A new antibacterial benzophenone glycoside fromPsidium guajava(Linn.) leaves

Abstract

Bioactivity-guided fractionation of methanol extract from the leaves of Psidium guajava L. (Myrtaceae) yielded a new benzophenone glycoside, Guajaphenone A (2) together with two known compounds, Garcimangosone D (1) and Guaijaverin (3). Their structures were elucidated by analysis of spectroscopic data including 1D and 2D NMR and electrospray ionisation mass spectrometry (ESI-MS). The isolated compounds were screened against standard strains of Gram-positive and Gram-negative bacteria using broth dilution assay method, and the MIC values determined and compared with reference antibiotic ceftriaxone. They were found to have significant antibacterial activities against Escherichia coli and Staphylococcus aureus with all of them showing better activities against S. aureus, but displaying weaker activities, in comparison to ceftriaxone. However, despite reduced effect of these compounds against the organisms, this work opens the perspective to use these molecules as 'leads' for the design of novel and selective drug candidates for some tropical infectious diseases.

Hyperelatosides A–E, biphenyl ether glycosides from Hypericum elatoides, with neurotrophic activity

“…The remaining compounds were elucidated on the basis of NMR and ESIMS data analysis as well as by comparison with literature data. They were identified as 3,5-dihydroxy-4-methoxyxanthone (7), 16 1,5,6-trihydroxy-7-methoxyxanthone (8), 17 1,3,7-trihydroxy-2-(2-hydroxy-3-methyl-3-butenyl)-xanthone (9), 18 2,4-dihydroxy-3-methyl-6- O -β- d -glucopyranosyl benzophenone (10), 19 garcimangosone D (11), 20 1-(2-methylbutyryl)-phloroglucinol-glucopyranoside (12), 21 quercetin 3- O -α- l -rhamnopyranoside (13), 22 quercetin 3- O -β- d -galactopyranoside (14), 23 and kaempferol 3- O -α- l -rhamnopyranoside (15) 24 (Fig. S54, ESI † ).…”

UV cross-linked polyvinylpyrrolidone electrospun fibres as antibacterial surfaces

“…This ability of BP to form covalent bonding with copolymers and greatly influence the gelation efficiency due to radical generation on the polymer backbone after UV irradiation was already exploited in the literature [28]. Benzophenone and its derivatives were also found to have significant antibacterial activity [29][30][31]. There are number of synthetic biocides that inhibit the growth of bacteria [32,33], however, the substances of natural origin secreted by living organisms including hydrolytic enzymes which act more specifically, are considered as more attractive class of biocidal agents due to their biological nature [34].…”

UJI AKTIVITAS ANTIBAKTERI FRAKSI ETIL ASETAT DAUN JAMBU BIJI (Psidium guajava L.) TERHADAP BAKTERI PENYABAB KARIES GIGI Streptococcus sanguis

“…Ekstrak daun jambu biji putih mengandung senyawa saponin, tanin, steroid, flavonoid, alkaloid dan triterpenoid [5]. Flavonoid dari isololat daun jambu biji memiliki antibakteri terhadap S. aureus dan E. Coli [9]. Namun dari fraksi daun jambu biji (Psidium guajava Linn.)…”