一價銠金屬催化肉桂胺衍生物進行不對稱氫芳基化反應
Rhodium(I)-Catalyzed Asymmetric Hydroarylation of Cinnamylamine Derivatives
一價銠金屬催化反應已經被廣泛應用於有機化學合成領域中。而本研究以具保護基之肉桂胺衍生物1與四芳基硼鈉試劑2a作為起始物進行銠金屬不對稱氫芳基化催化反應,得到具有保護基的掌性2,3-雙芳基丙胺衍生物3,並探討此反應的掌性雙烯配基對於反應的影響。本研究已完成使用Ts(對甲苯磺醯基)保護基之肉桂胺衍生物1a作為起始物進行反應,並改變與銠金屬錯合的配基,發現當配基使用2,5號位為芳基取代之配基L(掌性雙環[2,2,1]雙烯配基)時,反應有較好的位置選擇性,其中最佳的是芳基取代為苯基之配基L1,其位置選擇性比例為1:0:0.09。目前將進行改變起始物1之氮上的保護基,以L1作為配基進行反應,並與1a比較,優化反應性及產率。
Trojan Horses in the Fight against Skin Cancer
In photodynamic therapy (PDT), reactive oxygen species are generated within the cytoplasm to destroy cancer cells selectively. Using porphyrinic structures (PS) as photosensitizers holds promise for targeting cancer cells. However, direct incorporation of the porphyrins into cancer cells remains elusive. Hence, Dr. Martina Vermathen’s research introduced specific membranous phospholipid nanocarriers for topical porphyrin applications. However, since a sufficiently high enough concentration of PS in cancer cells has not yet been achieved, this study aimed to improve skin uptake of the nanocarriers. Two approaches were examined: (1) comparing polar and nonpolar porphyrins and (2) assessing the effect of a penetration enhancer, DMSO, through a neat and diluted application. The polarity of the porphyrins was first quantified with a log P test. The nanocarriers were assembled by incorporating two different PS compounds, either the mono- or tetra-4-carboxy substituted phenyl porphyrin. They were then characterized by 1D and 2D-NMR analysis. The porphyrin permeation was tested by Franz diffusion tests on pig ear skin. For the second approach, DMSO was added in the Franz diffusion test, either directly applied on the skin (“neat“) or diluted in the nanocarriers (“diluted”). The log P test for the mono- and the tetra-carboxyphenyl porphyrin resulted in values of 4.5 and -1.1, respectively. The more polar tetra-carboxyphenyl porphyrin exhibited 2.8 times better skin uptake compared to the mono-carboxyphenyl porphyrin. The neat DMSO application increased uptake by a factor of 5.5. The diluted DMSO application worsened skin uptake slightly. Analytical techniques revealed differences in porphyrin encapsulation: The mono-carboxyphenyl porphyrins were encapsulated in the centre, whereas tetra-carboxyphenyl porphyrins were localised around the nanocarriers. Results indicated potential instability of the nanocarriers. The more polar tetra-substituted porphyrins showed superior skin diffusion than the mono-substituted derivative. The neat DMSO application facilitated enhanced skin uptake by inducing membrane destabilization and pore formation but may have limited applicability. Further research is suggested to explore porphyrinic PS with alternative polar substitution patterns and tailored penetration enhancers for lipid-based delivery systems. Overall, the study underscores the importance of molecular properties of the PS system and demonstrates the potential of penetration enhancers in optimizing PDT for skin cancer treatment.
Development of Oil Collecting Submarine using AI and hydrophobic solution
Such as the plastic waste and industrial discharge that permeate our oceans, it is the insidious and infamous nature of oil spills that demands our immediate attention. These spills, with their far-reaching ecological ramifications, pose a profound danger to our marine ecosystems, demanding urgent action and a heightened awareness of the true menace that is caused by this oil