New Nostocyclophanes from Nostoc linckia
Abstract
Six new nostocyclophanes and four known compounds have been isolated from Nostoc linckia (Nostocaceae) cyanobacterial strain UTEX B1932. The new compounds, nostocyclophanes E–J (1–6), were characterized by NMR and MS techniques. The known compounds were nostocyclophanes B–D, previously isolated from this strain, and dedichloronostocyclophane D. Structural modifications on the new [7.7]paracyclophane analogs 1–5, isolated from the 80% methanol fraction, range from simple changes such as the lack of methylation or halogenation to more unusual modifications such as those seen in nostocyclophane H (4), in which the exocyclic alkyl chains are of different length; this is the first time this modification has been observed in this family of natural products. In addition, nostocyclophane J (6) is a linear analog in which C-20 is chlorinated in preparation for the presumed enzymatic Friedel–Craft cyclization needed to form the final ring structure, analogous to the biosynthesis of the related cylindrocyclophanes. Nostocyclophane D, dedichloronostocyclophane D, and nostocyclophanes E-J demonstrated moderate to weak growth inhibition against MDA-MB-231 breast cancer cells.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 31, 2023
- Source ID
- 10.3390/md21020101
Entities
People
- Casey S. Philbin
- Clay Wakano
- Jingqiu Dai
- Philip G Williams
- Wesley Y. Yoshida
Organizations
- National Institutes of Health
- National Science Foundation
- United States Department of Defense
- University of Hawaiʻi at Mānoa
- University of Nevada, Reno