Org Lett. 2022 Sep 8. doi: 10.1021/acs.orglett.2c02701. Online ahead of print.

ABSTRACT

Four emestrin hybrid polymers, asperemestrins A-D (1-4, respectively), were isolated from the fungus Aspergillus nidulans. Asperemestrins A-C are the first examples of emestrin-sterigmatocystin heterodimers bearing a 7/5/6/6/5/5/6/6/6 nonacyclic system with a 2,5-diazabicyclo[2.2.2]octane-3,6-dione core, while asperemestrin D features an unprecedented 2,15-dithia-17,19-diazabicyclo[14.2.2]icosa-4,8-diene-12,18,20-trione core skeleton. Their structures were determined by extensive spectroscopic data, electronic circular dichroism calculations, and single-crystal X-ray diffraction. Asperemestrin B showed moderate cytotoxicity against cancer cell lines, including SU-DHL-2, HEPG2, and HL-60.

PMID:36074729 | DOI:10.1021/acs.orglett.2c02701

Food Res Int. 2022 Feb;152:110925. doi: 10.1016/j.foodres.2021.110925. Epub 2021 Dec 22.

ABSTRACT

Liupao tea is a representative Chinese dark tea. Stale-aroma type, betelnut-aroma type and fungal-aroma type were the main aroma types of Liupao tea. In this study, aroma profiles and fungal communities of the three aroma types of Liupao tea were examined by HS-SPME/GC-MS and Illumina MiSeq analysis. A total of 102 volatiles were identified and quantified in Liupao tea. Indicated by OPLS-DA analysis, six aroma compounds with stale, woody, roasted notes in stale-aroma type samples, five aroma compounds possessing smoky, minty, pungent notes in betelnut-aroma type samples, and nine aroma compounds owned minty, floral, fruity, woody, green notes in fungal-aroma type samples were responsible for the different aroma characteristics formation of Liupao tea. In addition, a total of 60 fungal genera were identified in Liupao tea. Aspergillus, Wallemia, Xeromyces were the predominant fungal genera in Liupao tea. Ten fungal genera, including Wallemia, Tritirachium, Debaryomyces, Trichomonascus, unclassified_o_Hypocreales in betelnut-aroma type, Rasamsonia, Candida, Blastobotrys, Acremonium in stale-aroma type, and Xeromyces in fungal-aroma type, were identified as the biomarkers in the three aroma types of Liupao tea. Furthermore, fungal genera including Aspergillus, Wallemia, Xeromyces, and Blastobotrys were identified as the core functional microorganisms contributing to the variation of volatile profiles based on O2PLS analysis. This study provided useful information on the key aroma compounds and core functional microorganisms that drive the different aroma characteristics formation of Liupao tea.

PMID:35181096 | DOI:10.1016/j.foodres.2021.110925