Synthesis of the proposed structure of sibiriaester B and evaluation of its immunomodulatory properties

Abstract

Herein, we report a concise synthesis of the proposed structure of sibiriaester B, a novel antioxidant phenyl caffeate derivative isolated from the leaves of Armeniaca sibirica. Proposed sibiriaester B was obtained via simple esterification between the known TBS‐protected caffeic acid and the commercially available methyl 4‐hydroxybenzoate, and subsequent deprotection. However, the NMR spectral data of the synthesized sibiriaester B were not consistent with those in previous reports. The structure of the synthesized sibiriaester B was confirmed using combined 2D‐NMR analysis, including COSY, HSQC, and HMBC. The synthesized sibiriaester B was observed to exhibit more potent immunomodulatory activity in murine epidermal T cells than p‐hydroxyphenyl caffeate, an immunomodulatory natural caffeate derivative, as treatment with sibiriaester B significantly reduced the production of interleukin 13 by murine epidermal T cells at lower concentrations than p‐hydroxyphenyl caffeate.

Synthesis and Dopaminergic Neuroprotective Activity of the Proposed Structure of Bassiamide A, a Caffeamide Alkaloid Derived from Bassia Indica Wight

“…[8,11,12] We have intensively investigated the synthetic methods and biological applications of natural caffeic acid ester derivatives, such as p-hydroxyphenylcaffeate and sibiriaester B. [13,14] Despite exhibiting promising in vitro biological activities, their metabolic instability prompted us to shift our attention to natural caffeamide derivatives such as bassiamide A (1, Figure 1). Bassiamide A is a novel caffeamide alkaloid isolated by Othman et al from the aerial part of Bassia indica Wight, a wild plant used as a medicinal herb for the treatment of several diseases.…”

“…For these reasons, not only bioisosteric modification of caffeic acid esters to corresponding amides, but natural caffeamide derivatives also have attracted the interest of synthetic and medicinal chemists [8,11,12] . We have intensively investigated the synthetic methods and biological applications of natural caffeic acid ester derivatives, such as p ‐hydroxyphenylcaffeate and sibiriaester B [13,14] . Despite exhibiting promising in vitro biological activities, their metabolic instability prompted us to shift our attention to natural caffeamide derivatives such as bassiamide A ( 1 , Figure 1).…”

Green deep‐UV photoresist based on chitosan for microelectronics

“…However, the vast majority of industrial photoresists are using organic solvents, which strongly limits the choice of suitable PAG active in the DUV region around 200 nm. 30 Some works are describing the crosslinking of watersoluble poly(vinyl alcohol) photoresists with PAG at 254 and 248 nm 31,32 or a water-developable chemically amplified negative-tone resist for 248 nm, 33 but no reports have been identified for 193 nm applications.…”