Lindenane sesquiterpenoid dimers from Chloranthus holostegius with anti-neuroinflammatory activities in BV-2 microglia.

Fifteen undescribed lindenane-type sesquiterpenoid dimers, designated chloranholides F-T (1-15), together with twenty-five known analogs (16-40), were isolated from the whole plants of Chloranthus holostegius. The isolate structures were elucidated by analysis of spectroscopic data and chemical methods, and their absolute configurations were determined by X-ray crystallography and electronic circular dichroism spectra. In anti-neuroinflammatory assays, all isolates were evaluated by examination of their inhibitory effect on nitric oxide (NO) in LPS-stimulated BV-2 cells, and the results showed that 21-24, 26, 30, 32 and 36 significantly inhibited the production of the inflammatory mediator NO, with IC50 values ranging from 3.18 to 11.46 µM, which was better than that of quercetin. Structure-activity relationship analysis revealed that two essential functional groups played an indispensable role in the anti-inflammatory effects. Moreover, 22 and 24 inhibited the LPS-induced upregulation of iNOS and COX-2 enzymes in BV-2 microglia at the protein level.

Undescribed phloroglucinol derivatives with antiviral activities from Dryopteris atrata (Wall. Ex Kunze) Ching.

Nine undescribed phloroglucinol derivatives (dryatraols A-I) with five different backbones and three known dimeric acylphloroglucinols were isolated from the rhizome of Dryopteris atrata (Wall. Ex Kunze) Ching (Dryopteridaceae). Dryatraol A contains an unprecedented carbon skeleton-a butyrylphloroglucinol and a rulepidanol-type sesquiterpene are linked via a furan ring to form a 6/5/6/6 ring system. Dryatraols B and C are the first examples of monomeric phloroglucinols coupled with the aristolane-type sesquiterpene through the C-C bond. Dryatraol D features a rare spiro [benzofuran-2',5″-furan] backbone. Dryatraols E-I are five undescribed adducts with a butyrylphloroglucinol or filicinic acid incorporated into the germacrene-type sesquiterpene via a pyran ring. These undescribed structures were determined by comprehensively analysing the spectroscopic data, X-ray diffraction results, and electronic circular dichroism calculations. The result of in vitro antiviral activity evaluation indicated that dryatraol C displayed the strongest antiviral effect against both respiratory syncytial virus and influenza A virus (H1N1), with IC50 values of 11.9 µM and 5.5 µM, respectively. Dryatraols F-H exhibited considerable inhibitory activity against herpes simplex virus type 1 (HSV-1), with IC50 values ranging from 2.6 to 6.3 µM. Analysis of the inhibitory mechanism using a time-of-addition assay revealed that dryatraol G may inhibit the replication of HSV-1 by interfering with the late stage of the viral life cycle.

Three new compounds isolated from the whole plants of Salsola collina pall.

One new alkaloid, 6, 7-dimethoxyisoquinoline-N-oxide (1), one new benzofuran derivative, 3,7-dimethyl-6-acetyl-8-benzofuranol (2) and one new lignan, salsolains A (3), along with seven known compounds (4-10), were isolated from the whole plant of Salsola collina Pall. Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HR-ESI-MS, 1 D and 2 D NMR), and their absolute configurations were determined by the X-ray crystallography and ECD calculation. The activities of compounds 1-10 against inflammatory cytokines IL-6 and TNF-α levels on LPS-induced RAW 264.7 macrophages were assessed, especially, compound 5 (50 µM) exhibited the most significant anti-inflammatory activity with the secretion levels of IL-6 and TNF-α at 3.87% and 4.03%, respectively.

Water-soluble matrine-type alkaloids with potential anti-neuroinflammatory activities from the seeds of Sophora alopecuroides.

