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Acylphloroglucinols are well-known Eucalyptus secondary metabolites which exhibit a variety of structures and bioactivities. The investigation of a crude acetone extract of Eucalyptus camaldulensis leaves led to the isolation of two new acylphloroglucinols, eucalypcamals O and P (1 and 2) together with seven phloroglucinols (3-9), and a benzene derivative (10). Their chemical structures were elucidated by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy. The absolute configurations of compounds 1 and 2 were established by comparison of experimental and calculated electronic circular dichroism (ECD) data. In the putative biosynthetic pathway, eucalypcamals O and P should be derived from hetero-Diels-Alder reaction between grandinol and trans-isoeugenol.

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Catheter-associated urinary tract infections (CAUTIs) are significant complications among catheterized patients, resulting in increased morbidity, mortality rates, and healthcare costs. Foley urinary catheters coated with synthesized silver nanoparticles (AgNPs) using Eucalyptus camaldulensis leaf extract were developed using a green chemistry principle. In situ-deposited AgNPs with particle size ranging between 20 and 120 nm on the catheter surface were illustrated by scanning electron microscopy. Atomic force microscopy revealed the changes in surface roughness after coating with nanoparticles. The coated catheter could significantly inhibit microbial adhesion and biofilm formation performed in pooled human urine-supplemented media to mimic a microenvironment during infections (p < 0.05). AgNPs-coated catheter exhibited broad-spectrum antimicrobial activity against important pathogens, causing CAUTIs with no cytotoxic effects on HeLa cells. A reduction in microbial viability in biofilms was observed under confocal laser scanning microscopy. A catheter bridge model demonstrated complete prevention of Proteus mirabilis migration by the coated catheter. Significant inhibition of ascending motility of Escherichia coli and P. mirabilis along the AgNPs-coated catheter was demonstrated in an in vitro bladder model (p < 0.05). The results suggested that the AgNPs-coated urinary catheter could be applied as an alternative strategy to minimize the risk of CAUTIs by preventing bacterial colonization and biofilm formation.

Annually, a great number of bananas are produced, and those that do not satisfy commercialization criteria are discarded, resulting in a considerable amount of agricultural waste. This work aimed at valorizing rejected unripe Musa sapientum fruit by microwave-assisted extraction using glycerol-ethanol mixtures for development of cosmeceuticals. The fruit extract exhibited potent radical scavenging activity towards 2,2-diphenylpicrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays in a concentration-dependent manner. Ferric reducing power was 199.13 μM FeSO4/mg extract. Total phenolic content was 39 mg gallic acid equivalent/100 g extract and total flavonoid content was 26 mg quercetin equivalent/100 g extract. Vitamin C and E contents of the extract were 10.47 and 4.77 mg/100 g, respectively. The extract exhibited potent antibacterial activity against wide range of bacterial pathogens. The extract significantly reduced nitric oxide production in RAW 264.7 cells (p < 0.05). Biocompatibility assessment of the extract with L929 fibroblast cells demonstrated no toxic effects. M. sapientum-loaded serum significantly inhibited DPPH scavenging activity with a value of 50.62% when compared with commercially-available product (p < 0.05). The serum significantly suppressed tyrosinase activity about 37.46% (p < 0.05). This finding implies that M. sapientum has a high potential to be used as a depigmenting agent.