Organics

The increasing prevalence of antimicrobial resistance has stimulated interest in non-antibiotic small molecules that can restore or potentiate the activity of established antibacterial agents. In this study, a focused series of low-molecular-weight chromene derivatives was synthesized, structurally characterized, and evaluated primarily as antibacterial adjuvants rather than as stand-alone antibiotics. The experimental strategy was designed to distinguish intrinsic antibacterial activity from potentiating activity in combination with a partner antibiotic. Initial susceptibility testing was followed by combination experiments in selected bacterial strains, with particular emphasis on changes in the minimum inhibitory concentration (MIC) of meropenem or doripenem in the presence of each test compound. Broth microdilution combination assays demonstrated that compound 3a significantly reduced the MIC of meropenem and doripenem against methicillin-resistant Staphylococcus aureus (MRSA). The observed adjuvant effect suggests that chromene scaffolds may serve as promising candidates for the development of next-generation β-lactam enhancers aimed at overcoming carbapenem resistance.

East Asian crowberry has been reported under Empetrum nigrum var. japonicum and E. nigrum subsp. asiaticum. This critical narrative review evaluates taxonomy, phytochemistry, and pharmacological evidence from Korean, Japanese, and Chinese source-reported material in the context of the wider Empetrum literature. Reassessment of primary reports identified a broader East Asian chemical evidence base than previously summarized, including methylated, methoxylated, and hydroxylated chalcone/dihydrochalcone derivatives, bibenzyls, triterpenoids, flavonoids, and related constituents. These reports raise the possibility of East Asian chemotypic differentiation, but direct comparative metabolomics using authenticated populations and standardized methods has not established their geographic specificity or abundance. Reported pharmacological activities include antioxidant and cytoprotective effects, nitric oxide and α-glucosidase inhibition, cancer cell cytotoxicity, anti-angiogenic activity in an in ovo chorioallantoic membrane model, and limited mammalian in vivo evidence, including a Korean carbon tetrachloride-induced hepatotoxicity model and a Chinese alcoholic fatty liver rat model. Evidence strength varies substantially because botanical authentication, extract standardization, dose–response reporting, and independent replication are inconsistent. The available literature therefore provides preliminary evidence consistent with potential East Asian chemotypic differentiation but does not establish a discrete chemotypic boundary. Priority needs are taxonomic authentication, harmonized chemical profiling, quantitative marker validation, extract standardization, compound-level testing, and independent pharmacological replication.

Indolo[2,3-b]quinoxalines and their N-substituted derivatives exhibit anticancer activity. In this work, a convenient two-step protocol comprising base-promoted aldol condensation followed by oximation was used for the synthesis of novel β-hydroxy oximes from heterocyclic ketones. The oximes were obtained as Z/E mixtures with one isomer predominating, and DFT calculations confirmed the E-configuration as thermodynamically preferred by 1.0–1.4 kcal/mol. High isomerization barriers (49–56 kcal/mol) via nitrogen inversion indicate kinetic stability of the β-hydroxy oximes at room temperature. The tryptanthrin-based β-hydroxyketone 5 (6-hydroxy-6-(2-oxopropyl)indolo[2,1-b]quinazolin-12(6H)-one) proved most potent, with IC₅₀ values of 58 µM (MCF-7), 59 µM (PC-3) and 135 µM (SKOV-3); its derivative 6-hydroxy-6-(2-(hydroxyimino)propyl)indolo[2,1-b]quinazolin-12(6H)-one oxime (compound 8) was less effective, while other derivatives were inactive or showed only weak effects. MCF-7 and PC-3 cells were more sensitive than SKOV-3 cells. Hence, compounds 5 and 8 are promising leads for further SAR optimization and anti-cancer evaluation.