drying methods on the active compound contents, the antioxidant abilities, anti-inflammatory properties and enzyme inhibitory activities were evaluated. The plant materials were treated using shade-drying, microwave-drying, sun-drying, infrared-drying and oven-drying. The seven active compounds were simultaneously determined using an HPLC method. Furthermore, the chemical profile was assessed using scanning electron microscopy, ultraviolet spectroscopy and infrared spectroscopy. The antioxidant capacities and protective effects on L02 cells induced with hydrogen peroxide were measured. The anti-inflammatory effects on lipopolysaccharide-induced RAW264.7 cells were investigated. The enzyme inhibitory activities were determined against α-amylase, α-glucosidase cholinesterases and tyrosinase. The results indicated that drying methods had significant influences on the active compound contents and biological properties. Compared with other samples, the OD samples possessed low IC50 values with 0.118 ± 0.004 mg/mL for DPPH radical, 1.538 ± 0.0972 for hydroxyl radical and 0.886 ± 0.199 mg/mL for superoxide radical, while the SHD samples had stronger reducing power compared with other samples. The SHD samples could be effective against H2O2-induced injury on L02 cells by the promoting of T-AOC, GSH-PX, SOD and CAT activities and the reducing of MDA content compared with other samples. Furthermore, SPF samples, especially the SHD sample, could evidently ameliorate inflammation through the inhibition of IL-6, IL-1ß and TNF-α expression. All the studied SPF samples exhibited evidently inhibitory effects on the four enzymes. The IC50 values of inhibitory activity on α-glucosidase and α-amylase from SHD sample were 2.516 ± 0.024 and 0.734 ± 0.034 mg/mL, respectively. SD samples had potential inhibitory effects on cholinesterases and tyrosinase with IC50 values of 3.443 ± 0.060 and 1.732 ± 0.058 mg/mL. In consideration of active compound contents and biological activities, it was recommended that SHD and SD be applied for drying SPF at an industrial scale.

Phenolic Compounds and Organic Acid Composition of Syringa vulgaris L. Flowers and Infusions.

The study aimed to determine the content of phenolic compounds (phenolic acids and flavonoids) and organic acids in dried flowers and water infusions of non-oxidised and oxidised flowers from four lilac cultivars. The diversity in the total phenolic and flavonoid content was in the flowers (18.35-67.14 and 2.03-2.65 mg g-1 DW, respectively) and infusions (14.72-47.78 and 0.20-1.84 mg per 100 mL infusion, respectively) depending the flower colour and form (oxidised and non-oxidised). Phenolic compounds and organic acids were susceptible to oxidation. Compared to infusions, flowers had more phenolic compounds and organic acids. The highest content of most phenolic compounds was confirmed for non-oxidised purple flowers (up to 7825.9 µg g-1 DW for chlorogenic acid) while in infusions for non-oxidised white flowers (up to 667.1 µg per 100 mL infusions for vanillic acid). The phenolic profile of the infusions was less diverse than that of flowers. The scavenging ability ranged from 52 to 87%. The highest organic acid content in flowers was for oxidised blue and purple flowers (2528.1 and 2479.0 µg g-1 DW, respectively) while in infusions the highest organic acid content was for oxidised purple flowers (550.1 µg per 100 mL infusions).

Alashanines A-C, Three Quinone-Terpenoid Alkaloids from Syringa pinnatifolia with Cytotoxic Potential by Activation of ERK.

Three quinone-terpenoid alkaloids, alashanines A-C (1-3), possessing an unprecedented 6/6/6 tricyclic conjugated backbone and quinone-quinoline-fused characteristic, were isolated from the peeled stems of Syringa pinnatifolia. Their structures were elucidated by analysis of extensive spectroscopic data and quantum chemical calculations. A hypothesis of biosynthesis pathways for 1-3 was proposed on the basis of the potential precursor iridoid and benzoquinone. Compound 1 exhibited antibacterial activities against Bacillus subtilis and cytotoxicity against HepG2 and MCF-7 human cancer cell lines. The results of the cytotoxic mechanism revealed that compound 1 induced apoptosis of HepG2 cells through activation of ERK.

