Complete 1 H and 13 C assignments of two new sesquiterpenoids from Dendrobium aduncum.

Two new sesquiterpenoids, dendroaduoid A (1) and dendroaduol (2), together with four known sesquiterpenoids were isolated from the stems of Dendrobium aduncum. Their structures were identified by HR-ESI-MS and NMR experiments, and the complete assignments of 1 H and 13 C NMR data for two new sesquiterpenoids were obtained by the aid of HSQC, HMBC, 1 H-1 H COSY, NOESY, and ECD techniques. The cytotoxic effects of the isolated compounds on four tumor cell lines (HCT-116, HepG2, A549, and SW1990) were evaluated using MTT assay. Otherwise, the inhibitory activity of these six sesquiterpenoids on glycosidase was also evaluated.

Structural elucidation of lactone derivatives from Dendrobium pendulum.

Six lactone derivatives, including four α-pyrones derivatives (1-4), two α-furanone derivatives (5 and 6), were isolated from the Dendrobium pendulum. Structural elucidation of these undescribed lactone derivatives were accomplished on the basis of detailed nuclear magnetic resonance analysis, and the absolute configurations of compounds 1-4 were confirmed by electronic circular dichroism (ECD) techniques. The cytotoxic effects of isolated compounds on human breast cancer cell MDA-MB-231 were evaluated by the MTT assay.

Secondary Metabolites from Dendrobium nobile and Their Activities Induce Metabolites Apoptosis in OSC-19 Cells.

To identify potential drug candidates, secondary metabolites of Dendrobium nobile were performed. As a result, two previously undescribed phenanthrene derivatives with a spirolactone ring (1 and 2), along with four known compounds, N-trans-cinnamoyltyramine (3), N-trans-p-coumaroyltyramine (4), N-trans-feruloyltyramine (5), and moscatilin (6), were isolated from Dendrobium nobile. The structures of the undescribed compounds were elucidated using NMR spectroscopy, electronic circular dichroism (ECD) calculations, and extensive spectroscopic data analysis. The cytotoxic effects of compounds on human tongue squamous cells OSC-19 were determined using MTT at concentrations of 2.5 µM, 5 µM, 10 µM, and 20 µM. Compound 6 exhibited potent inhibitory activity against OSC-19 cells with an IC50 of 1.32 µM. Migration assays and western blot assays demonstrated that compound 6 effectively inhibited migration by down-regulating MMP2 and MMP9 at concentrations of 0.5 µM and 1 µM. To investigate its effect on apoptosis, we performed AO/PI staining, flow cytometry, and WB experiments. The results showed that increasing concentrations led to increased red fluorescence, decreased green fluorescence, increased apoptosis rate, decreased expression of bcl-2, caspase 3, caspase 9, and parp proteins, and increased bax expression. Furthermore, the phosphorylation of JNK and P38 was activated, suggesting that compound 6 may induce apoptosis via the MAPK pathway.

A new triterpenoids from Nothotsuga longibracteata.

A new lanostane triterpenoid (1) and two known (2, 3) analogues were isolated from Nothotsuga longibracteata. Their chemical structures were identified by spectral data including HR-ESI-MS, 1 D, and 2 D NMR. These lanostane triterpenoids showed no cytotoxic activities against three human tumour cell lines (A172, SHSY5Y, and Hela), but exhibited the activity of promoting the gastrointestinal motility of zebrafish treated with Nile red.

Chemical constituents of Bletilla striata.

A new triphenanthrene compound named 2,2',2'',7,7',7''-hexahydroxy-4,4',4''-trimethoxy-[9,9',9'',10,10',10'']-hexahydro-1,8,1',6''-triphenanthrene (1), together with eleven known compounds (2－12), were isolated from tubers of Bletilla striata. Their structures were determined by analysis of spectroscopic data.

Mahimbrine A, a Novel Isoquinoline Alkaloid Bearing a Benzotropolone Moiety from Mahonia imbricata.

A novel isoquinoline alkaloid, mahimbrine A, possessing a rare benzotropolone framing scaffold, was isolated from the endemic plant of Mahonia imbricata. Its structure was established on the basis of extensive spectroscopic analysis. A plausible biosynthetic route of mahimbrine A was proposed. Mahimbrine A showed no antimicrobial activity at the concentration of 1 mg/mL.

Polycyclic Spiro Lignans and Biphenyl Tetrahydrofuranone Lignans from Gymnotheca involucrata.

Four rare polycyclic spiro lignans (1-4) and four new biphenyl tetrahydrofuranone lignans (5-8) were isolated from the whole plant of Gymnotheca involucrata. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis and the absolute configuration of 1 was confirmed by single crystal X-ray diffraction. Bioassay results showed that compounds 2 and 6 exhibited weak antifungal activity against Uromyces viciae-fabae at 100 ppm in leaf-disc assays, while compound 3 demonstrated moderate insecticidal activity against Diabrotica balteata at 500 ppm in an artificial diet assay.

