Diacyl Disulfide: A Reagent for Chemoselective Acylation of Phenols Enabled by 4‑(<i>N</i>,<i>N</i>‑Dimethylamino)pyridine Catalysis

A general and excellent acylation reagent, diacyl disulfide, was uncovered for efficient ester formation enabled by DMAP (4-(<i>N</i>,<i>N</i>-dimethylamino)­pyridine) catalysis. This protocol offered a promising synthetic platform on site-selective acylation of phenolic and primary aliphatic hydroxyl groups, which greatly expanded the realm of protecting group chemistry. The importance of the reagent was also reflected by its excellent moisture tolerance, high efficiency, and potential in synthetic chemistry and biologically meaningful natural product modification

Secondary metabolites from the <i>Colletotrichum gloeosporioides</i> A12, an endophytic fungus derived from <i>Aquilaria sinensis</i>

<p>Two new cyclohexene derivatives colletotricones A and B (<b>1</b> and <b>2</b>) and a new thiazole derivative colletotricole A (<b>5</b>), along with six known natural metabolites were isolated from the extract of <i>Colletotrichum gloeosporioides</i> A12, an endophytic fungus derived from <i>Aquilaria sinensis</i>. Among them, the colletotricones A and B possess a cyclohexenone skeleton, whereas the colletotricole A is a thiazole derivative. Their structures were fully assigned with the aid of extensive spectroscopic analysis and data from the literature. Moreover, cytotoxic activity <i>in vitro</i> of compounds <b>1</b> and <b>3–9</b> were evaluated against MCF-7, NCI-H460, HepG-2 and SF-268 tumour cell lines. The new compound <b>1</b> exhibited growth inhibitory activity against all the four tumour cell lines with IC₅₀ values ranging from 15.7 to 46.8 μM.</p

Two new 12-membered macrolides from the endophytic fungal strain <i>Cladosprium colocasiae</i> A801 of <i>Callistemon viminalis</i>

<p>Two new polyketide metabolites, the 12-membered macrolides 4-hydroxy-12-methyloxacyclododecane-2,5,6-trione (<b>1</b>) and 12-methyloxacyclododecane-2,5,6-trione (<b>2</b>), were isolated from the endophytic fungal strain <i>Cladosprium colocasiae</i> A801 of the plant <i>Callistemon viminalis</i>, together with five known derivatives<i>.</i> Their structures were fully characterized by means of detailed spectroscopic analysis for new structures, and in comparison with published data for known compounds. The antibacterial, cytotoxic, and α-glucosidase inhibitory activities of the new compounds <b>1</b> and <b>2</b> were evaluated.</p