Sesquiterpene Alkaloids Research Articles

Chemical Screening, Identification, and Comparison of Tripterygium Hypoglaucum Hutch Preparations by Ultra-High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry Combined With Multivariate Statistical Analysis.

Colquhounia root tablets (CRT) and Tripterygium hypoglaucum hutch tablets (THHT), two major Tripterygium hypoglaucum hutch (THH) commercial preparations, have been used to treat chronic kidney diseases or rheumatic diseases. However, there have been no reports on the chemical comparison between CRT and THHT, greatly hindering the understanding of their pharmacological difference as well as their rational application in clinical practice. In the present study, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry combined with automated data analysis by MS-DIAL software and MS-FLO website was employed to systematically screen and characterize the components in CRT and THHT. Multivariate statistical analysis was used to compare the differences between these two preparations. As a result, up to 92 components were tentatively identified, and 17 of them were characterized for the first time in THH preparations. According to the criteria of variable importance in projection (VIP) >1, p < 0.05, and fold change (FC) > 1.2, 46 components could be screened as major differential chemical components. Among them, phenolic acids, organic acids, amino acids, and diterpenoids were higher in CRT, while the sesquiterpene alkaloids were relatively higher in THHT. This study clarified the chemical material basis and the difference between CRT and THHT, providing a valuable reference for quality control and clinical rational use of THH preparations.

Eurochevalierines A-I, Sesquiterpene Alkaloid Hybrids with Anti-Triple Negative Breast Cancer Activity from Penicillium sp. HZ-5.

Nine new sesquiterpene alkaloids, eurochevalierines A-I (1-9), were separated from the rice cultures of the endophytic fungus Penicillium sp. HZ-5 originated from the fresh leaf of Hypericum wilsonii N. Robson. The structures' illumination was conducted by single-crystal X-ray diffraction, extensive spectroscopic analysis, alkaline hydrolysis reaction, and Snatzke's method. Importantly, the antitumor activities screen of these isolates indicated that 1 could suppress triple negative breast cancer (TNBC) cell proliferation and induce apoptosis, with an IC50 value of 5.4 μM, which is comparable to the positive control docetaxel (DXT). Flow cytometry experiments mentioned that compound 1 significantly reduced mitochondrial membrane potential (MMP) of TNBC cells. In addition, 1 could activate caspase-3 and elevated the levels of reactive oxygen species (ROS) and expressions of suppressive cytokines and chemokines. Further Western blot analysis showed that 1 could selectively induce mitochondria-dependent apoptosis in TNBC cells via the BAX/BCL-2 pathway. Remarkably, these finding provide a new natural product skeleton for the treatment of TNBC.

Miliutine C methyl ester, a new drimane sesquiterpene and bioactive alkaloids from the stems of Miliusa velutina

Previous results from the our research group have isolated numerous compounds, including novel ones, but the anticancer activity of Miliusa velutina has not been demonstrated. In this study, from the most active ethyl acetate extract of the stems of Miliusa velutina, seven compounds were isolated and determined structures, including a new drimane sesquiterpenoid compound named miliutine C methyl ester (1) and three bioactive alkaloids (5-7). These three alkaloids (5-7) exhibited strong anticancer activities against various cancer cell lines such as MCF-7, HepG2, HeLa, NCI H460 and normal fibroblasts. Especially, on MCF-7 and normal fibroblasts with values of IC50 (μM) in order for compounds 5 (3.38, 31.15), 6 (21.96, 102.00), 7 (7.90, greater than 300), to compare with positive control camptothecin (0.020, 4.51); which is highly noteworthy. These results contribute to elucidating and confirming the value of Miliusa velutina, similar to other published and folkloric findings.

Metabolic Pathway Engineering Improves Dendrobine Production in Dendrobium catenatum.