Potential antioxidative components from Syringa oblata Lindl stems revealed by affinity ultrafiltration with multiple drug targets.

Traditional Chinese medicine is the main source of natural products due to its remarkable clinical efficacy. Syringa oblata Lindl (S. oblata) was widely used because of its extensive biological activities. However, to explore the antioxidant components of S. oblata against tyrosinase, the experiments of antioxidation in vitro were employed. At the same time, the determination of TPC was also use to assess the antioxidant ability of CE, MC, EA and WA fractions and the liver protective activity of the EA fraction was evaluated by mice in vivo. Next, UF-LC-MS technology was performed to screen and identify the efficient tyrosinase inhibitors in S. oblata. The results showed that alashinol (G), dihydrocubebin, syripinin E and secoisolariciresinol were characterized as potential tyrosinase ligands and their RBA values were 2.35, 1.97, 1.91 and 1.61, respectively. Moreover, these four ligands can effectively dock with tyrosinase molecules, with binding energies (BEs) ranging from 0.74 to -0.73 kcal/mol. In addition, tyrosinase inhibition experiment was employed to evaluate the tyrosinase inhibition activities of four potential ligands, the result showed that compound 12 (alashinol G, IC50 = 0.91 ± 0.20 mM) showed the strongest activity to tyrosinase, followed by secoisolariciresinol (IC50 = 0.99 ± 0.07 mM), dihydrocubebin (IC50 = 1.04 ± 0.30 mM) and syripinin E (IC50 = 1.28 ± 0.23 mM), respectively. The results demonstrate that S. oblata might have excellent antioxidant activity, and UF-LC-MS technique is a effective means to filter out tyrosinase inhibitors from natural products.

Volatile secondary metabolome and transcriptome analysis reveals distinct regulation mechanism of aroma biosynthesis in Syringa oblata and S. vulgaris.

Lilacs have high ornamental value due to their strong aroma. However, the molecular regulatory mechanisms of aroma biosynthesis and metabolism in lilac were largely unclear. In this study, two varieties with distinct aroma, Syringa oblata 'Zi Kui' (faint aroma) and Syringa vulgaris 'Li Fei' (strong aroma), were used for exploring the regulation mechanism of aroma difference. Via GC-MS analysis, a total of 43 volatile components were identified. Terpene volatiles was the most abundant volatiles constituting the aroma of two varieties. Notably, 3 volatile secondary metabolites were unique in 'Zi Kui' and 30 volatile secondary metabolites were unique in 'Li Fei'. Then, a transcriptome analysis was performed to clarify the regulation mechanism of aroma metabolism difference between these two varieties, and identified 6411 differentially expressed genes (DEGs). Interestingly, ubiquinone and other terpenoid-quinone biosynthesis genes were significantly enriched in DEGs. We further conducted a correlation analysis between the volatile metabolome and transcriptome and found that TPS, GGPPS, and HMGS genes might be the key contributors to the differences in floral fragrance composition between the two lilac varieties. Our study improves the understanding in the regulation mechanism of Lilac aroma and would help improve the aroma of ornamental crops by metabolic engineering.

[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.

The Effect and Mechanism of Syringa pinnatifolia Hemsl. Ligans on Cerebral Ischemia-Reperfusion Injury and Oxidative Stress in Mice.

