A new cassane diterpenoid from the seed of Caesalpinia sappan.

In this study, a previously undescribed cassane diterpenoid, named caesalpinin JF (1), along with two known cassane diterpenoids caesanine C (2) and tomocinol B (3), was isolated from 95% EtOH extract of the seeds of Caesalpinia sappan Linn. Additionally, three known compounds including pulcherrin R (4), syringaresinol-4'-O-ß-D-glucopyranoside (5) and kaempferol (6) were also identified. The structures of the isolated compounds were elucidated by comprehensive 1D and 2D NMR spectroscopic analyses. Additionally, electronic circular dichroism (ECD) calculation was used to identify the absolute structure of compound 1. Among the isolated compounds, compound 1 displayed a potent anti-neuroinflammation with an IC50 value of 9.87 ± 1.71 µM.

Influences of operating parameters on liquefaction performances of Tetra Pak in sub-/supercritical water.

Liquefaction performances of waste Tetra Pak in sub-/supercritical water were evaluated in micro-batch reactors. The influences of temperature (300-420 °C), pressure (16-24 MPa), residence time (5-60 min) and feed concentration (5-40 wt%) on bio-oil yield, high heating value (HHV), and functional groups in bio-oil were investigated. The results showed that bio-oil yield firstly increased with increasing temperature and then decreased when the temperature exceeded 360 °C. Reaction time longer than 30 min gave a negative effect on bio-oil yield. The influence of pressure on bio-oil yield increased markedly from 16 MPa to 22 MPa, and then stabilized. The feed concentration higher than 20 wt% showed little influence on bio-oil yield. Maximum bio-oil yield of 35.55% was found at 360 °C, 22 MPa, 30 min and feed concentration of 20 wt%. HHV and energy recovery efficiency increased significantly with temperature, and maximum HHV of 48.747 MJ/kg and energy recovery efficiency of 46.49% were found at 420 °C, 20 MPa, 30 min and feed concentration of 20 wt%. The main compounds in bio-oil and morphology of the solid residue were also analyzed, and the possible liquefaction pathways of Tetra Pak were proposed.

Supercritical water oxidation of quinazoline: Reaction kinetics and modeling.

This paper presents a first quantitative kinetic model for supercritical water oxidation (SCWO) of quinazoline that describes the formation and interconversion of intermediates and final products at 673-873 K. The set of 11 reaction pathways for phenol, pyrimidine, naphthalene, NH3, etc, involved in the simplified reaction network proved sufficient for fitting the experimental results satisfactorily. We validated the model prediction ability on CO2 yields at initial quinazoline loading not used in the parameter estimation. Reaction rate analysis and sensitivity analysis indicate that nearly all reactions reach their thermodynamic equilibrium within 300 s. The pyrimidine yielding from quinazoline is the dominant ring-opening pathway and provides a significant contribution to CO2 formation. Low sensitivity of NH3 decomposition rate to concentration confirms its refractory nature in SCWO. Nitrogen content in liquid products decreases whereas that in gaseous phase increases as reaction time prolonged. The nitrogen predicted by the model in gaseous phase combined with the experimental nitrogen in liquid products gives an accurate nitrogen balance of conversion process.

Supercritical water oxidation of Quinazoline: Effects of conversion parameters and reaction mechanism.

The supercritical water oxidation reaction of quinazoline and a set of related reaction products were investigated in batch reactors by varying the temperature (T, 400-600 °C), time (t, 0-400 s), water density (ρ, 70.79-166.28  kg m(-3)) and oxidation coefficient (OC, 0-4.0). The TOC removal efficiency (CRE) increased significantly as the OC increased, whereas this effect was very limited at high OC (>2.0). Lack of oxygen resulted in low CRE and TN removal efficiency (NRE), also cause coke-formation, and giving high yield of NH3 and nitrogenous organic intermediates. Prolonging reaction time did not provide an appreciable improvement on CRE but remarkably increased NRE at temperature higher than 500 °C. Pyrimidines and pyridines as the nitrogenous intermediates were largely found in GC-MS spectrum. Polymerization among benzene, phenyl radical and benzyl radical played important roles in the formation of PAHs, such as naphthalene, biphenyl, phenanthrene. These collective results showed how the yield of intermediate products responded to changes in the process variables, which permitted the development of a potential reaction network for supercritical water oxidation of quinazoline.