Antimicrobial peptides (AMPs) are a class of peptides widely existing in nature with broad-spectrum antimicrobial activity. It is considered as a new alternative to traditional antibiotics because of its unique mechanism of antimicrobial activity. The development and application of natural AMPs are limited due to their drawbacks such as low antimicrobial activity and unstable metabolism. Therefore, the design and optimization of derived peptides based on natural antimicrobial peptides have become recent research hotspots. In this paper, we focus on ribosomal AMPs and summarize the design and optimization strategies of some related derived peptides, which include reasonable primary structure modification, cyclization strategy and computer-aided strategy. We expect to provide ideas for the design and optimization of antimicrobial peptides and the development of anti-infective drugs through analysis and summary in this paper.
Antimicrobial Cationic Peptides/chemistry* ; Antimicrobial Peptides ; Drug Design ; Anti-Infective Agents/pharmacology* ; Anti-Bacterial Agents

AIMTo study the effect of both light and heat on the stability of furacilin aqueous solution and the probability of substituting for isothermal accelerated tests by nonisothermal accelerated tests upon exposure to light at high temperatures.

METHODSThe isothermal and nonisothermal accelerated tests were employed. The accelerated tests were proceeded in the dark and exposed to light at high temperature. Tungsten, ultraviolet and fluorescent lamps were employed in exposure tests.

RESULTSThe degradation of furacilin aqueous solution in isothermal heating experiments or the exposure experiments to light at high temperatures obeys zero-order kinetics. The total degradation rate constant k caused by both light and heat can be divided into two parts: k = kdark + klight, where kdark and klight are the degradation rate constant caused by heat and light, respectively. The klight can be expressed as klight = Alight.exp(-Ea,light/RT).E, where E is the illuminance of light; Alight and Ea,light are both experimental constants. The parameters obtained in nonisothermal accelerated tests were comparable to those obtained in classic isothermal accelerated tests.

CONCLUSIONNonisothermal accelerated tests may substitute for isothermal accelerated tests during the study of the effects of both light and heat on the stability of drugs, in order to save time, labor and drugs.

PEGylating is an effective way for prolonging the half-time period and decreasing the immunogenicity of protein drugs. With experiments of single factor, it was proved that the optimal processes for PEGylating the fused protein of LL-37 and interferon (IFN)-α2a were: PEG molecular weight was 5,000, fused protein concentration was 0.6 mg/mL, the mole ratio of protein to mPEG₅₀₀₀-SS was 1:10, the reaction temperature was 4 °C, and the pH was 9.0, respectively. With orthogonal experiments, we proved that the influential order of 3 main factors is: the fused protein concentration > the mole ratio of protein and mPEG₅₀₀₀-SS > pH and the optimal conditions were the fused protein concentration as 0.6 mg/mL, the mole ratio of protein and mPEG₅₀₀₀-SS as 1:10, pH as 8.8. Under these optimal conditions, the average rate of PEGylated protein with 3 times parallel experiments was 86.98%. After PEGylated, the interferon activity and antimicrobial activity of fused protein could be remained higher than 58% and 97%, respectively.
Anti-Infective Agents ; chemistry ; Antimicrobial Cationic Peptides ; chemistry ; Interferon-alpha ; chemistry ; Polyethylene Glycols ; chemistry ; Recombinant Proteins ; chemistry

Andrographolide (AG) is a main effective ingredient in leaves of Andrographis paniculata. AG and its derivatives have such effects in anti-infection, anti-tumor and immuno-regulation. Particularly, its antibacterial, antiviral and anti-protozoal activities play an increasingly important role in resisting opportunistic infections. On the basis of our studies on AG over the years, we made a summary for the basis and clinical studies on AG and its derivatives over the past 10 years.
Andrographis ; chemistry ; Animals ; Anti-Infective Agents ; chemistry ; pharmacology ; Diterpenes ; chemistry ; pharmacology ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Humans ; Structure-Activity Relationship

Lawsonia inermis is a single-species genus of the Lythraceae family, its leaves, stem bark, roots, flowers and seeds have been used in traditional medicine. It has been paid more attention by scholars from many countries because of their various types of compounds and significant physiological activities. The plant is reported to contain quinones, phenylpropanoids, flavonoids, terpenoids, phenolic compounds and fatty acids. Modern pharmacological studies have demonstrated that the plant performs antimicrobial, antioxidant, anticancer and antiparasitic activity. This article mainly summarizes the research advances of chemical constituents and biological activities of Lawsonia inermis, for its further development and utilization.
Anti-Infective Agents ; chemistry ; pharmacology ; Antineoplastic Agents ; chemistry ; pharmacology ; Antioxidants ; chemistry ; pharmacology ; Antiparasitic Agents ; chemistry ; pharmacology ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Humans ; Lawsonia Plant ; chemistry

Mangroves are salt-tolerant forest ecosystem that extends between tropical and subtropical intertidal regions of the world. Mangroves are biochemically unique vegetation that produce wide array of natural products with immense medicinal potential. These plants are the most valuable resources and provide economic and ecological benefits to the coastal people. Natural products from these plants are of great interest as they provide innumerable direct and indirect benefits to human beings for the discovery of novel antimicrobial and other bioactive compounds. They possess active metabolites with some novel chemical structures that belong to diverse chemical classes such as alkaloids, phenol, steroids, terpenoids and tannins. Several mangrove species have been used in traditional medicine or have few applications as insecticide and pesticide. To date, several mangroves, and their associated species and solvent extracts are screened for antimicrobial activity along with the presence of potent bioactive compounds. The present article emphasizes and creates awareness about the potential mangrove plants and their associates as a source of biologically active compounds with potent antimicrobial properties. This paper also elaborates the mechanisms of action and various methods for screening of antimicrobial compounds.
Anti-Infective Agents ; isolation & purification ; pharmacology ; Avicennia ; chemistry ; Ecosystem ; Plant Extracts ; isolation & purification ; pharmacology

