Armochaetoglobins K–R, Anti‐HIV Pyrrole‐Based Cytochalasans from Chaetomium globosum TW1‐1

Abstract

Eight rare pyrrole‐based cytochalasans, termed armochaetoglobins K–R (1–8), along with three known analogues (9–11), were isolated from the solid culture broth of Chaetomium globosum TW1‐1, a symbiotic fungus derived from the medicinal terrestrial arthropod Armadillidium vulgare. Their structures were elucidated using a combination of spectroscopic analysis, a single‐crystal X‐ray diffraction experiment, and an electronic circular dichroism (ECD) calculation. Compounds 4–8 represent the first examples of chaetoglobosin‐type cytochalasans with an sp3 methine carbon at C‐18. All of the isolates were evaluated for their anti‐HIV activities in vitro, and compounds 2–4, 7, 8, and 10 showed significant anti‐HIV activities, with EC50 values ranging from 0.11 to 0.55 μM, and selectivity index (SI) values ranging from 12.33 to 75.42. A plausible biosynthetic pathway was proposed to explain the origin of the pyrrole ring.

Asperflavipine A: A Cytochalasan Heterotetramer Uniquely Defined by a Highly Complex Tetradecacyclic Ring System from Aspergillus flavipes QCS12

“…Cytochalasans are a class of fungal metabolites characterized by high structural diversity and a broad spectrum of bioactivity, including cytotoxic, immunomodulatory, and antiviral activity . An extensive literature investigation revealed that more than 300 cytochalasans have been identified to date, and a number of excellent studies have been reported in recent years .…”

Bioactive Chaetoglobosins from the Mangrove Endophytic Fungus Penicillium chrysogenum

“…To date, about 80 chaetoglobosins have been found from some fungi belonging to the genera Chaetomium [5,6,7], Discosia [8], Cylindrocladium [9], Penicillium [10,11], Calonectria [12], Diplodia [13], and Phomopsis [14], most belonging to the genus Chaetomium . Many of them have been reported to possess diverse bioactivities, including cytotoxicity to tumor cell lines [15,16], anti-HIV [17], antimicrobial [18], phytotoxic activity [19], and so on. Endophytes are fungi or bacteria that live in the healthy tissues of living plants without causing discernible disease to the host [20].…”

Adsorption of phosphate from aqueous solution by Zr(IV)‐crosslinked quaternized chitosan/bentonite composite

“…The partial substitution of Al 31 for the tetrahedral Si 41 and Mg 21 makes the layers negatively charged, which is neutralized by exchangeable cations in the interlayer space. Based on these properties of HACC, it has been applied for the preparation of composite films [16], adsorbent material [17], and nanocomposites [18,19]. are in the interlayer of natural MMT.…”