ABSTRACT
Two new ent-labdane diterpenoids, hypoestesins A-B (1-2) and five new labdane diterpenoids, hypopurolides H-L (3-7), were isolated from the aerial parts of Hypoestes purpurea. All of the structures were fully determined based on extensive analysis of 1H, 13C, 2D NMR, and HRESIMS data. The absolute configurations of 1-3 was established through comparing the experimental and calculated ECD curves and the structure of 5 was confirmed by single crystal X-ray diffraction experiment. Compounds 5-7 were unusual C23 labdane diterpenoids having a γ-acetonyl-α, ß-unsaturated γ-lactone unit and each assigned as C-15 epimeric mixture. Furthermore, cytotoxic and anti-inflammatory activities of 3-7 were evaluated. The results showed that 3 had remarkable cytotoxic activity against HL-60, A549, SMMC-7721, MDA-MB-231, and SW480 cancer cell lines with IC50 values ranging from 2.35 to 17.06 µM. Compound 4 showed moderate cytotoxic activity against HL-60 and SMMC-7721 cancer cell lines with IC50 values of 15.12 ± 0.53 and 12.92 ± 0.60 µM, respectively. Furthermore, compound 4 was also found to exhibit inhibitory activity against NO production in RAW 264.7 macrophages with IC50 values of 23.56 ± 0.99 µM, compared to the positive control L-NMMA with an IC50 value of 41.11 ± 1.34 µM.
ABSTRACT
Eight previously undescribed diterpenoids, caesamins A-H (1-8), were separated and identified from the seeds of Caesalpinia minax Hance. Their structures were characterized by extensive spectroscopic data and X-ray crystallographic analysis. Structurally, caesamin A (1) is the first cassane-type diterpenoid with a C23 carbon skeleton containing an unusual isopropyl. Caesamin F (6) represents the first example of cleistanthane diterpenoid from the genus Caesalpinia. Caesamins B (2) and F (6) exhibited inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages with IC50 values of 45.67 ± 0.92 and 42.99 ± 0.24 µM, comparable to positive control 43.69 ± 2.62 µM of NG-Monomethyl-L-arginine. Furthermore, the chemotaxonomic significance of the isolates was discussed.
ABSTRACT
Here, we used reverse transcription-PCR (RT-PCR) and western blot to detect protease-activated receptor (PAR) 1, PAR 2 and PAR 4 expression in cancer tissues and cell lines of esophageal squamous cell carcinoma, and investigated the co-relationship between PAR expression and clinic-pathological data for esophageal cancer. The methylation of PAR4 gene promoter involved in esophageal carcinoma was also analyzed. By comparing the mRNA expressions of normal esophageal tissue and human esophageal epithelial cells (HEEpiC), we found that among the 28 cases of esophageal squamous cell carcinoma, PAR1 (60%) and PAR2 (71%) were elevated in 17 and 20 cases, respectively, and PAR4 (68%) expression was lowered in 19 cases. Whereas, in human esophageal squamous cells (TE-1 and TE-10), PAR1 and PAR2 expression was increased but PAR4 was decreased. Combined with clinical data, the expression of PAR1 in poorly differentiated (P=0.016) and middle and lower parts of the esophagus (P=0.016) was higher; expression of PAR4 in poorly differentiated carcinoma was lower (P=0.049). Regarding TE-1 and TE-10 protein expression, we found that in randomized esophageal carcinoma, PAR1 (P=0.027) and PAR2 (P=0.039) expressions were increased, but lowered for PAR4 (P=0.0001). In HEEpiC, TE-1, TE-10, esophageal and normal esophagus tissue samples (case No. 7), the frequency of methylation at the 19 CpG loci of PAR4 was 35.4%, 95.2%, 83.8%, 62.6% and 48.2%, respectively. Our results indicate that the expression of PAR1 and PAR2 in esophageal squamous cell carcinoma is increased but PAR4 is decreased. Hypermethylation of the promoter of the PAR4 gene may contribute to reduced expression of PAR4 in esophageal squamous cell carcinoma.