A phytochemical investigation on the alkaloids from water-soluble part of Sophora alopecuroides led to obtain forty matrine-type alkaloids (1-40) including eighteen new ones (1-18), which covers almost all positions of the oxygen substitution in matrine-type structure. Notably, eight compounds (1-8) belong to rare bis-amide matrine-type alkaloid. The new structures were determined based on extensive spectroscopic data, electronic circular dichroism (ECD) calculations, and six instances, verified by X-ray crystallography. Most of isolates showed anti-neuroinflammatory activities based on the expression of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in BV2 microglia cells. Especially, compound 39 can suppress those two mediator secretions in a dose-dependent manner with IC50 values of 21.6 ± 0.5 and 16.7 ± 0.8 µM, respectively. Further mechanistic study revealed that 39 suppressed the phosphorylation of IκBα and p65 subunit to regulate the NF-κB signaling pathway.

Two new isoquinoline alkaloids from the seeds of Nandina domestica.

Two new isoquinoline alkaloids, 6 R,6aS-N-nantenine Nß-oxide (1), 6S,6aS-N-nantenine Nα-oxide (2), along with nine known alkaloids, nantenine (3), oxonantenine (4), protopine (5), nornantenine (6), N-methyl-laurotetanine (7), isocorydine (8), O-methyflavinantine (9), N-methyl-2,3,6-trimethoxymorphinan-dien-7-one Nß-oxide (10) and (+)-10-O-methylhernovine Nß-oxide (11) were isolated from the seeds of Nandina domestica. Their structures were elucidated by extensive analyses of spectroscopic data (IR, UV, HRESIMS, 1 D and 2 D NMR), ECD calculation and comparison with the related literatures. In addition, the cytotoxicity against A549 cells of these alkaloids was determined by the MTT assay.

One new sesquiterpene pyridine alkaloid from the stems and leaves of Euonymus fortunei.

A new sesquiterpene pyridine alkaloid (1), along with four known compounds (2-5), were isolated from the stems and leaves of Euonymus fortunei. The new structure was determined by extensive spectroscopic analyses (IR, UV, NMR, HRESIMS and ECD). In addition, compound 3 showed a stronger anti-respiratory syncytial virus (RSV) activity with an IC50 value of 1.20 ± 0.10 µM than the positive control ribavirin with an IC50 value of 5.62 ± 0.49 µM.[Formula: see text].

ß-Carboline Alkaloids from the Seeds of Peganum harmala and Their Anti-HSV-2 Virus Activities.

Pegaharines A-G (1-6), six novel ß-carboline alkaloids representing three types of skeleton, were isolated from the seeds of Peganum harmala. Compound 1 is a peculiar ß-carboline alkaloid characterized by the unprecedented carbon skeleton of an azepine-indole system. Compounds 3-6 represent the first examples of heterodimers constructed from rare tetracyclic ß-carboline and classic tricyclic ß-carboline alkaloids. Compounds 1 and 2 were characterized by X-ray crystallography. Compound 4 exhibited strong antiviral activity against HSV-2, with an IC50 value of 2.12 ± 0.14 µM.

Inhibitory Effect of PIK-24 on Respiratory Syncytial Virus Entry by Blocking Phosphatidylinositol-3 Kinase Signaling.

Phosphoinositide-3 kinase signaling modulates many cellular processes, including cell survival, proliferation, differentiation, and apoptosis. Currently, it is known that the establishment of respiratory syncytial virus infection requires phosphoinositide-3 kinase signaling. However, the regulatory pattern of phosphoinositide-3 kinase signaling or its corresponding molecular mechanism during respiratory syncytial virus entry remains unclear. Here, the involvement of phosphoinositide-3 kinase signaling in respiratory syncytial virus entry was studied. PIK-24, a novel compound designed with phosphoinositide-3 kinase as a target, had potent anti-respiratory syncytial virus activity both in vitro and in vivo PIK-24 significantly reduced viral entry into the host cell through blocking the late stage of the fusion process. In a mouse model, PIK-24 effectively reduced the viral load and alleviated inflammation in lung tissue. Subsequent studies on the antiviral mechanism of PIK-24 revealed that viral entry was accompanied by phosphoinositide-3 kinase signaling activation, downstream RhoA and cofilin upregulation, and actin cytoskeleton rearrangement. PIK-24 treatment significantly reversed all these effects. The disruption of actin cytoskeleton dynamics or the modulation of phosphoinositide-3 kinase activity by knockdown also affected viral entry efficacy. Altogether, it is reasonable to conclude that the antiviral activity of PIK-24 depends on the phosphoinositide-3 kinase signaling and that the use of phosphoinositide-3 kinase signaling to regulate actin cytoskeleton rearrangement plays a key role in respiratory syncytial virus entry.

