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Pegaharines A-G (1-6), six novel β-carboline alkaloids representing three types of skeleton, were isolated from the seeds of Peganum harmala. Compound 1 is a peculiar β-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 β-carboline and classic tricyclic β-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.

Two new isoquinoline alkaloids, 6 R,6aS-N-nantenine Nβ-oxide (1), 6S,6aS-N-nantenine Nα-oxide (2), along with nine known alkaloids, nantenine (3), oxonantenine (4), protopine (5), nornantenine (6),...

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.

Seven undescribed phloroglucinol derivatives, tomentodiones N−T, and eleven known ones were isolated from Rhodomyrtus tomentosa. Tomentodione N is the first example of a β-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.

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 new ent-kaurane diterpenes with chiral epoxyangelate moieties, (2′R,3′R)-3α-(2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (1), (2′S,3′S)-3α-(2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (2), (2′S,3′R)-3α-(2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (3) and (2′R,3′S)-3α-(2′,3′-epoxyangeloyloxy)-kaur-16-en-19-oic acid (4), along with eight known diterpenes (5−12), were isolated from Wedelia prostrata. The absolute configurations of the new structures were determined by X-ray crystallography, ECD calculations and chemical methods. All compounds were evaluated for their cytotoxicity activities on human HepG-2 cells, with IC50 values of 11.72 ± 0.22 μmol/L to 54.75 ± 1.12 μmol/L.

Two novel diterpenoid alkaloids, grandiflodines A and B (1 and 2), were isolated from Delphinium grandiflorum. Compound 1 represents a rare hetisine-type C20-diterpenoid alkaloid in which the bond between the atoms of N and C-17 is broken. Compound 2 features an unusual lycoctonine-type C19-diterpenoid alkaloid skeleton with the cleavage of N–C19 and C7–C17 bonds, and the construction of the N–C7 bond. Structural elucidations of the isolates were performed by spectroscopic analysis, X-ray diffraction and comparison with the literature. These compounds were tested for their antiviral and anti-inflammatory activities.

Phytochemical investigation of the ethanol extract from the rhizomes of Paris polyphylla var. yunnanensis led to the isolation of three steroid saponins (1–3) and two triterpenoid saponins (4, 5). Among them, compound 1 is a new steroid saponin, and 3–5 were obtained for the first time from the genus Paris. Their structures were elucidated on the basis of extensive analyses of spectroscopic data including IR, UV, MS, and 1D and 2D NMR. All of these compounds were tested for their cytotoxic activities on human nasopharyngeal cancer cells (CNE) and antiviral activities against respiratory syncytial virus (RSV). Steroidal saponins 1 and 2 showed moderate effects on CNE cells, with IC50 values 32.56 and 33.10 μM, respectively.

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.

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.

The rhizome of Dryopteris crassirhizoma Nakai is an important traditional Chinese medicine listed in Chinese Pharmacopoeia for the treatment of parasitic infestation and viral diseases. In this work, ten enantiomeric pairs of new acylphloroglucinol meroterpenoids, (±)-dryocrassoids A − J [(±)-1−10], along with six known acylphloroglucinols (11−16) were isolated from the rhizomes of D. crassirhizoma. Notably, these new enantiomers were the first examples of meroterpenoids constructed by acylphloroglucinols and nerolidol-type sesquiterpenes, while (±)-1a/1b, (±)-2a/2b, (±)-4a/4b were obtained as the inseparable interconverting mixtures of keto and enol tautomers. The new structures and absolute configurations were identified by the interpretation of high resolution electron spray ionization mass spectrum (HRESIMS), nuclear magnetic resonance (NMR) spectroscopic data, and quantum chemical electronic circular dichroism (ECD) calculations. In addition, these compounds were assayed for the in vitro antiviral activities against herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), and respiratory syncytial virus (RSV). The results indicated that most of the compounds showed anti-HSV-1 and anti-RSV effects to different extent under the concentration of 100 μM. This study provided evidences for further study and utilization of D. crassirhizoma in medicinal products.

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.

Three new diterpenoids, including one clerodane diterpenoid 1 and two linear diterpenoids 2 and 3, were isolated from the aerial parts of Croton laui, along with four known compounds 4–7. Structura...

Three new eudesmanolides, prostrolides A–C (1–3), along with six known compounds were isolated from the herbs of Wedelia prostrata (Asteraceae). The structures were determined by extensive analysis of their spectroscopic data (IR, UV, HRESIMS, 1D and 2D NMR). The isolated compounds were evaluated for their cytotoxic activity on human hepatocellular carcinoma HepG2 cells. All isolates exhibited cytotoxic activities with IC50 values of 4.60 ± 0.17 to 27.23 ± 0.36 µM.

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 (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. This article is protected by copyright. All rights reserved.

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.

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.

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.