Lignans are the main components of Syringa pinnatifolia Hemsl. (SP). Previous studies have shown that SP lignans (SPL) can considerably improve CCl4-induced acute liver injury in mice by the anti-oxidative stress (OS) mechanism. In this study, we investigated the antioxidant effects of SPL on cerebral ischemia/reperfusion injury (CIRI) and its underlying molecular mechanism. We developed a middle cerebral artery occlusion/reperfusion (MCAO/R) model in mice to achieve CIRI and orally administered SPL daily for 1-3 days. We evaluated neurological function deficits and performed hematoxylin and eosin staining. We further calculated the infarct volume. Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in the brain were detected using corresponding kits. The transcription and protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), and NAD(P)H quinone dehydrogenase 1 (NQO1) in brain tissues were analyzed by real-time reverse transcription polymerase chain reaction and western blotting, respectively. The results showed that SPL could remarkably ameliorate neurological functions and pathological damage in brain tissues, reducing the cerebral infarct volume. It also increased the SOD and GPx activities decreased the MDA levels as well as inhibited the expression of (NOX)2 and NOX4. We also found that the mRNA and protein levels of Nrf2, HO-1, and NQO1 in the CIRI mice increased transiently and peaked at 24 h of reperfusion, and then began to decline. SPL could reverse decreasing Nrf2 and HO-1 levels after 24 h. In conclusion, SPL can alleviate CIRI and OS by activating the Nrf2/HO-1 pathway.

Zerumbone, a major sesquiterpene from Syringa pinnatifolia Hemsl., exerts the sedative effect by regulating GABAergic nervous system.

ETHNOPHARMACOLOGICAL RELEVANCE: Zerumbone (ZER) is a humulane sesquiterpenoid isolated from Syringa pinnatifolia Hemsl. (SP), its content accounts for 64.7% of volatile oil and 0.86% of total ethanol extract (TEE), representing one of characteristic ingredient of SP. As a representative Mongolian medicine with anti-"Khii", anti-asthma, and clearing-heat effects, SP has been used for the treatment of cardiovascular diseases, upset, insomnia, and other symptoms. AIM OF STUDY: Previous results showed that TEE has sedative effect, but the pharmacological substances and its sedative mechanism remains unclear. This study aims to determine whether ZER, as one of major and characteristic sesquiterpenoids of SP, contributes to the sedative effect of SP and its underlying mechanism. MATERIALS AND METHODS: Locomotor activity and threshold dose of pentobarbital sodium sleep experiments were used to evaluate the sedative effects in mice. ELISA assay was used to examine the level of GABA/Glu ratio in rats hippocampus, cortex and hypothalamus tissue. The binding ability of ZER with glutamic acid decarboxylase 67 (GAD67) and Gephyrin protein were predicted by molecular docking. Western blot and Immunohistochemistry assay were used to determine the expression of GABAergic nerve system related proteins (GAD67, Gephyrin) in rat's hypothalamus. ZER was co-administrated with flumazenil and bicuculline (GABAA antagonist) to determine whether it acts on GABAA receptor. Furthermore, MQAE assay was used to test the effect of ZER on the chloride ion concentration in cerebellar granule cells. RESULTS: Current data demonstrated that ZER dose-dependently (5-20 mg/kg) reduces the locomotor activity and sleep latency of mice, and extend sleeping time of mice. The results of ELISA showed that ZER increases the level of GABA/Glu in rats brain tissue, in particular in hypothalamus. Molecular docking results revealed that ZER has a strong affinity to GAD67 and Gephyrin protein. The Western blot and Immunohistochemistry data indicated that ZER up-regulates the expression of GAD67 and Gephyrin protein in rat's hypothalamus. Antagonism test results demonstrated that flumazenil and bicuculline reverse the effect of ZER on threshold dose of pentobarbital sodium sleep experiments. In addition, ZER also could dose-dependently (5-20 µM) increase the chloride ion concentration in cerebellar granule cell, suggesting that ZER induces the opening of chloride channel, exerts central inhibitory effect. CONCLUSION: ZER has a significant sedative effect in mice and rat, and the effect is associated with GABAergic nervous system. The present results suggest that ZER, as one of the major bioactive ingredients of SP, contributes to the sedative effect and provide substantial evidence for its traditional use of anti-"Khii" in clinic of Syringa pinnatifolia.

