Essential Oil from Vietnamese Peperomia leptostachya Hook. & Arn. (Piperaceae): Chemical Composition, Antioxidant, Anti-Inflammatory, Cytotoxic Activities, and In Silico Analysis.

This study is the first to investigate the chemical composition and antioxidant, anti-inflammatory, and cytotoxic activities of Peperomia leptostachya leaf oil. A yellow oil was obtained through hydro-distillation, with a yield of 0.1% (w/w). The GC-MS analysis revealed 66 compounds, constituting 99.6% of the oil. Sesquiterpene hydrocarbons predominated (70.4%), followed by monoterpene hydrocarbons (13.2%), oxygenated sesquiterpenes (12.4%), non-terpenic compounds (2.0%), and oxygenated monoterpenes (1.6%). Major constituents included germacrene D (25.1%), (E)-caryophyllene (17.4%), bicyclogermacrene (6.6%), α-pinene (6.2%), and ß-pinene (4.7%). The assessment of antioxidant capacity via 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay yielded a weak effect, with an IC50 value > 100 µg/mL. The inhibition of lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells was quantified using the MTT assay, showing an IC50 value of 15.15 ± 0.68 µg/mL. Furthermore, cytotoxic effects on SK-LU-1 cell line growth were evaluated using the sulforhodamine B assay, resulting in an IC50 value of 37.45 ± 2.43 µg/mL. The anti-inflammatory activity was notable among the analyzed bioactivities of this oil. By employing a computational model, the predominant secondary metabolites in the essential oil were selected as candidates for interaction analysis with cyclooxygenase-2, an enzyme implicated in the inflammatory response. Our findings suggest that P. leptostachya leaf oil could serve as a potential source of natural compounds with prospective therapeutic effects in treating inflammatory conditions.

Conamonin A and dihydrochalcones from the whole plants of Conamomum rubidum (Lamxay & N.S.Lý) Skornick. & A.D. Poulsen showing anti-inflammatory and cytotoxic activities.

A new compound, conamonin A (1), was isolated from the whole plants of Conamomum rubidum with eight known dihydrochalcones (2-9). Their structures were elucidated by a combination of spectroscopic methods as well as by comparison with previously reported data. The absolute configuration of 1 was assigned by TDDFT-ECD method. Compounds 1 and 8 showed inhibitory activity against LPS-induced NO production in the RAW 264.7 cells, with IC50 values of 58.29 ± 2.88 and 81.77 ± 5.99 µM, respectively. Compounds 3/4 and 5/6 exhibited inhibitory effects, with IC50 values of 28.76 ± 1.16 and 29.89 ± 1.79 µg/mL, respectively. Compounds 2, 7-9 exhibited significant cytotoxic activity against human lung carcinoma (the SK-LU-1 cell line) with IC50 values ranging from 9.87 to 17.99 µM. This study offers valuable insights into the chemical constituents and biological activities of Conamomum rubidum, highlighting its potential as a source for discovering new anti-inflammatory and cytotoxic agents.

Chemical composition and biological activities of essential oil from Grewia bulot leaves.

This study focused on the chemical composition and biological activities of the essential oil derived from Grewia bulot, a plant species known for its medicinal properties. The analysis of Grewia bulot essential oil revealed the presence of 78 constituents. The major compounds were α-cadinol (13.5%), 1,8-cineole (12.7%), 1,10-di-epi-cubenol (9.8%), epi-α-cadinol (6.7%), (E,E)-α-farnesene (5.9%), (E)-citral (4.0%), selin-11-en-4-α-ol (4.0%), citronellol isobutanoate (3.9%), and geranic acid (3.7%). The essential oil exhibited promising antioxidant potential with an IC50 value of 452.65 ± 28.40 µg/mL in DPPH model. This oil did not show NO production inhibitory effect in RAW 264.7 cells. In addition, the essential oil exhibited significant cytotoxicity against KB, Hep-G2, MCF-7, and SK-LU-1 cancer cell lines, with IC50 values ranging from 44.04 ± 1.47 to 74.20 ± 3.71 µg/mL.

Facile access to 5H-thiazolo[2',3':2,3]imidazo[4,5-b]indole derivatives by two-fold Cu-catalysed C-N coupling reactions.

In four simple steps, a series of 5H-thiazolo[2',3':2,3]imidazo[4,5-b]indole and 11H-benzo[4',5']thiazolo[2',3':2,3]imidazo[4,5-b]indole derivatives were prepared with high yields. The key step in this procedure was demonstrated to be two-fold Cu-catalysed C-N coupling reactions of 5-bromo-6-(2-bromophenyl)imidazo[2,1-b]thiazole and 3-bromo-2-(2-bromophenyl)benzo[d]imidazo[2,1-b]thiazole with various amines.

Chemical constituents from the Knema globularia fruits and their in vitro cytotoxicity.

Two new compounds, designated as knecorticosanones A-B (1-2), along with three known compounds (3-5) were isolated from the fruits of Knema globularia. Their structures were elucidated by extensive spectroscopy analysis, including 1D- and 2D-NMR, UV, IR, and HRESIMS and by comparison with the reported data in the literature. Compounds 1-5 were evaluated for their cytotoxicity. Knecorticosanone B (2) and malabaricone D (5) exhibited moderate cytotoxic effect against Hep-G2, MCF-7 and SK-LU-1 cell lines with IC50 values ranging from 8.76 ± 1.02 to 18.74 ± 1.75 µM while knecorticosanone A (1), virolane (3) and 7-hydroxy-3',4'-methylenedioxyflavan (4) exhibited weak inhibitory effect against these cell lines with IC50 values ranging from 25.85 ± 2.75 to 66.75 ± 2.08 µM.