Three new oxazoline alkaloids from Gymnotheca chinensis.

Three novel oxazoline alkaloids, 1-oxa-3-azaspiro [4.5] dec-2-ene-8-one (1), 1-oxa-3-azaspiro [4.5] dec-2, 6-diene-8-one (2), and 1-oxa-3-azaspiro [4.5] dec-10-methoxy-2, 6-diene-8-one (3) were isolated from the methanol extract of the whole plant of Gymnotheca chinensis. The chemical structures were established by means of spectroscopic analysis including one- and two-dimensional NMR spectroscopy.

[A new bibenzyl compound from Dendrobium nobile].

In this study, seven bibenzyl compounds were isolated from the stem of Dendrobium nobile by silica gel, MCI column chromatographic and preparative HPLC technology. By using spectroscopic techniques including NMR and MS, these compounds were identified as 4,α-dihydroxy-3,5,3'-trimethoxybibenzyl (1), 4,5-dihydroxy-3,3',α-trimethoxybibenzyl (2), 4,4'-dihydroxy-3,5,3'-trimethoxybibenzyl (3), 4,5-dihydroxy-3,3'-dimethoxybibenzyl(4), 4,3'-dihydroxy-3,5-dimethoxybibenzyl (5), 5,4'-dihydroxy-3,3'-dimethoxybibenzyl (6) and 5,3'-dihydroxy-3-methoxybibenzyl (7). Compound 1 is a new compound and compound 4 was isolated from this plant for the first time.

Strategy to rapidly discriminate trace isomeric lignan compounds from Gymnotheca chinensis by probe electrospray ionization tandem mass spectrometry.

Probe electrospray ionization (PESI) is a recently developed ionization technique based on electrospray ionization (ESI) that generates electrospray from the tip of a solid needle. High tolerance to salts, requirements of a trace amount of sample and direct ambient sampling- are major advantages of PESI compared with conventional ESI. In this report, three pairs of isomeric lignans bearing tetra-hydrofuran with variable conformations from Gymnotheca chinensis were investigated by probe electrospray tandem mass spectrometry (PESI-MS/MS) in the positive ion mode. The diagnostic characteristics of these compounds were obtained and the isomers could be successfully distinguished by comparison with their breakdown curves, even though the isomers differed only in the conformation of some groups of the isomer pairs. This report provides a rapid and reliable method for the identification of trace amounts of isomeric lignans by PESI-MS/MS. Furthermore, application of PESI and breakdown curves should have value in mass spectrometry studies of isomeric natural products compounds.

Diterpenoids from Torreya grandis and their cytotoxic activities.

Eight previously undescribed diterpenoids, along with eleven previously reported analogues, were obtained from the supercritical CO2 extracts of Torreya grandis aril. The structures of these compounds were elucidated based on HRESIMS, NMR, ECD, and single-crystal X-ray diffraction data. In the MTT assay, compound 18 exhibited significant inhibitory effects on two human colon cancer cell lines, HT-29 and HCT 116 cells, with IC50 values of 7.37 µM and 6.55 µM, respectively. It was found that compound 18 induced apoptosis and significantly inhibited the migration of HCT 116 colon cancer cells in a concentration-dependent manner.

Isoprenoid flavonoids isolated from Sophora davidii and their activities induces apoptosis and autophagy in HT29 cells.

Four previously undescribed isoprenoid flavonoids (2-5) were isolated from Sophora davidii, along with five known analogues. The structures of the compounds were established through comprehensive analysis of spectroscopic data, including HRESIMS, 1D and 2D NMR, and absolute configurations determined by theoretical calculations, including ECD and NMR calculation. The cytotoxic effects of the isolated compounds on human HT29 colon cancer cells were evaluated using the MTT assay, compound 1 exhibited cytotoxicity against human HT29 colon cancer cells with an IC50 value of 8.39 ± 0.09 µM. Studies conducted with compound 1 in HT29 cells demonstrated that it may induce apoptosis and autophagy in HT29 by promoting the phosphorylation of P38 MAPK and inhibiting the phosphorylation of Erk MAPK.

[Triterpenes from aerial parts of Clematoclethra scandens subsp. actinidioides].

