A Racemic Synthesis of the Novel Antibacterial Agent Juglomycin A

Unified Approach toward Syntheses of Juglomycins and Their Derivatives

A unified and common intermediate strategy for syntheses of juglomycins and their derivatives is reported. The use of a 1,4-dimethoxynaphthalene derivative as a key intermediate enabled easy access to various juglomycin derivatives. In this study, juglomycins A-D, juglomycin C amide, khatmiamycin and its 4-epimer, and the structure proposed for juglomycin Z were synthesized from this intermediate. The absolute configuration of natural khatmiamycin has been established to be 3R,4R through our synthesis. Unfortunately, the spectroscopic data for synthetic juglomycin Z were not consistent with the data reported for the natural one, strongly suggesting a structural misassignment.

Exploiting photooxygenations mediated by porphyrinoid photocatalysts under continuous flow conditions

Photooxygenations of naphthols under continuous flow conditions using porphyrinoids as photocatalysts are described. Reaction conditions, long-term experiments and scope were performed, thus allowing the production of substituted naphthoquinones.

Design, Synthesis, and Biological Evaluation of New Territrem B Analogues

Some 23 analogues of the potent acetylcholinesterase (AChE) inhibitor territrem B (1) were designed, synthesized, and tested for their biological activities. Some of the new synthetic derivatives exhibited IC50 values for AChE inhibition in the upper micromolar range. Molecular-modeling studies indicated that a planar conformation seems to be crucial for AChE inhibition. The two N-atoms of the piperazine moieties in 5o, 5p, and 5r might further enhance the inhibitory effects. The cytotoxicities of selected compounds against six human tumor cell lines were also determined.