Isolation and identification of new prenylated acetophenone derivatives from Acronychia oligophlebia.

Three new prenylated acetophenone derivatives, acronyculatin P (1), acronyculatin Q (2), and acronyculatin R (3) were isolated from the leaves of Acronychia oligophlebia. Their structures were identified by extensive analyses of spectroscopic data (IR, UV, ESI-HRMS, 1D and 2D NMR) and comparison with the literatures. In addition, the cytotoxic activity against MCF-7 cells of the compounds were evaluated by the MTT assay and the IC50 values were 56.8, 40.4 and 69.1 µM, respectively.

Sophalines E-I, Five Quinolizidine-Based Alkaloids with Antiviral Activities against the Hepatitis B Virus from the Seeds of Sophora alopecuroides.

Five novel quinolizidine-based alkaloids (1-5) were obtained from the seeds of Sophora alopecuroides L. Compounds 1 and 2 are the first examples of sparteine-indolizine and matrine-indolizine alkaloids, respectively, whereas 3 and 4 are epimeric normatrine-julolidine alkaloids with unusual skeletons. The structures of these compounds were determined by spectroscopic methods, single-crystal X-ray diffraction, and electronic circular dichroism analyses. Hypothetical biosynthetic pathways of 1-5 were proposed. Compound 2 exhibited significant antiviral activity against the hepatitis B virus.

Cytotoxic and anti-inflammatory active phloroglucinol derivatives from Rhodomyrtus tomentosa.

Seven undescribed phloroglucinol derivatives, tomentodiones N-T, and eleven known ones were isolated from Rhodomyrtus tomentosa. Tomentodione N is the first example of a ß-triketone unit coupled with an isoamyl alcohol through a furan fused-ring, and tomentodiones N, S, T were three racemates. The undescribed structures were elucidated by means of spectroscopic, X-ray diffraction, electronic circular dichroism calculation, and chemical methods. In addition, the isolated compounds were determined for the cytotoxic activities on HeLa cells and anti-inflammatory activities in LPS-stimulated RAW 264.7 cells.

New Acetophenone Derivatives from Acronychia oligophlebia and Their Anti-inflammatory and Antioxidant Activities.

Seven new acetophenone derivatives (acroliones A - G, 1 - 7) and three known ones (8 - 10) were isolated from the leaves of Acronychia oligophlebia. Their structures were elucidated based on extensive spectroscopic analyses (IR, UV, HR-ESI-MS, 1D- and 2D-NMR), X-ray diffraction and comparison with literature data. The anti-inflammatory and antioxidant activities of all isolates were evaluated.

Six New Acylphloroglucinols from Dryopteris championii.

Six new acylphloroglucinols (1 - 6) were isolated from Dryopteris championii. Their structures were established on the basis of extensive analysis of spectroscopic data and comparison with reported data. The antibacterial activities of the isolates were evaluated against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Dickeya zeae.

Sesquiterpene lactones from Elephantopus mollis and their anti-inflammatory activities.

