Herein, we discussed the arsenal of short peptides and peptidomimetics starting from the smallest unit possible - a dipeptide to a decapeptide along with their activity profiles as antimicrobials. Recently, various SAMPs have paved their ways from in vitro studies to clinical trials, as evident from the most recent patent (EP1951194) on oral hygiene. This step by step growth of SAMPs has restored the hope in peptide-based therapeutics, which may prove an essential tool in eradicating antimicrobial resistance and tackling various microbial infections.

The growing incidents of cryptococcosis in immuno-compromised patients have created a need for novel drug therapies capable of eradicating the disease. The peptide-based drug therapy offers many advantages over the traditional therapeutic agents, which has been exploited in the present study by synthesizing a series of hexapeptides that exhibits promising activity against a panel of Gram-negative and Gram-positive bacteria and various pathogenic fungal strains; the most exemplary activity was observed against Cryptococcus neoformans. The peptides 3, 24, 32 and 36 displayed potent anticryptococcal activity (IC50 = 0.4 – 0.46 μg/mL, MIC = 0.63 – 1.25 μg/mL, MFC = 0.63 – 1.25 μg/mL), and stability under proteolytic conditions. Besides this, several other peptides displayed promising inhibition of pathogenic bacteria. The prominent ones include peptides 18–20, and 26 that exhibited IC50 values ranged between 2.1 – 3.6 μg/mL, MICs of 5 – 20 μg/mL and MBCs of 10 – 20 μg/mL against Staphylococcus aureus and methicillin-resistant S. aureus. The detailed mechanistic study on selected peptides demonstrated absolute selectivity towards the bacterial membranes and fungal cells by causing perturbations in the cell membranes, confirmed by the scanning electron microscopy and transmission electron microscopy studies.

A series of peptides derived from the C-terminus fragment (Aβ38–42) of Aβ showed significant to complete reduction in Aβ-induced toxicity.

Heterocyclic compounds are that type of substances that are deeply intertwined with biological processes. Heterocycles are found in about 90% of commercially available medicines. In medicinal chemistry, finding new synthetic molecules with drug-like characteristics is a regular problem, which triggered the development of pharmacological molecules, the majority of which are based on N-heterocyclic motifs. Among the heterocycles, the pyrrole scaffold is the most commonly found heterocycle in both natural and synthetic bioactive compounds. Pyrrole has a five-membered heterocyclic ring with a plethora of pharmacophores, resulting in a library of different lead compounds. Pyrrole derivatives are physiologically active heterocyclic compounds that can be used as scaffolds for antibacterial, antiviral, anticancer, antitubercular, anti-inflammatory, and as enzyme inhibitors. On account of its extensive pharmacological profile, pyrrole and its various synthetic derivatives have drawn much attention among researchers to explore it for the benefit of humankind. This review presents an overview of recent developments in the pyrrole derivatives against multiple therapeutic targets.