Eumitrins F-H: three new xanthone dimers from the lichen Usnea baileyi and their biological activities

Morusacerane: A new gammacerane triterpenoid from the trunk of Morus Alba linn. with α-glucosidase inhibitory activity

This phytochemistry investigation on the trunk of Morus alba L. resulted in the isolation of three triterpenoids, including a new gammacerane triterpenoid - morusacerane (1); along with two known compounds of betulinic acid (2) and ursolic acid (3). The structure elucidation was thoroughly conducted based on 1D, 2D-NMR and HRESIMS spectra, followed by a comparison with existing literatures. The evaluation on α-glucosidase inhibitory exhibited the great potential of the application of these isolated compounds in diabetes treatments. The results show that morusacerane (1), betulinic acid (2), and ursolic acid (3) demonstrate the strong inhibitory with the IC50 values of 106.1, 11.12, and 7.20 μM, respectively. All of these compounds interacted well with the allosteric site enzyme α-glucosidase MAL32 through H-bonds and hydrophobic interaction.

Tinctoric acid A-B, two new hopan-type triterpenoids from the Vietnamese lichen, Parmotrema tinctorum (Despr. ex Nyl.) hale with α-glucosidase inhibitory activity

Two new hopan-type triterpenoids, namely tinctoric acid A-B (1-2), were isolated from the lichen Parmotrema tinctorum (Despr. ex Nyl.) Hale. Their structures were elucidated by extensive spectroscopic analyses (1D and 2D NMR). The absolute configuration at C-22 of 1 was established through DP4 probability. Compounds 1-2 were evaluated for their inhibitory activity against α-glucosidase and found to be more potent than those of positive control (acarbose, IC50 168 µM) with values IC50 74.7 and 98.2 µM, respectively. Both of these compounds interacted well with enzyme α-glucosidase MAL32 through H-bonds and hydrophobic interaction.

Eumitrins I-K: three new xanthone dimers from the lichen Usnea baileyi

In the continuing discovery and structure elucidation of natural xanthone dimers, which are still rarely reported in absolute configuration, three new xanthone dimers, eumitrins I-K (1-3) were isolated from the lichen Usnea baileyi, a rich source of natural xanthone dimers. Their structures were elucidated unambiguously by spectroscopic analyses, including high-resolution electrospray ionization mass spectrometry (HRESIMS), 1D and 2D nuclear magnetic resonance spectroscopy (1D and 2D NMR). The absolute configuration of all three compounds was established through DP4 probability and ECD calculation. All compounds revealed weak activity for their enzymatic inhibition against α-glucosidase and tyrosinase, as well as antibacterial activity.

Relationship Between Alcohol Consumption and Risky Sexual Behaviors Among Adolescents and Young Adults: A Meta-Analysis

Objectives: Adolescents exposed to alcohol have increased risky sexual behaviors (RSBs); however, the association between alcohol consumption and RSBs has to be systematically and quantitatively reviewed. We conducted a meta-analysis of the literature to systematically and quantitatively review the association between alcohol consumption and RSBs in adolescents and young adults. Methods: We searched for qualified articles published from 2000 to 2020 and calculated pooled odds ratios (ORs) using the random-effect model. We also conducted meta-regression and sensitivity analyses to identify potential heterogeneity moderators. Results: The meta-analysis of 50 studies involving 465,595 adolescents and young adults indicated that alcohol consumption was significantly associated with early sexual initiation (OR = 1.958, 95% confidence interval (CI) = 1.635-2.346), inconsistent condom use (OR = 1.228, 95% CI = 1.114-1.354), and having multiple sexual partners (OR = 1.722, 95% CI = 1.525-1.945). Conclusion: Alcohol consumption is strongly associated with RSBs, including early sexual initiation, inconsistent condom use, and multiple sexual partners among adolescents and young adults. To prevent the adverse consequences of alcohol consumption, drinking prevention programs should be initiated at an early age and supported by homes, schools, and communities.