A new iridoid skeleton from Galium asparagifolium and biological activity studies

This study identifies the detailed phytochemical content and biological effects of Galium as-paragifolium, for the first time and gained one new iridoid aglycone ( 1 ), seven known iri-doid glycosides ( 2-8 ), two flavonoids ( 9-10 ), and one carbohydrate derivative ( 11 ) to the liter-ature. The 1D-, 2D-NMR analyses and ESI-Mass allowed us to resolve the structure of new compound as (1S,4aS, 8aS)-pyrano[4, 3-c] pyran-1, 4a, 5, 7, 8, 8a- hexahydro- 1- hydroxy-3-( 2- hydroxyethyl)- 8- methyl-8-carboxylic acid namely galiumic acid. The compounds 1-11 and extracts from G. asparagifolium were investigated in terms of cytotoxic activity by MTT assay, antioxidant activ-ity by DPPH method and antimicrobial activity by DDT and BMM methods. While all compounds and extracts did not show remarkable cytotoxicity, they had variable antimicrobial activities for a variety of gram-positive/gram-negative bacteria and yeast strains. Besides that, most of the compounds showed an-tioxidant effect with a wide range of DPPH% inhibition values. The structure of the new compound was also elucidated by some computational studies. (c) 2021 Elsevier B.V. All rights reserved.