Diverse lignans with protective effect against hypoxia/oxidative injuries to H9c2 cells from Syringa pinnatifolia Hemsl.

A bioactivity-guided fractionation on the phenolic fractions from the peeled stems of Syringa pinnatifolia Hemsl., one of representative Mongolian folk medicine in China, led to the isolation and structural determination of 11 undescribed lignans and 12 known ones. These lignans cover diverse types, among them syringanones A and B represent an unprecedented carbon skeleton (proposed syringanane) and alashanenol A possesses a rare bicyclo [3.3.1]nonadienemethanol core. Their structures were established by extensive spectroscopic data analysis, X-ray diffraction, and quantum chemical calculations. All isolates were evaluated for their cardioprotective activities on H9c2 cardiomyocytes in vitro. The results showed that five lignans exhibited the protective effects against hypoxia-induced injury at the concentrations of 1.2-40 µM and six lignans exhibited anti-oxidative stress injury at 10-40 µM. These findings account to some extend for the traditional therapeutic effects of S. pinnatifolia for the treatment of ischemic heart diseases in clinic.

Simultaneous Determination of Phenylethanoid Glycosides and Antioxidant Activity of Syringa pubescens Turcz. from Different Geographical Origin in China.

A high-performance liquid chromatograph with diode array detector was established for the simultaneous determination of five phenylethanoid glycosides in Syringa pubescens Turcz. The optimal chromatographic conditions were achieved on a Zorbax C18 column using gradient elution with 0.5% aqueous acetic acid and acetonitrile as the mobile phase at the flow rate of 1.0 mL/min. The detection wavelength was developed as follows: 0-10 min, 276 nm; 10-45 min, 332 nm. The validation of the method including linearity, precision, stability, accuracy, repeatability and recovery was tested. The chemometric analysis including hierarchical cluster analysis and principal component analysis was employed to investigate the similarity and difference of samples from different geographical origin. The results revealed that S. pubescens samples were divided into four clusters based on the phenylethanoid glycosides contents. Antioxidant activity of extract was measured using three different methods including α,α-diphenyl-ß-picrylhydrazyl and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical scavenging assays, and ferric reducing antioxidant power assay. Furthermore, different phenylethanoid glycosides exhibited different contribution to antioxidant capacities. This study provides a foundation for the quality evaluation and offers scientific data for the utilization of S. pubescens resources.

Analysis of the chloroplast genome and phylogenetic evolution of three species of Syringa.

BACKGROUND: By the time our study was completed, the chloroplast genomes of Syringa oblata, S. pubescents subsp. Microphylla, and S. reticulate subsp. Amurensis had not been sequenced, and their genetic background was not clear. THE RESEARCH CONTENT: In this study, the chloroplast genomes of Syringa oblata, S. pubescents subsp. Microphylla, S. reticulate subsp. Amurensis, and five other species of Syringa were sequenced for a comparative genomics analysis, inverted repeat (IR) boundary analysis, collinearity analysis, codon preference analysis and a nucleotide variability analysis. Differences in the complete chloroplast genomes of 30 species of Oleaceae were compared with that of S. oblata as the reference species, and Ginkgo biloba was used as the out group to construct the phylogenetic tree. RESULTS: The results showed that the chloroplast genomes of S. oblata, S. pubescents subsp. Microphylla, and S. reticulate subsp. Amurensis were similar to those of other angiosperms and showed a typical four-segment structure, with full lengths of 155,569, 160,491, 155,419, and protein codes of 88, 95, and 87, respectively. Because the IR boundary of S. pubescents subsp. Microphylla was significantly expanded to the large single copy (LSC) region, resulting in complete replication of some genes in the IR region, the LSC region of S. pubescents subsp. Microphylla was significantly shorter than those of S. oblate and S. reticulate subsp. Amurensis. Similar to most higher plants, these three species have a preference for their codons ending with A/T. CONCLUSIONS: We consider the genus Syringa to be a synphyletic group. The nucleotide variability and phylogenetic analyses showed that Syringa differentiated before Ligustrum and Ligustrum developed from Syringa. We propose removing the existing section division and directly dividing Syringa into five series.

