Structurally diverse limonoids and bio-active evaluation from Trichilia connaroides.

Four new limonoids, named as trichiconlide G (1), 2-hydroxyltrijugin F (2), 23-oxo-21-hydroxyltrijugin F (3), 21-oxo-23-hydroxyltrijugin F (4), along with sixteen known analogues (5-20) were isolated from the leaves and twigs of Trichilia connaroides. Their structures and absolute configurations were determined by spectroscopic analyses, X-ray diffraction analysis, and TD-DFT-ECD calculations. Trichiconlide G (1) is one rare naturally occurring 1,2-seco phragmalin-type limonoid bearing a C-7/28 δ-lactone ring. Additionally, 2-hydroxyltrijugin F (2), 23-oxo-21-hydroxyltrijugin F (3), and 21-oxo-23-hydroxyltrijugin F (4) are three naturally occurring limonoids with a rare C-16/8 δ-lactone ring. All isolates were evaluated for their cytotoxic and anti-inflammatory activities. None of compounds exhibited cytotoxicity against five human cancer cell lines A-549, HepG2, 5-8F, Siha, and SCC-4 at the concentration of 40 µM. Compounds 16 and 17 showed moderate anti-inflammatory activity with IC50 values of 28.45 ± 2.51 and 22.66 ± 2.01 µM, respectively.

Four new steroids from the leaves and twigs of Dysoxylum pallens and their cytotoxic activities.

Four previously undescribed steroids, identified as (3S,7S,8S,9S,10R,13S,14S,16S,17R,20S)-7α-methoxy-ergosta-5,24(28)-dien-3ß,16ß,20-triol (1), ergosta-5,24(28)-dien-3ß,7α,16ß-triol (2), ergosta-5,25-dien-3ß,7α,16ß,20-tetrol (3) and 7α,16ß,24α-trihydroxy-varninasterol (4), as well as five known analogues (5-9), were isolated from the leaves and twigs of Dysoxylum pallens Hiern (Meliaceae). Their structures were elucidated based on extensive spectroscopic analysis such as HR-ESI-MS, 1D and 2D NMR, UV, and IR. The absolute configuration of compound 1 was determined by X-ray diffraction analysis. Selected compounds were evaluated for their cytotoxic activities. Compounds 1, 2, and 8 exhibited moderate cytotoxic activity against HL-60, Hela, and HepG2 tumor cell lines with IC50 ranged from 11.09 to 17.51 µM.

Aspidoptoids A-D: Four New Diterpenoids from Aspidopterys obcordata Vine.

Four new diterpenoids, named aspidoptoids A-D (1-4), together with two known analogues (5-6) were isolated from Aspidopterys obcordata vine. Aspidoptoids A-B (1-2) are the first examples of phenylethylene-bearing 20-nor-diterpenoids of which aspidoptoid B (2) possesses a rare 3,10-oxybridge. Their structures and absolute configuration were determined by extensive spectroscopic analyses (IR, HRESIMS, 1D and 2D NMR) and electronic circular dichroism (ECD) calculation. In addition, all the isolates were evaluated for their cytotoxic activities and inhibitory effects on the nitric oxide (NO) production.