A possible glycosidic benzophenone with full substitution on B-ring from Psidium guajava leaves

Abstract

Bidimensional NMR analysis may be a useful tool to resolve the structure of chemical compounds also in mixture. This letter would demonstrate how these techniques could be applied e.g. to the reported case on identification of benzophenone glycoside from Psidium guajava. A tentative structure for the secondary component, not yet described, was possibly proposed on the basis of observation and critic review of available 1D and 2D NMR spectra.

Chemical Composition, Cytotoxic and Antibacterial Activities of Essential Oils of Cultivated Clones of Juniperus communis and Wild Juniperus Species

“…communis cultivated clones with the wild Juniper species. Sixty‐one diverse volatile components were detected in examined samples ( Table ) . The quantification data obtained from GC accounted 82.5 – 95.7% of the total EOs.…”

“…The major oxygenated monoterpenes detected were cis ‐sabinene hydrate and 4‐terpineol. The oxygenated sesquiterpenes were found as τ ‐cadinol and α ‐cedrol ( Table ) …”

“…Detailed description for C‐1, C‐2, C‐3, C‐4, C‐5, C‐6, C‐7, JC, JR and JI presented in Table . [c] RI: Retention indices; MS: mass spectra in electronic impact and major compounds confirmed using 13C‐NMR . Values are given as mean ± standard deviation ( n = 3).…”

“…On the basis of TLC profiles, similar fractions were combined to obtain 14 major fractions. The confirmation of major volatile components ( α ‐pinene, sabinene, β ‐myrcene, limonene, cis ‐sabinene hydrate, α ‐terpinolene, linalool and 4‐terpineol) were further accomplished by 13 C‐ (150 MHz) and 1 H‐NMR (600 MHz), DEPT, HSQC and HMBC on Bruker Avance instrument, using CDCl 3 ( Table ) by comparing with those of references ( Supporting Information ).…”

Iridoids of Chemotaxonomy Relevance, a New Antirrhinoside Ester and Other Constituents from Kickxia spuria subsp. integrifolia (Brot.) R.Fern.

“…The correspondence of observed resonances with assigned nuclei was conducted following an approach already applied in our recent studies which permits to unambiguously assign the resonances also in the case of mixtures and consisting in the crosscheck of heteronuclear correlations visible in both HSQC and HMBC experiments. Diagnostic HMBCs of compound 12 are depicted in Figure .…”