The sesquiterpene alkaloid dendrobine, widely recognized as the main active compound and a quality control standard of medicinal orchids in the Chinese Pharmacopoeia, demonstrates diverse biological functions. In this study, we engineered Dendrobium catenatum as a chassis plant for the production of dendrobine through the screening and pyramiding of key biosynthesis genes. Initially, previously predicted upstream key genes in the methyl-D-erythritol 4-phosphate (MEP) pathway for dendrobine synthesis, including 4-(Cytidine 5'-Diphospho)-2-C-Methyl-d-Erythritol Kinase (CMK), 1-Deoxy-d-Xylulose 5-Phosphate Reductoisomerase (DXR), 2-C-Methyl-d-Erythritol 4-Phosphate Cytidylyltransferase (MCT), and Strictosidine Synthase 1 (STR1), and a few downstream post-modification genes, including Cytochrome P450 94C1 (CYP94C1), Branched-Chain-Amino-Acid Aminotransferase 2 (BCAT2), and Methyltransferase-like Protein 23 (METTL23), were chosen due to their deduced roles in enhancing dendrobine production. The seven genes (SG) were then stacked and transiently expressed in the leaves of D. catenatum, resulting in a dendrobine yield that was two-fold higher compared to that of the empty vector control (EV). Further, RNA-seq analysis identified Copper Methylamine Oxidase (CMEAO) as a strong candidate with predicted functions in the post-modification processes of alkaloid biosynthesis. Overexpression of CMEAO increased dendrobine content by two-fold. Additionally, co-expression analysis of the differentially expressed genes (DEGs) by weighted gene co-expression network analysis (WGCNA) retrieved one regulatory transcription factor gene MYB61. Overexpression of MYB61 increased dendrobine levels by more than two-fold in D. catenatum. In short, this work provides an efficient strategy and prospective candidates for the genetic engineering of D. catenatum to produce dendrobine, thereby improving its medicinal value.

Metabolic profiling, in-situ spatial distribution, and biosynthetic pathway of functional metabolites in Dendrobium nobile stem revealed by combining UPLC-QTOF-MS with MALDI-TOF-MSI.

The stem of Dendrobium nobile Lindl. (Orchidaceae), called "Shihu" in traditional Chinese medicine, is a well-known medicinal and edible plant material in China. It is used as an antipyretic, analgesic, and tonic to nourish the stomach and Yin (i.e., to improve the production of body fluids). These therapeutic properties are attributed to its alkaloids, sesquiterpenoids, bibenzyls, fluorenones, and phenanthrenes. However, a comprehensive understanding of these metabolites and their spatial distribution in stems is lacking. In this study, ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was performed to obtain detailed metabolites information about D. nobile stems. Then, the spatial distributions of diverse metabolites, including alkaloids and sesquiterpenoids, were characterized and visualized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF-MSI). Based on the spatial and metabolic profiling data, sesquiterpene alkaloid dendrobine was chosen for the exhaustive study of a biosynthetic pathway in D. nobile. This is the first report on mass spectrometry imaging for Dendrobium species. As a result, critical bioactive metabolites such as 11 alkaloids, 10 sesquiterpenes, and 13 other metabolites were putatively identified and relatively quantified. The identified alkaloids were distributed in the parenchyma or vascular bundle, and sesquiterpenes were present in all regions of the stem with higher abundance in the vascular bundle and cuticle, or in the cuticle and epidermis. The biosynthetic pathway and accumulation pattern of dendrobine in D. nobile stem were also proposed. Our findings not only provided a critical methodology for the thorough understanding of physiological changes in metabolites and precise utilization of D. nobile stem, but also displayed an effective strategy for insight into the biosynthesis of bioactive metabolites in plants.

Celastraceae sesquiterpene pyridyl ligands

Celastraceae sesquiterpene alkaloids display an array of biological properties and comprise oxygenated dihydroagarofuran cores often adorned with pyridyl macrodilactone bridging ligands. Here, the history and syntheses of these ligands are reviewed.

