[Structure: see text]. Citrinadin A (2) is a pentacyclic indolinone alkaloid isolated from the cultured broth of a fungus, Penicillium citrinum, which was separated from a marine red alga. The absolute stereochemistry of the pentacyclic core in 2 and its new congener, citrinadin B (1), was elucidated by analysis of the ROESY spectrum for the chlorohydrin derivative (3) of 1 as well as comparison of the electronic circular dichroism (ECD) spectra for 1 and 2 with those of known spirooxiindole alkaloids. On the other hand, the absolute configuration at C-21 bearing an epoxide ring was assigned as S by comparison of the vibrational circular dichroism (VCD) spectra of 1 with those of model compounds 2S- and 2R-2,3-epoxy-3,3-dimethyl-1-phenylpropan-1-one (4a and 4b, respectively).

Download full-text PDF

Source
http://dx.doi.org/10.1021/jo051499oDOI Listing

Publication Analysis

Top Keywords

absolute stereochemistry
8
circular dichroism
8
stereochemistry citrinadins
4
citrinadins marine-derived
4
marine-derived fungus
4
fungus [structure
4
[structure text]
4
text] citrinadin
4
citrinadin pentacyclic
4
pentacyclic indolinone
4

Similar Publications

Asymmetric Synthesis, Structure Determination, and Biologic Evaluation of Isomers of TLAM as PFK1 Inhibitors.

ACS Med Chem Lett

January 2025

Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan.

Inhibiting phosphofructokinase-1 (PFK1) is a promising approach for treating lactic acidosis and mitochondrial dysfunction by activating oxidative phosphorylation. Tryptolinamide (TLAM) has been shown as a PFK1 inhibitor, but its complex stereochemistry, with 16 possible isomers complicates further development. We conducted an asymmetric synthesis, determined the absolute configurations, and evaluated the PFK1 inhibitory activity of the TLAM isomers.

View Article and Find Full Text PDF

Model P-chirogenic phosphonates derived from isopinocampheol, offering an excellent experimental system for studying chirality on the phosphorus chiral center, were studied using a set of chiroptical methods including ECD, VCD and ROA. Thanks to their rigidity, limiting the number of possible conformers, we successfully correlated the experimental UV-vis/ECD, IR/VCD and Raman/ROA results with DFT calculations. This allowed us to confidently assign the absolute configuration of our models, and our assignment is consistent with X-ray diffraction (XRD) data.

View Article and Find Full Text PDF

Mycolactone is a complex macrolide toxin produced by , the causative agent of Buruli ulcer. The aim of this paper is to review the chemistry, biosynthetic, and synthetic pathways of mycolactone A/B to help develop an understanding of the mode of action of these polyketides as well as their therapeutic potential. The synthetic work has largely been driven by the desire to afford researchers enough (≥100 mg) of the pure toxins for systematic biological studies toward understanding their very high biological activities.

View Article and Find Full Text PDF

Chemistry and biology of natural stilbenes: an update.

Nat Prod Rep

December 2024

Chinese Pharmacopoeia Commission, Beijing 100061, China.

Covering: 2009 up to the end of 2023Stilbenes, an emblematic group of polyphenols, have attracted the attention of numerous researchers owing to their intriguing polycyclic architectures and diverse bioactivities. In this updated review, natural stilbenes were analysed, especially oligomeric stilbenes, which are an emblematic group of polyphenols that harbor intriguing polycyclic architectures and diverse bioactivities compared with those previously anticipated. Oligomeric stilbenes with unique skeletons comprise a large majority of natural stilbenes owing to their structural changes and different substitutions on the phenyl rings.

View Article and Find Full Text PDF

Structurally diverse chromane meroterpenoids from Rhododendron capitatum with multifunctional neuroprotective effects.

Eur J Med Chem

February 2025

Shaanxi Key Laboratory of Natural Products & Chemical Biology, Shaanxi Engineering Center of Bioresource Chemistry & Sustainable Utilization, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, 712100, PR China. Electronic address:

Eleven new chromane meroterpenoids (1-11), along with 24 known ones (12-35) were isolated from Rhododendron capitatum, a Tibetan medicine. Their structures were determined via extensive spectroscopic methods. The absolute configurations of 1 and 2 were determined by comparison of the experimental and theoretically calculated ECD data.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!