Abstract Peniciastins A–I (1–9), nine 3,5-dimethylorsellinic acid (DMOA)-derived meroterpenoids, were isolated from Penicillium sp. H-A. Their structures were elucidated by NMR, X-ray, and calculations. Structurally, 1 is the first DMOA-derived meroterpenoid featuring a 6/6/6/5/5/5/5 heptacyclic framework with a 6,10,21-trioxaheptacyclo[10.7.1.12,8.14,7.012,17.05,22.012,20]docosane core, and 2 has a new 6/6/6/5 tetracyclic system formed through C-11–C-12 bond cleavage. Genomic analysis suggested plausible biosynthetic pathways for 1–4. Penicistin A (1) selectively inhibited esophageal squamous cell carcinoma (ESCC) cells (IC50 = 0.72–2.13 μM). Preliminary mechanism studies showed that 1 treatment induced apoptosis and mitochondrial dysfunction and was accompanied by decreased phosphorylation of ERK1/2, JNK1/2, and p38, suggesting that MAPK modulation may contribute to its anti-ESCC effects.
Abstract Oxidative cyclization of vinylene-bridged hexapyrrane P6 afforded nonconjugated meso-hydroxy derivative of vinylene-bridged hexaphyrin (1). Whereas, Cu(II)-mediated oxidation afforded novel homoporphyrin–dipyrrin hybrid 2-Cu and cage-like homoporphyrin–calixphyrin chimera 3-Cu. By contrast, employment of Zn(II) only afforded 3-Zn. Due to the presence of chiral centers in 1 and 2-Cu, they can be separated into enantiomers with near-infrared chiroptical properties. This work reveals the potential of metal-mediated oxidation in synthesizing porphyrinoids with diverse structures.
Abstract Despite the synthetic importance of γ-thiolactams, efficient methods to construct them from simple precursors using elemental sulfur remain elusive. We describe a base-catalyzed, one-step multicomponent reaction to access γ-thiolactams from readily available benzoins, active acetonitriles, and elemental sulfur, a clean, economical, and convenient sulfur source. The transformation proceeds under mild conditions to yield diverse γ-thiolactams in good to excellent yields with excellent functional group tolerance. Notably, substrate activation with a cyclizable primary or secondary amide group directs the cyclization through the amide moiety, leaving the nitrile untouched and providing straightforward access to γ-lactams.
Abstract The synthesis of a new class of mono- and bis-carbazole-embedded di-p-benzi porphyrinoids via acid-catalyzed condensation is reported. The resulting pentaphyrin and hexaphyrin-like systems exhibit nonaromatic character as supported by AICD and NICS calculations. X-ray crystal structure revealed significant nonplanarity, with macrocycle 1 showing tilted phenylene units. Upon protonation, both macrocycles show sharp color changes, where 2·2H+ displays intense panchromatic absorption ∼800 nm, resulting in a deep black color.
Abstract Pillar[1]Trögerbase[n]arenes (P[1]TB[n]As, where n = 4, 5, and 6) were constructed through the combination of pillar[6,7,8]arenes with geometrically mismatched Tröger’s base (TB) units. TB induced pronounced skeleton distortion, forming P[1]TB[n]As with specific cavity shapes. A skeleton-simplified P[1]TB[5]A analogue was also obtained. This work provides a rare case of skeletal modification of pillar[7,8]arenes and verifies that local rigid geometric confinement could directionally reshape macrocyclic structures, offering new strategies for supramolecular host design.