To study the chemical constituents of Clematoclethra scandens subsp. actinidioides, chromatographic methods such as silica gel and MCI column chromatographic technology, and preparative HPLC were used and sixteen compounds were isolated from the aerial parts of this plant. By using spectroscopic techniques including 1H, 13C-NMR, HMBC and ESI-MS, these compounds were identified as betulinic acid (1), ursolic acid (2), oleanic acid (3), corosolic acid (4), 3beta-(trans-p-coumaroyloxy)-2alpha, 23-dihydroxyurs-12-en-28-oic acid (5), 3beta-(trans-p-coumaroyloxy)-2alpha, 23-dihydroxyurs-12, 20 (30)-dien-28-oic acid (6), 2alpha, 3alpha, 23-trihydroxyurs-12, 20 (30)-dien-28-oic acid (7), 2alpha, 3alpha, 23-trihydroxyurs-12-en-28-oic acid (8), asiatic acid (9), 2alpha, 3alpha, 24-tri-hydroxyurs-12-en-28-oic acid (10), 2alpha, 3beta, 23-trihydroxyurs-12, 20 (30)-dien-28-oic acid (11), 2alpha, 3beta, 19alpha, 24-tetrahydroxyurs-12-en-28-oic acid (12), 2alpha, 3alpha, 19alpha, 24-tetrahydroxyurs-12-en-28-oic acid (13), 2alpha, 3beta, 23, 24-tetrahydroxyurs-12-en-28-oic acid (14), 2alpha, 3alpha, 19alpha, 23, 24-pentahydroxyurs-12-en-28-oic acid (15) and daucosterol (16). Among them, compounds 3-6, 11-12, 14 and 15 were isolated from this endemic plant for the first time.

FOXA2 attenuates lipopolysaccharide­induced pneumonia by inhibiting the inflammatory response, oxidative stress and apoptosis through blocking of p38/STAT3 signaling.

Pneumonia is a severe inflammatory disease of the lung. Forkhead box protein A2 (FOXA2) has been demonstrated to serve an important regulatory role in various pulmonary diseases; however, the role of FOXA2 in pneumonia remains to be elucidated. The present study aimed to explore the functional effects and regulatory mechanism of FOXA2 in pneumonia. An in vitro pneumonia model was induced using lipopolysaccharide (LPS) in WI-38 cells. The mRNA and protein expression levels of FOXA2 were determined by reverse transcription-quantitative PCR and western blotting, respectively. Cell viability was assessed using a Cell Counting Kit-8 assay. Inflammatory cytokines were evaluated using ELISA kits and oxidative stress markers were assessed using a malondialdehyde assay kit, superoxide dismutase assay kit and CATalase assay kit. Cell apoptosis was evaluated using flow cytometry and the caspase3 activity was determined. Western blotting was performed to examine the protein expression levels of endoplasmic reticulum stress (ERS)-associated factors. For a rescue assay, a p38 MAPK activator, U46619, was used to investigate the regulatory mechanism of FOXA2 involving p38/STAT3 signaling. FOXA2 was downregulated in LPS-induced WI-38 cells. FOXA2 overexpression alleviated LPS-induced inflammation, oxidative stress, apoptosis and ERS in WI-38 cells. Furthermore, the inhibitory effects of FOXA2 on inflammation, oxidative stress and apoptosis, as well as ERS in LPS-induced WI-38 cells were partly weakened by additional treatment with U46619. In conclusion, FOXA2 served a protective role against LPS-induced pneumonia by regulating p38/STAT3 signaling, providing a novel idea for the development of targeted therapeutic strategies for pneumonia.

Organophotoredox-Catalyzed Intermolecular Formal Grob Fragmentation of Cyclic Alcohols with Activated Allylic Acetates.

We have developed an efficient method that employs organophotoredox-catalyzed relay Grob fragmentation to facilitate the smooth ring-opening allylation of cyclic alcohols in an environmentally friendly manner. This protocol directly incorporates a wide spectrum of cyclic alcohols and activated allylic acetates into the cross-coupling reaction, eliminating the need for metal catalysts. The process yields a variety of distally unsaturated ketones with good to excellent outcomes and stereoselectivity, while acetic acid is the sole byproduct.

Dihydrophenanthrenes and phenanthrenes from Dendrobium terminale.

Two previously undescribed dihydrophenanthrene derivatives (1 and 2) were isolated along with twelve known analogues from the whole plant of Dendrobium terminale. The structures of the new compounds were elucidated on the basis of detailed spectroscopic analysis. The NMR data of known phenanthrene derivatives (7 and 9) were revised by 2D NMR. The isolated compounds were evaluated for cytotoxicity against three kinds of tumor cell lines (sw1990, HCT-116, and HepG2). Especially compounds 11 and 14 showed stronger antitumor effects, and the structure-activity relationship of these compounds was discussed.

Fluoroalkylation of Activated Allylic Acetates through Radical-Radical Coupling: Organophotoredox/DABCO Catalytic System.

