Zhong-Nan Wu

New Phloroglucinol Derivatives from the Fruit Tree Syzygium jambos and Their Cytotoxic and Antioxidant Activities

Seven new phloroglucinol derivatives (1-7) were isolated from the fruit tree Syzygium jambos together with four known triterpenoids (8-11) and two known flavones (12 and 13). According to the spectroscopic analyses (infrared, electrospray ionization mass spectrometry (ESIMS), high-resolution ESIMS, 1D and 2D nuclear magnetic resonance), the structures of compounds 1-7 were elucidated as jambone A (1), jambone B (2), jambone C (3), jambone D (4), jambone E (5), jambone F (6), and jambone G (7). All the isolates were determined for their cytotoxic activities on melanoma cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and compounds 10 and 11 showed potent activities. Moreover, compounds 1, 2, 4-7, 12, and 13 exhibited weak antioxidant activities under ferric-reducing antioxidant power and 2,2-diphenyl-1-picryhydrazyl radical-scavenging assays.

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.

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.

Six new prenylated acetophenone derivatives from the leaves of Acronychia oligophlebia.

Six new prenylated acetophenone derivatives were isolated from the leaves of Acronychia oligophlebia. The chemical structures of them were elucidated by extensive analysis of spectroscopic data (IR, UV, HRESIMS, 1D and 2D NMR). The cytotoxic activity of the isolates was evaluated against MCF-7 cells. Among these compounds, 2 and 6 exhibited mild cytotoxic activity with IC50 values of 33.5 and 25.6 μM, respectively.

Three new diterpenoids from Croton laui Merr. et Metc

Abstract 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.

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.

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 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.

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.