Histochemical Analysis of Aerial part of Dracocephalum ruyschiana L. and Dracocephalum nutans L. growing in the Territory of Central Kazakhstan

Histochemical analysis of medicinal plants and raw materials is intended to be used to study the localization of various chemical substances and products of their metabolism in tissues. The article presents the results of histochemical analysis of leaves, flowers and stems of Dracocephalum ruyschiana L. and Dracocephalum nutans L. The genus Dracocephalum L. belongs to the family Lamiaceae Lindl. (Labiatae), whose plants are of interest as sources for medicinal preparations. These two species of Dracocephalum are related to Dracocephalum moldavica L., used in folk medicine for respiratory diseases, as an antipyretic agent, for asthenia, as a potency-increasing agent. Studies have shown that some species of Dracocephalum have antibacterial, antitussive, antidiarrheal, antioxidant, anti-cancer, anti-inflammatory, anti-diabetic and sedative properties. To determine the localization features of certain groups of secondary metabolites in the aerial part of Dracocephalum ruyschiana L. and Dracocephalum nutans L. growing in the territory of Central Kazakhstan at the microscopic level. Materials and methods. Cross-sections of stems, flowers, and D. ruyschiana and D. nutans were fixed in Strauss-Fleming solution, after which histochemical reactions were carried out to locate and identify essential oils, phenolic acids, flavonoids, sesquiterpene lactones, polysaccharides and alkaloids. The study of microscopic features, as well as histochemical tests were carried out according to the methods of the State Pharmacopoeia of the Republic of Kazakhstan using a light microscope Biomed-4. Results and Discussion. The localization of biologically active substances in the studied plant raw materials was determined by histochemical methods using light microscopy. The presence of phenolic acids, flavonoids and essential oil was established. The absence of sesquiterpene lactones, polysaccharides and alkaloids in the studied raw materials was established. Conclusion. The localization of secondary metabolites was studied for the first time by histochemical tests in the tissues of D. ruyschiana and D. nutans. The results of histochemical studies can be used to confirm the authenticity, identification and standardization of the aerial parts of D. ruyschiana and D. nutans.

Comprehensive Evaluation of the Quality of Tripterygium Glycosides Tablets Based on Multi-Component Quantification Combined with an In Vitro Biological Assay.

Tripterygium glycosides tablets (TGTs) are widely used in clinical practice to treat rheumatoid arthritis and other autoimmune diseases, with significant beneficial effects but also high toxicity, necessitating rigorous quality evaluation and control. In current study, a rapid resolution liquid chromatography tandem electrospray ionization triple quadrupole mass spectrometry (RRLC–ESI–MS/MS) method was developed and validated for the quantitative analysis of 14 components of ten batches of TGTs produced by different manufacturers, including four diterpenoids, three triterpenoids, and seven sesquiterpene alkaloids. Meanwhile, the NO inhibition effects of these TGTs were evaluated in LPS-induced RAW264.7 cells for their downstream anti-inflammatory activities, as well as their cytotoxicity. The results indicate that the TGTs from different manufacturers showed poor quality consistency, as evidenced by large variations in chemical profiles and biological effects, which may increase the risks associated with clinical use. To improve the quality status of TGTs, it is crucial to identify indicator components whose characterization can accurately reflect the efficacy and toxicity of TGTs from which they were derived. Our study reveals that triptolide, triptoquinone B, celastrol, and demethylzelaysteral considerably contributed to the anti-inflammatory activity and/or cytotoxicity of TGTs, implying that they should be further investigated as candidate indicator components for TGT quality control.

