Chemical modifications of a natural xanthone and antimicrobial activity against multidrug resistant Staphylococcus aureus and cytotoxicity against human tumor cell lines

Abstract

A series of 15 ω-aminoalkoxylxanthones containing methyl, ethyl, propyl, tert-butylamino and piperidinyl moieties were synthesized from a natural xanthone isolated from a lichen species. These compounds were tested for their in vitro antibacterial properties against Gram-positive and Gram-negative bacteria and cytotoxicity against a number of human tumor cell lines was too evaluated. The newly synthesized derivatives revealed selective activity against Staphylococcus aureus (Gram-positive), and the most promising results are for a multidrug resistant strain, for which six of these compounds showed good activity (MICs 4 µg/mL). Many derivatives inhibited tumor cells growth and most compounds were active on multiple lines.

Actinobacteria Isolated from an Underground Lake and Moonmilk Speleothem from the Biggest Conglomeratic Karstic Cave in Siberia as Sources of Novel Biologically Active Compounds

“…Thus, the Streptomycetes spp genera strains isolated from moonmilk speleothem demonstrated antibacterial and antifungal activities. In general, the observed bioactivity of crude extracts of isolated strains broadly consistent to bioactivity of a crude extracts obtained from other published bacterial isolates [ 35 – 36 ] but couldn’t be compared with purified known commercial antibiotics. The materials about activity of some known antibiotics available online in [Clinical Laboratory Improvement Amendments, https://www.cms.gov/Regulations-and-Guidance/Legislation/CLIA/index.html?redirect=/clia ; https://www.cms.gov/regulations-and-guidance/legislation/clia/downloads/sc04163.pdf ].…”

Uncommon Chlorinated Xanthone and Other Antibacterial Compounds from the Lichen Cladonia incrassata

“…4) showed correlations of H-8 (δ H 7.73) with carbonyl C-9 (δ C 181.2), supporting the unusual position of this aromatic proton at C-8. Also, the HMBC experiment highlighted three correlations for CH 3 -7, as generally observed for aromatic methyl groups [20,21]. The carbon at δ C 141.2 was placed at position C-5 because of a lack of correlations with H-8 and CH 3 -7.…”

Small Molecular Mimetics of Antimicrobial Peptides as a Promising Therapy To Combat Bacterial Resistance

“…Xanthones are naturally occurring polyphenolic secondary metabolites that are abundant in lichens, bacteria, fungi, and higher plant families (Figure ). Numerous research groups have pursued the unique structural scaffold for developing drug candidates, particularly antitumor drugs. , In addition, α-mangostin, a xanthone derivative, has demonstrated antimicrobial activity. , It was intriguing that α-mangostin exhibited antimicrobial properties such as rapid bactericidal action and the low likelihood of resistance development, which are characteristics of AMPs. However, the hydrophobic nature of the xanthone scaffold prevents α-mangostin from possessing adequate selectivity over mammalian cells.…”

“…153 Numerous research groups have pursued the unique structural scaffold for developing drug candidates, particularly antitumor drugs. 154,155 In addition, α-mangostin, a xanthone derivative, has demonstrated antimicrobial activity. 156,157 It was intriguing that α-mangostin exhibited antimicrobial properties such as rapid bactericidal action and the low likelihood of resistance development, which are characteristics of AMPs.…”