Seven sesquiterpene lactones, 8-O-methacryloylelephanpane, 2,4-bis-O-methyl-8-O-methacryloylelephanpane, 4-O-ethyl-8-O-methacryloylelephanpane, 8-O-methacryloylisoelephanpane, 2-O-demethyltomenphantopin C, molephantin A, molephantin B, along with ten known ones, were isolated from Elephantopus mollis (Asteraceae). Their structures were elucidated by extensive analysis of spectroscopic data (IR, UV, HRESIMS, 1D and 2D NMR). The isolates were evaluated for their anti-inflammatory activities on LPS-stimulated RAW 264.7 cells, and all tested compounds exhibited potent anti-inflammatory effects with IC50 values of 0.57 ± 0.17 to 14.34 ± 1.61 µM, except that compound tomenphantopin C exhibited moderate anti-inflammatory activity with IC50 values of 59.97 ± 1.53 µM.

Four Matrine-Based Alkaloids with Antiviral Activities against HBV from the Seeds of Sophora alopecuroides.

Four novel matrine-based alkaloids (1-4) were isolated from the seeds of Sophora alopecuroides. Compounds 1 and 2 possess unprecedented 6/6/6/4 and 6/5/6/6 ring systems, respectively, while 3 and 4 are a pair of stereoisomeric matrine-acetophenone alkaloids with an unusual skeleton. Their structures were elucidated by means of spectroscopic methods and single-crystal X-ray diffraction. Hypothetical biogenetic pathways for 1-4 are proposed, and their antiviral activities are also discussed.

Diterpenoid Alkaloids from Delphinium ajacis and Their Anti-RSV Activities.

Five new diterpenoid alkaloids, ajacisines A-E (1-5), were isolated from Delphinium ajacis, along with seven known alkaloids (6-12). On the basis of their spectral data (IR, UV, HR-ESI-MS, 1D and 2D NMR) and chemical properties, the structures of compounds 1-12 were identified. All isolated compounds were evaluated for their in vitro antiviral activities against respiratory syncytial virus, and compounds 3-5 and 8 exhibited moderate to weak effects with IC50 values of 75.2 ± 1.1, 35.1 ± 0.6, 10.1 ± 0.3, and 50.2 ± 0.5 µM, respectively.

Three new diterpenoids from Croton laui Merr. et Metc.

Three new diterpenoids, including one labdane diterpenoid (1) and two cembrane diterpenoids (2-3), were isolated from the aerial parts of Croton laui, along with four known analogues (4-7). Their structures were elucidated by spectroscopic analysis and comparison with literature data. All compounds were evaluated for their cytotoxicity against two tumour cell lines.

Six New Pentacyclic Triterpenoids from the Fruit of Camptotheca acuminata.

Six new pentacyclic triterpenoids were isolated from the fruit of Camptotheca acuminata. The chemical structures of the new compounds were elucidated by extensive spectroscopic analysis including HR-ESI-MS, IR, UV, 1D- and 2D-NMR. Moreover, the antibacterial activities of compounds 1, 2, 4, 5, and 6 were evaluated against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Dickeya zeae. All these tested compounds showed moderate antibacterial activity against Bacillus subtilis and Dickeya zeae.

Drychampones A-C: Three Meroterpenoids from Dryopteris championii.

Three novel sesquiterpenoid-based meroterpenoids, drychampones A-C (1-3, respectively), were isolated from Dryopteris championii. Compounds 1 and 3 possessed a novel carbon skeleton which was constructed by an 11/6/6 ring system coupled with a pyronone moiety, and 1-3 were three racemates. Their structures and absolute configurations were elucidated by NMR, MS, and computational methods. The hypothetical biosynthetic pathways of these meroterpenoids and their antibacterial activities were also discussed.

New labdane diterpenoids from Croton laui and their anti-inflammatory activities.

Nine new labdane diterpenoids (1-9) were isolated from the aerial parts of Croton laui, along with eight known analogues (10-17). Their structures were identified on the basis of the spectral data (IR, UV, HRESIMS, 1D and 2D NMR), and the structure of 8 was confirmed by single crystal X-ray diffraction analyses. In addition, compounds 1, 4, 7, 8, and 14 showed weak anti-inflammatory activities in LPS-stimulated RAW 264.7 cells.