Monoaminergic system involvement in the antidepressant-like and anxiolytic-like properties of novel β-dihydroagarofuran sesquiterpene alkaloid and triterpenes isolated from Gymnosporia heterophylla aerial parts in mice

Gymnosporia heterophylla (synonym Maytenus) is widely used in folk medicine for the treatment of various illness including neurological diseases. This study presents the antidepressant-like and anxiolytic-like effects of novel bioactive constituents; 3,4˗seco-1-hydroxy-21-oxoolean-3,11-olide (A2), 1β,2β-diacetoxy-9β-benzoyloxy-6α-nicotinoyloxy-β-dihydroagarofuran (A5) as well as known 3-acetoxy-1β-hydroxyLupe-20(29)-ene (selective COX-2; A4) from the aerial parts of G. heterophylla. The antidepressant-like effect was studied using the forced swim test (FST) while the elevated plus maze test (EPMT) and open field test (OFT) were employed for anxiolytic-like effect. Acute treatment with A4 and A5 (0.5, 5 or 10 mg/kg) significantly reduced the duration of immobility and immobile episodes with prolongation of immobility latency in the FST with peak effects observed at 10 and 0.5 mg/kg, respectively. Moreover, antidepressant-like effect of A4 and A5 were relatively better than that of fluoxetine. Conversely, the pretreatment of mice with prazosin (1 mg/kg, α1-adrenoceptor antagonist), yohimbine (1 mg/kg; α2-adrenoceptor antagonist), or sulpiride (50 mg/kg; dopamine D2-receptor antagonist) reversed antidepressant-like effect of A4 and A5 but not WAY 100635 (10 mg/kg, i.p., selective 5-HT1A receptor antagonist), GR 127935 (5 mg/kg, i.p., selective 5-HT1B receptor antagonist), metergoline (4 mg/kg, i.p, non-selective 5-HT2 receptor antagonist), ketanserin (5 mg/kg, i.p., a selective 5-HT2A receptor antagonist) or p-chlorophenylalanine (pCPA) (100 mg/kg, i.p., tryptophan hydroxylase inhibitor) in the FST. Interestingly, A2, A4 and A5 significantly increased the time spent in the open arms of the EPM suggestive of anxiolytic-like action. Findings from this study showed that the novel β-dihydroagarofuran sesquiterpene alkaloid and triterpenes possesses antidepressant-like and anxiolytic-like effects through enhancement of monoaminergic signaling.

Liriogerphines A-D, a Class of Sesquiterpene-Alkaloid Hybrids from the Rare Chinese Tulip Tree Plant.

Liriogerphines A-D (1-4, respectively), an unprecedented class of hybrids of germacranolide-type sesquiterpenoids and aporphine-type alkaloids, were isolated from the rare medicinal plant Liriodendron chinense. Their structures were elucidated by comprehensive spectroscopic analyses combined with electronic circular dichroism calculations and X-ray crystallographic data. Biosynthetically, an aza-Michael addition reaction is proposed to be involved in the assemblies of this class of hybrids. Compound 4 exhibited cytotoxicity against leukemia cells via inducing apoptosis and inhibiting Bcl-2 expression.

Identification and comparison of compounds in commercial Tripterygium wilfordii genus preparations with HPLC-QTOF/MS based on molecular networking and multivariate statistical analysis

Tripterygium wilfordii genus preparations (TWGP) are widely used in traditional Chinese medicines for the treatment of autoimmune diseases and immune diseases with definite therapeutic effects but high toxicity. The aim of this study is to identify and compare chemical compounds in three types of commercial TWGP using UHPLC-QTOF-MS/MS and molecular networking (MN) technology. First, the mass fragmentation pathways of 10 compounds were investigated, which included two sesquiterpene alkaloids, four diterpenoids, and four triterpenoids. The chemical compounds were then identified using UHPLC-QTOF-MS/MS and a conventional database. Following that, molecular network technology was used to further identify the GNPS platform. Finally, metabonomic data analysis was used to compare 92 commercial TWGP samples from 13 manufacturers. A total of 103 compounds were identified, with the molecular network detecting 40 of them. Moreover, the quality of commercial Tripterygium glycoside tablets varies greatly and 26 compounds, including triptolide, wilforine, wilforgine, and demethylzeylasteral, were discovered to be the main differential compounds in tripterygium glycosides tablets. This was the first time MN technology was used for compound analysis in TWGP, laying the foundation for classifying effective and toxic substances and TWGP quality control.

