Ethyl Pyruvate

A novel, highly efficient condensation approach for the preparation of heterogeneous vanadium silicate microspherical catalyst is introduced.This synthetic method is based on a microwave-assisted preparation of hybrid vanadium biphenyl dicarboxylate-based precursor solution and subsequent condensation with (3-aminopropyl)triethoxysilane.The as-prepared hybrid metallosilicate is then calcined at 500°C to obtain amorphous and porous vanadium silicate microspheres with highly dispersed vanadium species inserted into the silicate matrix.This catalyst with 2.85 weight% of vanadium contains evenly distributed VO_x species, which possesses high catalytic activity in a cyclohexene epoxidation reaction, reaching a conversion of 54% after 4 h with 92% selectivity to cyclohexene oxide.The catalyst's TOF value achieved 220 h^-1, indicating its high performance compared to vanadium-containing catalyst analogs.Furthermore, a significant catalytic activity of prepared vanadium silicate microspheres in Et lactate oxidation to Et pyruvate with the conversion of 21% at mild conditions shows a high potential of the catalyst for industrial application compared to the contemporary V₂O₅ heterogeneous catalyst.

Camellia oleifera oil (CO) is renowned in China for its exceptional nutritional benefits and distinctive aroma. The aroma of old CO from oil-tea tree ages over 30 years differs markedly from that of young CO aged below 8 years. However, the volatile organic compounds (VOCs) and aroma characteristics of CO from oil-tea tree at different ages remain unclear. This study identified 82 VOCs using GC-IMS and 112 VOCs using GC-MS. PCA, PLS-DA, correlation analysis, and VIP values revealed distinct VOC profiles between CO obtained from young and old oil-tea tree. The principal characteristic VOCs of CO from young oil-tea tree (4 and 8 years) were 3-methyl-3-buten-1-ol (sweet fruit) and 3-methylbutyl propanoate (apple, apricot, and pineapple). Moreover, the predominant characteristic VOCs of CO from old oil-tea tree (30, 40, and 50 years) were 4-methyl-2-pentanol (pungent), butyl acetate (apple and banana), limonene (lemon and orange), and 2-ethyl-6-methylpyrazine (green, nuts, and roasted).