The Ethanol Extract of Syringa oblata Heartwood, a Mongolian Folk Medicine Containing Major Lignans, Exerts Analgesic and Sedative Effects on Mice.

The heartwood of Syringa oblata Lindl. (SO) is one of Mongolian folk medicines to treat insomnia and pain, while its pharmacological evaluation and underlying mechanism remain unclear. In this study, the sedative effect of ethanol extract of SO (ESO) was evaluated with the locomotor activity test and the threshold dose of pentobarbital sodium-induced sleep test in mice, and the hot plate test, acetic acid-induced writhing test, and formalin test in mice were used to evaluate its analgesic effect. The underlying mechanism of ESO analgesia was explored by RT-PCR and western blot analysis, which is associated with the regulation of the NF-κB signaling pathway. Besides, the main constituents of ESO were characterized by LC/MS data analysis and comparison with isolated pure compounds. The current findings brought evidence for clinical application and further pharmacological and phytochemical studies on SO.

Eleven new sesquiterpenoids from peeled stems of Syringa pinnatifolia / 中国中药杂志

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.

Establishment of fingerprint and mechanism of anti-myocardial ischemic effect of Syringa pinnatifolia.

This study established the fingerprint of Syringa pinnatifolia Hemsl. (SP), analyzed the SP ingredients absorbed into the rats blood, and evaluated its anti-myocardial ischemic effect to provide a scientific basis for the follow-up development and research of SP and lay a foundation for its clinical application using ultra-performance liquid chromatography-Q Exactive-mass spectrometry and GC-MS. Myocardial infarction was induced in rat by ligating the left anterior descending branch of the rat coronary artery, and SP alcohol extract was administered to evaluate its anti-myocardial ischemic effect. We analyzed the SP ingredients absorbed into the rats blood, screened the active compounds, established a database of SP anti-myocardial ischemic targets, and explored the possible mechanism of SP in treating myocardial infarction using bioinformatics. The rats were examined using echocardiography, serum biomarkers were determined, and pathological changes were observed by histopathological examination. TUNEL staining was performed to detect the apoptotic level of cells, and Western blot and quantitative real-time polymerase chain reaction were performed to detect the expression levels of Bcl-2, Bax, and Caspase-3 in heart tissues. In the fingerprint of SP, 24 common peaks were established, and the similarity evaluation results of 10 batches of SP were all >0.9. Ultra-performance liquid chromatography-Q Exactive-mass spectrometry and GC-MS detected 17 active ingredients in the drug-containing serum, including terpenoids, flavonoids, phenols, phenylpropanoids, and phenolic acids, the most abundant of which was resveratrol. Enrichment analysis of SP targets against myocardial ischemia revealed that key candidate targets of SP were significantly enriched in multiple pathways associated with apoptosis. Resveratrol was administered to the successfully modeled rats, and the results showed that the resveratrol group significantly decreased left ventricular end-diastolic diameter and left ventricular end-systolic diameter and significantly increased ejection fraction and fractional shortening in all groups compared with the model group. Resveratrol significantly decreased the levels of creatine kinase isoenzyme and lactate dehydrogenase in serum compared to the model group (P < 0.001). Hematoxylin-eosin staining of rat myocardial tissue showed that all lesions were reduced under microscopic observation in the resveratrol group compared with the model group. Real-time polymerase chain reaction and Western blot results showed that the resveratrol group downregulated the expression of the proapoptotic factor Bax, upregulated the expression of the antiapoptotic factor Bcl-2, and decreased the expression of Caspase-3. The established fingerprints are accurate, reliable, and reproducible and can be used as an effective method for quality control of the herbs. The anti-myocardial ischemia effect of SP is that resveratrol improves cardiac function and inhibits cardiomyocyte apoptosis to protect cardiomyocytes. The present study provides ample evidence for the clinical use of SP, suggesting that this drug has great potential in the treatment of ischemic heart disease.