Mechanistic Insight into Binding of Huperzine A with Human Serum Albumin: Computational and Spectroscopic Approaches.

Human serum albumin (HSA) is the most abundant protein in plasma synthesized by the liver and the main modulator of fluid distribution between body compartments. It has an amazing capacity to bind with multiple ligands, offering a store and transporter for various endogenous and exogenous compounds. Huperzine A (HpzA) is a natural sesquiterpene alkaloid found in Huperzia serrata and used in various neurological conditions, including Alzheimer’s disease (AD). This study elucidated the binding of HpzA with HSA using advanced computational approaches such as molecular docking and molecular dynamic (MD) simulation followed by fluorescence-based binding assays. The molecular docking result showed plausible interaction between HpzA and HSA. The MD simulation and principal component analysis (PCA) results supported the stable interactions of the protein–ligand complex. The fluorescence assay further validated the in silico study, revealing significant binding affinity between HpzA and HSA. This study advocated that HpzA acts as a latent HSA binding partner, which may be investigated further in AD therapy in experimental settings.

Protective effect of huperzine A on phenytoin induced cognition impairment: Behavioral and biochemical study

Phenytoin, a drug of choice for Epilepsy is also known for its adverse effects. The most common adverse effect due to phenytoin is cognition impairment. Cognition impairment is a serious problem in society as it debars the person's social life. Thus to overcome such a problem demand for a solution arises. Huperzine, sesquiterpene alkaloids having immense neuroprotective properties. Thus in this study, it was aimed to evaluate the effectiveness of huperzine on Phenytoin- induced Cognition Impairment. The protective effect of huperzine on phenytoin-induced cognition impairment was evaluated in rats. The effect of Huperzine on phenytoin-induced cognitive impairment was evaluated by behavioral, biochemical, and histopathological studies. The co-administration of huperzine with phenytoin showed significant results. The treatment of Huperzine with phenytoin resulted in significant improvement in learning and memory. The oxidative stress induced by Phenytoin was reversed by huperzine. A significant decrease in cholinesterase activity was also observed. The histopathology showed damaged neuronal cells in periventricular regions and cortex due to phenytoin which was altered by Huperzine. Thus, the present study demonstrates the protective effect of huperzine on phenytoin-induced cognition impairment.

Comparative Transcriptome Analysis of Genes Involved in Sesquiterpene Alkaloid Biosynthesis in Trichoderma longibrachiatum MD33 and UN32

Trichoderma longibrachiatum MD33, a sesquiterpene alkaloid-producing endophyte isolated from Dendrobium nobile, shows potential medical and industrial applications. To understand the molecular mechanisms of sesquiterpene alkaloids production, a comparative transcriptome analysis was performed on strain MD33 and its positive mutant UN32, which was created using Ultraviolet (UV) mutagenesis and nitrogen ion (N+) implantation. The alkaloid production of UN32 was 2.62 times more than that of MD33. One thousand twenty-four differentially expressed genes (DEGs), including 519 up-regulated and 505 down-regulated genes, were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed 139 GO terms and 87 biosynthesis pathways. Dendrobine, arguably the main sesquiterpene alkaloid the strain MD33 produced, might start synthesis through the mevalonate (MVA) pathway. Several MVA pathway enzyme-coding genes (hydroxy-methylglutaryl-CoA synthase, mevalonate kinase, and farnesyl diphosphate synthase) were found to be differentially expressed, suggesting that physical mutagenesis can disrupt genome integrity and gene expression. Some backbone post-modification enzymes and transcript factors were either discovered, suggesting the sesquiterpene alkaloid metabolism in T. longibrachiatum is a complex genetic network. Our findings help to shed light on the underlying molecular regulatory mechanism of sesquiterpene alkaloids production in T. longibrachiatum.