A novel organophotoredox/DABCO catalytic system for the fluoroalkylation of activated allylic acetates via radical-radical coupling is described. The method offers mild reaction conditions, high selectivity, and broad substrate compatibility and enabled diverse bioactive molecules, FDA-approved drugs, and amino acid derivatives to be incorporated into transformation. This study expands the synthetic toolbox for the construction of fluorine-containing molecules.

Total biflavonoids extraction from Selaginella chaetoloma utilizing ultrasound-assisted deep eutectic solvent: Optimization of conditions, extraction mechanism, and biological activity in vitro.

In this study, the deep eutectic solvent based ultrasound-assisted extraction (DES-UAE) was investigated for the efficient and environmentally friendly extraction of Selaginella chaetoloma total biflavonoids (SCTB). As an extractant for optimization, tetrapropylaminium bromide-1,4-butanediol (Tpr-But) was employed for the first time. 36 DESs were created, with Tpr-But producing the most effective results. Based on response surface methodology (RSM), the greatest extraction rate of SCTB was determined to be 21.68 ± 0.78 mg/g, the molar ratio of HBD to HBA was 3.70:1, the extraction temperature was 57 °C, and the water content of DES was 22 %. In accordance with Fick's second rule, a kinetic model for the extraction of SCTB by DES-UAE has been derived. With correlation coefficients 0.91, the kinetic model of the extraction process was significantly correlated with the general and exponential equations of kinetics, and some important kinetic parameters such as rate constants, energy of activation and raffinate rate were determined. In addition, molecular dynamics simulations were used to study the extraction mechanisms generated by different solvents. Comparing the effect of several extraction methods on S.chaetoloma using ultrasound-assisted extraction and conventional methods, together with SEM examination, revealed that DES-UAE not only saved time but also enhanced SCTB extraction rate by 1.5-3 folds. SCTB demonstrated superior antioxidant activity in three studies in vitro. Furthermore, the extract could suppress the growth of A549, HCT-116, HepG2, and HT-29 cancer cells. Alpha-Glucosidase (AG) inhibition experiment and molecular docking studies suggested that SCTB exhibited strong inhibitory activity against AG and potential hypoglycemic effects. The results of this study indicated that a Tpr-But-based UAE method was suitable for the efficient and environmentally friendly extraction of SCTB, and also shed light on the mechanisms responsible for the increased extraction efficiency, which could aid in the application of S.chaetoloma and provide insight into the extraction mechanism of DES.

Dendrobine-type alkaloids from Dendrobium nobile.

Six dendrobine-type alkaloids were isolated from the tubes of Dendrobium nobile by silica gel, Sephadex LH-20 gel column chromatography, and preparative HPLC. Compound 1 is a new alkaloid containing a pair of amide tautomers, whereas compound 2 is a new dendrobine-type alkaloid. By using spectroscopic techniques including 1 D and 2 D NMR, the structures of compounds 1‒6 were identified as N-methoxylcarbonyldendrobine (1), dendronboic acid (2), dendrobine (3), 6-hydroxyldendrobine (4), dendrobine N-oxide (5), and denrine (6). The cytotoxic effects of the isolated compounds on two human tumour cell lines (HCT-116 and SW1990) were evaluated using MTT assay.

Genome-Wide Identification of Genes Related to Biosynthesis of Phenolic Acid Derivatives in Bletilla striata at Different Suspension Culture Stages.

To screen the genes regulating the biosynthesis of phenolic acid derivatives from the genome of Bletilla striata, we designed a suspension culture system to sample the cells for the following experiments. The contents of four phenolic acid derivatives were determined by high-performance liquid chromatography, and several full-length transcriptome sequencings of RNA samples at 10 time points were performed for bioinformatics analysis. The correlation analysis was used to identify and verify the key DEGs involved in the biosynthesis of the four phenolic acid derivatives. The results showed that the contents of p-hydroxybenzylalcohol (HBA), Dactylorhin A, Militarine, and Coelonin peaked at 33 days postinoculation (Dpi), 18 Dpi, 39 Dpi, and 39 Dpi of the culture system, respectively. Based on transcriptome data, 80 DEGs involved in the biosynthesis of phenolic acid derivatives were obtained. The KEGG pathway enrichment analysis classified them mostly into five metabolic pathways: phenylpropane biosynthesis, starch and sucrose metabolic, cyanoamino acid metabolism, gluconeogenesis and glycolysis, and phenylalanine metabolism. qPCR analysis revealed that the relative gene expression levels were consistent with the overall trend of transcriptome sequencing results. Among them, 14, 18, 23, and 41 unigenes were found to be involved in the synthesis of HBA, Dactylorhin A, Coelonin, and Militarine, respectively. These unigenes laid a solid foundation for elucidating the biosynthesis mechanism of phenolic acid derivatives in suspension cells of B. striata.