Chuan Yang, Shaoqiong Liu, Nikken Wiradharma, Jeremy Tan, Zhan Yuin Ong, Yan Li, Xin Ding, Siti Nurhanna Riduan, Yugen Zhang and Yiyan Yang

Due to the increasing resistance of bacteria to conventional antibiotics, macromolecular antimicrobial peptides and polymers have received significant attention. Most conventional antibiotics do not physically damage the cell wall but penetrate into the target microorganism and act on specific targets, such as breakage of double-stranded DNA due to inhibition of DNA gyrase, blockage of cell division and triggering of the intrinsic autolysins. As a consequence, bacterial morphology is preserved and the bacteria can easily develop resistance. In contrast, our macromolecular antimicrobials do not have a specific target in microbes, and they interact with microbial membranes based on electrostatic interaction, thereby inducing damage to the microbial membranes by forming pores in the membranes. This physical action prevents microbes from developing resistance. In this project, we have designed and synthesized antimicrobial peptides and polymers so that they can self-assemble into nanostructures in aqueous solution to enhance antimicrobial efficacy. The structure of the macromolecules will be optimized in terms of hydrophobicity/hydrophilicity balance, molecular weight, counter ion and quaternization agent to achieve strong antimicrobial activities with no or minimal toxicity for applications in blood stream or skin infections, tuberculosis, surface sterilization and consumer products.

Yugen Zhang, Michael Reithofer, Liuqun Gu, Dingyi Yu, Siti Nurhanna Riduan, Mei Xuan Tan, and Jackie Y. Ying

Green chemistry is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. To achieve this target, we are interested in the development of novel green and environmentally friendly technology for organic synthesis and the pharmaceuticals industry. Our research is focused on metal-free organo catalysis, sustainable resources (e.g. using CO₂ as C1 resource), and environmentally benign catalysis (e.g. non-toxic, inexpensive iron catalysts and water-mediated reactions). We are also interested in the development of alternative and renewable energy resources and technologies through the use of novel catalyst systems. This includes creating highly efficient and highly selective catalyst systems for the dehydration of biomass into chemicals, fuels and materials. We are also working on transforming greenhouse gases such as carbon dioxide into useful chemicals or fuels such as methanol.

Yugen Zhang, Ting Lu, Liuqun Gu, Siti Nurhanna Riduan, Leng Leng Chng, Nandanan Erathodiyil and Jackie Y. Ying

Heterogeneous catalysis has many advantages over homogeneous catalysis. However, there are certain limitations on current protocols for producing heterogeneous catalysts via the immobilization of homogeneous catalysts onto inorganic or organic solid supports. This project aims to develop a new type of supported catalysts based on mesoporous silica and polymers, and organic-inorganic nanocomposites. This research will focus on the development of new materials and new chemistry. Organocatalysts, organometallic catalysts or biocatalysts will be investigated. The aim of this study is to build new catalyst support platforms to develop highly efficient catalyst systems. The target heterogeneous catalysts will allow for the synthesis of pharmaceuticals with superb activity, excellent enantioselectivity and recyclability. They will also enhance efficiency in the production of pharmaceuticals and specialty chemicals.

Guangshun Yi, Liuqun Gu, Ting Lu, Yin Ngai Sum and Yugen Zhang

The diminishing fossil fuel reserves and the effects of global warming are of major concerns. Hence, the development of sustainable biomass-derived energy and chemicals to replace the dependence on petroleum feedstock is of critical importance. This project aims to develop highly efficient catalyst systems, green and cost-efficient processes for the production of industrial chemicals from raw biomass and biomass-derived feedstock, such as cellulose, sugars, glycerol and bioethanol. Our targets include useful chemicals such as 5-hydroxymethylfurfural (HMF), 2,5-furandicarboxylic acid (FDCA), acrylic acid, adipic acid, olefins, xylitol, and sorbitol.