Effects of RNAi-mediated plasma membrane calcium transporting ATPase and inositol 1,4,5-trisphosphate receptor gene silencing on the susceptibility of Mythimna separata to wilforine

Wilforine, a compound of sesquiterpene alkaloids isolated from Tripterygium wilfordii, exhibits excellent insecticidal activity against Mythimna separata. In order to clarify the action mechanism of wilforine, the plasma membrane calcium transporting ATPase (PMCA) and inositol 1,4,5-trisphosphate receptor (IP3R) from M. separata were studied. Results showed that the open reading frame of MsIP3R and MsPMCA were 8118 bp and 3438 bp in length, as well as encoded 2706 and 1146 amino acids, respectively. Multiple sequence alignment and phylogenetic analysis revealed that the MsIP3R and MsPMCA had high homology with the IP3R and PMCA of other insects, but had low similarity with those of mammals, which means the IP3R and PMCA have potential to be the novel targets of insecticides with high selectivity between mammals and insects. Both MsIP3R and MsPMCA genes existed throughout the life cycle of M. separata, and were all predominantly expressed in somatic muscle of fifth-instar larvae and the adults. The susceptibilities of PMCA-silenced M. separata to wilforine were significantly lower than that of the normal M. separata, which illustrates that PMCA could be one of the targets of wilforine. However, the susceptibilities of IP3R-silenced M. separata to wilforine did not change significantly compared with the susceptibilities of normal M. separata, which shows that wilforine may not interact with the IP3R protein. These findings provide clues for elucidating the insecticidal mechanism of wilforine.

Metabolic characterization of a potent natural neuroprotective agent dendrobine in vitro and in rats.

Dendrobine is the main sesquiterpene alkaloid of Dendrobium nobile Lindl, which exhibits potent neuroprotective activity. However, its metabolism and disposition are little known. In this study, we investigated the metabolic characteristics of dendrobine in vitro and in rats. The metabolic stability and temporal profile of metabolites formation of dendrobine were assayed in human/rat liver microsomal and S9 fractions. Dendrobine metabolites were separated and identified mainly by UPLC-Q/Orbitrap MS. After oral administration of dendrobine (50 mg/kg) to rats, the accumulative excretion rate of dendrobine in feces, urine, and bile was 0.27%, 0.52%, and 0.031%, respectively, and low systematic exposure of dendrobine (AUC0-∞ = 629.2 ± 56.4 ng·h/mL) was observed. We demonstrated that the elimination of dendrobine was very rapid in liver microsomal incubation (the in vitro elimination t1/2 in rat and human liver microsomes was 1.35 and 5.61 min, respectively). Dendrobine underwent rapid and extensive metabolism; cytochrome P450, especially CYP3A4, CYP2B6, and CYP2C19, were mainly responsible for its metabolism. Aldehyde dehydrogenase, alcohol dehydrogenase and aldehyde oxidase were involved in the formation of carboxylic acid metabolites. By the aid of in-source fragmentation screening, hydrogen/deuterium exchange experiment, post-acquisition processing software, and available reference standards, 50 metabolites were identified and characterized in liver microsomal incubation and in rats. The major metabolic pathways of dendrobine were N-demethylation, N-oxidation, and dehydrogenation, followed by hydroxylation and glucuronidation. Collectively, the metabolic fate of dendrobine elucidated in this study not only yields benefits for its subsequent metabolism study but also facilitates to better understanding the mode of action of dendrobine and evaluating the pharmacologic efficiency of the high exposure metabolites.

