Two Novel Ceramides with a Phytosphingolipid and a Tertiary Amide Structure from Zephyranthes candida

Two novel ceramides, Candidamide A ( 1 ) with a phytosphingolipid structure, and Candidamide B ( 2 ) with a tertiary amide structure, together with 12 known compounds ( 3–14 ) have been isolated from the bulbs of Zephyranthes candida , The structures of 1 and 2 have been elucidated to be 1,3,5,6‐tetrahydroxy‐2‐(2′‐hydroxytetracosanoyl amino)‐8‐( E )‐octadecadiene ( 1 ) and (2 S ,3 S ,4 R ,8 E ,2′ R )‐2‐[ N ‐(2′‐hydroxyoctadecanoyl)‐ N ‐(1′′,2′′‐dihydroxyethyl)‐amino]‐8‐hexacosene‐1,3,4‐triol ( 2 ) on the basis of spectroscopic evidence including IR, MS, NMR ( 1 H‐NMR, 13 C‐NMR, DEPT, 1 H– 1 H COSY, HSQC, HMBC). The known compounds were identified as (2 S )‐3′,7‐dihydroxy‐4′‐methoxyflavan ( 3 ), (2 S )‐4′‐hydroxy‐7‐methoxyflavan ( 4 ), (2 S )‐4′,7‐dihydroxyflavan ( 5 ), 7‐hydroxy‐3′, 4′‐methylenedioxyflavan ( 6 ), ambrettolide ( 7 ), β‐sitostero1 ( 8 ), β‐daucosterin ( 9 ), rutin ( 10 ), pancratistatin ( 11 ), lycorine ( 12 ), haemanthidine ( 13 ), and haemanthamine ( 14 ). In the antimicrobial assay, candidamide A ( 1 ) and candidamide B ( 2 ) displayed moderate activities against bacteria Staphylococcus aureus and Escherichia coli , and fungi Aspergillus niger , Candida albicans and Trichophyton rubrum .