Recent Development of Coumarin Derivatives as Potential Antiplasmodial and Antimalarial Agents.

Malaria still remains one of the leading deadliest diseases throughout the world, leading to around 1 million deaths annually. The emergence and spread of growing resistance to the firstline antimalarials are an alarming the serious problem in malaria control, demanding the need for new drugs more potent than earlier with improved Absorption, Distribution, Metabolism, and Excretion (ADME) profiles. Coumarins, which exhibited various biological properties, also displayed potential in vitro antiplasmodial and in vivo antimalarial activities. Moreover, many of coumarin derivatives have already been used in clinical practice for the treatment of several diseases. Therefore, coumarin derivatives play a pivotal role in medicinal chemistry, also making them promising candidates for the treatment of malaria. This review aims to summarize the recent advances made towards the development of coumarin-containing derivatives as antiplasmodial and antimalarial agents and their structure-activity relationship is also discussed.

Recent Developments of Coumarin Hybrids as Anti-fungal Agents.

Fungi place a huge burden on global healthcare systems attributed to the fact that fungal infections are responsible for the high morbidity and mortality rates in patients who received stem cell transplantation, antineoplastic chemotherapy, organ transplants or suffered Human Immunodeficiency Virus (HIV) infection. Unfortunately, almost none of the representative anti-fungal agents currently used in clinical therapy are ideal in terms of efficacy, anti-fungal spectrum or safety. Moreover, the rapid development of resistance to existing anti-fungal drugs has further aggravated the mortality and spread of fungi, creating an urgent need for novel anti-fungal agents. The broad spectrum of biological activities and successful usage in clinic made coumarins a promising anti-fungal candidate. Furthermore, hybridization of other pharmacophores with coumarin motif may enhance the anti-fungal efficacy, broaden the anti-fungal spectrum and improve the safety profiles. Thus, numerous coumarin hybrids have been assessed for their anti-fungal activities, and some of them showed promising potency and may have a novel mechanism of action. This review aims to outline the recent development of coumarin hybrids as potential anti-fungal agents and summarize their Structure-Activity Relationship (SAR) to provide an insight for rational designs of more active agents.

Antibacterial evaluation of novel organoarsenic compounds by the microcalorimetric method.

Antibacterial activities of novel organoarsenic compounds As(III)-containing Schiff bases on Escherichia coli (CCTCCAB91112) were investigated by microcalorimetry in this study. The experimental result showed that the arsenic(III)-containing Schiff bases at micromolar concentration exhibit strong inhibition on the E. coli. Specifically, the growth rate constant k decreased, and the generation time t G and the inhibitory ratio I (percentage) increased with the increased dose of the arsenicals as inhibitors. All of the arsenicals display the feature of considerable lag phase inhibition on the cell growth. The compound 4-(4-bromobenzaliminyl)phenylarsenoxide makes the lag phase of E. coli cell growth cycles to reach 650 min at 5 µmol/L. The compounds with donating electron groups at aromatic ring B have lower IC50 to present higher antibacterial activity. The compound 4-(4-hydroxyl-3-methoxylbenzaliminyl)phenylarsenoxide has the lowest IC50 (1.82 µmol/L) to show the strongest antibacterial activity among them.