Consoramides A–C, New Zwitterionic Alkaloids from the Fungus Irpex consors

In our ongoing search for new secondary metabolites from fungi, a basidiomycete fungus Irpex consors was selected for mycochemical investigation, and three new zwitterionic alkaloids (1-3) and five known compounds (4-8) were isolated from the culture broth (16 l) of I. consors. The culture filtrate was fractionated by a series of column chromatography including Diaion HP-20, silica gel, and Sephadex LH-20, Sep-Pak C18 cartridge, medium pressure liquid chromatography (MPLC), and high pressure liquid chromatography (HPLC) to yield eight compounds (1-8). The structures of the isolated compounds were elucidated by the interpretation of nuclear magnetic resonance (NMR) spectra and high-resolution mass spectrometry (HR-MS). Their antioxidant and antibacterial activities were examined. The zwitterionic structures of three new sesquiterpene alkaloids (1-3) were determined together with five known compounds identified as stereumamide E (4), stereumamide G (5), stereumamide H (6), stereumamide D (7), and sterostrein H (8). This is the first report of the zwitterionic alkaloids in the culture broth of I. consors. Three new zwitterionic alkaloids were named as consoramides A–C (1-3).

Synthesis of ent-Plagiochianin B

Key words (–)-ent-plagiochianin B - sesquiterpene alkaloids - Mukaiyama aldol reaction - reductive carbonylation - 6π electrocyclization - aromatization - Wacker oxidation - Sharpless dihydroxylation

Greenwaylactams A, B and C, the First Group of Sesquiterpene Alkaloids with an Eight‐Membered Lactam Ring from Greenwayodendron oliveri

AbstractThree new sesquiterpene alkaloids of the polyveoline type containing eight‐membered lactam rings named greenwaylactam A (1), B (2) and C (3) were isolated from the leaves of a Cameroonian medicinal plant Greenwayodendron oliveri (Engl.) Verdc along with three known compounds diacetylpolyveoline (4), N‐acetyl‐8α‐polyveolinone (5) and methyl pheophorbide‐A (6). These comprise the first members of a new class of ξ‐lactam sesquiterpenes. Compounds were isolated by means of successive column chromatographies and their structures were elucidated by extensive NMR spectroscopic analyses and HRESIMS. The configuration of 1 was deduced from its single‐crystal X‐ray diffraction. The crude extract and some isolated compounds were assessed for their antibacterial activity against four enteric bacterial strains Escherichia coli, Salmonelles typhi, Shigella dysenterie and Klebseilla pneumonie using the micro‐dilution method. Compounds 1, 2, 5 and 6 were the most active with MIC values varying between 31.25–250 μg/mL.

Identification of phenolic constituents inLonicera caeruleaL. by HPLC with diode array detection electrospray ionisation tandem mass spectrometry

The purpose of this work was a comparative metabolomic study of extracts of Blueberried honeysuckleLonicera caeruleaL.: №1043-11 (St. Petersburg); №1043-08 (St. Petersburg) №863; (Japan); №860 (WildLonicerafrom Amur river) from the collection of N.I. Vavilov All-Russian Institute of Plant Genetic Resources. To identify target analytes in extracts HPLC was used in combination with a BRUKER DALTONIKS ion trap. The results showed the presence of 82 target analytes corresponding to familyCaprifoliaceae. In addition to the reported metabolites, a number of metabolites were newly annotated inLonicera caeruleaL.There were flavonols: Dihydrokaempferol, Rhamnetin I, Rhamnetin II, Taxifolin-3O-glucoside, Mearnsetin-hexoside, Horridin; flavones: Chrysoeriol, Apigenin-O-pentoside, Chrysoeriol-7-Oglucoside; flavanone Naringenin; flavan-3-ols: Catechin, Epicatechin, Biochanin A-7-O-glucoside; essential amino acids: L-Pyroglutamic acid, Tyrosine; polypeptide 5-Oxo-L-propyl-L-isoleucine; sterols: Ergosterol, Fucosterol, Beta-Sitosterin; triterpenoids: Betunolic acid, Oleanoic acid; anabolic steroid Vebonol, indole sesquiterpene alkaloid Sespendole; iridoids: Monotropein,p-Coumaroyl monotropein,p-Coumaroyl monotropein hexoside; Myristoleic acid, etc.