Identification and phylogenetic analysis of the genus Syringa based on chloroplast genomic DNA barcoding.

DNA barcoding is a supplementary tool in plant systematics that is extensively used to resolve species-level controversies. This study assesses the significance of using two DNA barcoding loci (e.g., psbA-trnH and trnC-petN) in distinguishing 33 plant samples of the genus Syringa. Results showed that the average genetic distance K2P of psbA-trnH DNA marker was 0.0521, which is much higher than that of trnC-petN, which is 0.0171. A neighbor-joining phylogenetic tree based on psbA-trnH and trnC-petN indicated that the identification rate of psbA-trnH and trnC-petN alone were 75% and 62.5%, respectively. The barcode combination of psbA-trnH+trnC-petN could identify 33 samples of the genus Syringa accurately and effectively with an identification rate of 87.5%. The 33 Syringa samples were divided into four groups: Group I is series Syringa represented by Syringa oblata; Group II is series Villosae represented by Syringa villosa; Group III is series Pubescentes represented by Syringa meyeri; and Group IV is section Ligustrina represented by Syringa reticulata subsp. pekinensis. These research results provided strong evidence that the combinatorial barcode of psbA-trnH+trnC-petN had high-efficiency identification ability and application prospects in species of the genus Syringa.

Lilac (Syringa oblata) genome provides insights into its evolution and molecular mechanism of petal color change.

Color change during flower opening is common; however, little is understood on the biochemical and molecular basis related. Lilac (Syringa oblata), a well-known woody ornamental plant with obvious petal color changes, is an ideal model. Here, we presented chromosome-scale genome assembly for lilac, resolved the flavonoids metabolism, and identified key genes and potential regulatory networks related to petal color change. The genome assembly is 1.05 Gb anchored onto 23 chromosomes, with a BUSCO score of 96.6%. Whole-genome duplication (WGD) event shared within Oleaceae was revealed. Metabolome quantification identified delphinidin-3-O-rutinoside (Dp3Ru) and cyanidin-3-O-rutinoside (Cy3Ru) as the major pigments; gene co-expression networks indicated WRKY an essential regulation factor at the early flowering stage, ERF more important in the color transition period (from violet to light nearly white), while the MBW complex participated in the entire process. Our results provide a foundation for functional study and molecular breeding in lilac.

A chromosome-level genome of Syringa oblata provides new insights into chromosome formation in Oleaceae and evolutionary history of lilacs.

Lilacs (Syringa L.), a group of well-known ornamental and aromatic woody plants, have long been used for gardening, essential oils and medicine purposes in East Asia and Europe. The lack of knowledge about the complete genome of Syringa not only hampers effort to better understand its evolutionary history, but also prevents genome-based functional gene mining that can help in the variety improvement and medicine development. Here, a chromosome-level genome of Syringa oblata is presented, which has a size of 1.12 Gb including 53 944 protein coding genes. Synteny analysis revealed that a recent duplication event and parallel evolution of two subgenomes formed the current karyotype. Evolutionary analysis, transcriptomics and metabolic profiling showed that segment and tandem duplications contributed to scent formation in the woody aromatic species. Moreover, phylogenetic analysis indicated that S. oblata shared a common ancestor with Osmanthus fragrans and Olea europaea approximately 27.61 million years ago (Mya). Biogeographic reconstruction based on a resequenced data set of 26 species suggested that Syringa originated in the northern part of East Asia during the Miocene (approximately 14.73 Mya) and that the five Syringa groups initially formed before the Late Miocene (approximately 9.97 Mya). Furthermore, multidirectional dispersals accompanied by gene introgression among Syringa species from Northern China during the Miocene were detected by biogeographic reconstruction. Taken together, the results showed that complex gene introgression, which occurred during speciation history, greatly contributed to Syringa diversity.