Marine microorganisms, especially marine fungi, have historically proven their value as a prolific source for structurally novel and pharmacologically active secondary metabolites (Deshmukh et al., 2018; Carroll et al., 2022). The corals constitute a dominant part of reefs with the highest biodiversity, and harbor highly diverse and abundant microbial symbionts in their tissue, skeleton, and mucus layer, with species-specific core members that are spatially partitioned across coral microhabitats (Wang WQ et al., 2022). The coral-associated fungi were very recently found to be vital producers of structurally diverse compounds, terpenes, alkaloids, peptides, aromatics, lactones, and steroids. They demonstrate a wide range of bioactivity such as anticancer, antimicrobial, and antifouling activity (Chen et al., 2022). The genetically powerful genus Emericella (Ascomycota), which has marine and terrestrial sources, includes over 30 species and is distributed worldwide. It is considered a rich source of diverse secondary metabolites with antimicrobial activity or cytotoxicity (Alburae et al., 2020). Notably, Emericella nidulans, the sexual state of a classic biosynthetic strain Aspergillus nidulans, was recently reported as an important source of highly methylated polyketides (Li et al., 2019) and isoindolone-containing meroterpenoids (Zhou et al., 2016) with unusual skeletons.
Animals ; Aspergillus nidulans ; Polyketides/chemistry* ; Anthozoa/microbiology* ; Anti-Infective Agents/pharmacology* ; Alkaloids

This study investigated the application of poly(N-isopropylacrylamide)-based interpenetrating network temperature-sensitive hydrogels (notation: IPNT) as the delivery vehicle for phage endolysin Lys84 and the potential of drug-loaded hydrogels as antimicrobial materials. Interpenetrating network temperature-sensitive hydrogels were prepared by free radical polymerization of sodium alginate and N-isopropylacrylamide. Drug-loaded hydrogels (IPNT-Lys84) were obtained by dry soaking method with the endolysin Lys84 of Staphylococcus aureus phage. The physical properties of the hydrogels with and without drug loading were characterized by infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry. The swelling and deswelling of the hydrogels as well as the release of endolysin Lys84 were investigated. Moreover, the antibacterial properties of IPNT-Lys84 hydrogels at different temperatures and concentrations of the drug solution were studied. The results showed that IPNT-Lys84 hydrogel had uniform pores and a low critical solubility temperature (LCST) of 32 ℃. The equilibrium swelling of the hydrogel was 30 g/g, and the water loss rate was 88% upon deswelling. The release rate of endolysin reached more than 70% within 6 h at 37 ℃. The bactericidal rate of IPNT-Lys84 hydrogel was over 99.9%. The research results showed the feasibility of using IPNT to deliver the endolysin Lys84, and IPNT-Lys84 hydrogel might be an effective antimicrobial material against multi-drug resistant Staphylococcus aureus.
Hydrogels/chemistry* ; Bacteriophages ; Methicillin-Resistant Staphylococcus aureus ; Temperature ; Anti-Infective Agents

Marine ecological niches have recently been described as "particularly promising" sources for search of new antimicrobials to combat antibiotic-resistant strains of pathogenic microorganisms. Marine organisms are excellent sources for many industrial products, but they are partly explored. Over 30 000 compounds have been isolated from marine sources. Bacteria, fungi, and cyanobacteria obtained from various marine sources secret several industrially useful bioactive compounds, possessing antibacterial, antifungal, and antimycobacterial activities. Sustainable cultivation methods for promising marine organisms and biotechnological processes for selected compounds can be developed, along with the establishment of biosensors for monitoring the target compounds. The semisynthetic modifications of marine-based bioactive compounds produce their new derivatives, structural analogs and mimetics that could serve as novel lead compounds against resistant pathogens. The present review focuses on promising antimicrobial compounds isolated from marine microbes from 1991-2013.
Anti-Infective Agents ; chemistry ; metabolism ; pharmacology ; Bacteria ; chemistry ; isolation & purification ; metabolism ; Fungi ; chemistry ; isolation & purification ; metabolism ; Seawater ; microbiology

The usage of Swietenia mahagoni, a popular medicinal plant in India and some African countries, dates back to ancient times for its curative properties in diseases like malaria, diabetes, and diarrhea. It is also used as an anti-pyretic, bitter tonic and astringent. Its pharmacological activities are being widely explored. Although many important groups of phytochemicals have been identified and isolated from various parts of the plant, most of these researches have been focused on seeds. Toxicological studies have established the safety of many of these plant extracts, and found insignificant side effects. Here we present a comprehensive review of all the pharmacological effects and constituent phytochemicals of the plant.
Animals ; Anti-Infective Agents ; pharmacology ; Anti-Inflammatory Agents ; pharmacology ; Humans ; Meliaceae ; chemistry ; Phytotherapy ; methods ; Plant Extracts ; pharmacology ; Plants, Medicinal ; chemistry ; Seeds ; chemistry