Atropisomeric meroterpenoids with rare triketone-phloroglucinol-terpene hybrids from Baeckea frutescens

Abstract

Compounds 1–4 represent the first examples of natural atropisomeric meroterpenoids with a rare triketone-phloroglucinol-terpene skeleton.

Structures and Bioactive Properties of Myrtucommulones and Related Acylphloroglucinols from Myrtaceae

“…Further intramolecular reactions could involve the phenolic or ketonic group to form, respectively, pyranic or furanic rings. Prenylation has also been reported for compounds from this class [25,27,45,49,52].…”

“…Moreover, it inhibited the proliferation of T-cells, which is a relevant effect for the prevention or treatment of autoimmune disorders, such as Parkinson’s disease, rheumatoid arthritis, and diabetes [38]. Additionally, inhibitory effects on nitric oxide production after lipopolysaccharide stimulation in murine macrophage cells (RAW 264.7) have been documented for baefrutones A–D ( 64 – 67 ) [52], and for tomentodione T ( 61 ) and rhodomyrtosones B, G, and I ( 19 , 43 , 22 ) [50].…”

Meroterpenoids: A Comprehensive Update Insight on Structural Diversity and Biology

“…Moreover compounds 188-191 displayed anti-inflammatory effects towards NO production with IC 50 = 9.1 to 18.0 µM (Table 2), while meroterpenoids 192 and 193 were not active. Notably compounds 188-191 were more potent than the positive control L-NMMA (IC 50 = 30.9 µM) [69]. Filicinic acid-based meroterpenoids, the hyperjaponols A-G (194-200) (Figure 22) were isolated from Hypericum japonicum and comprise 6/6/7/5, 6/6/11, or 6/6/10 sized ring frameworks.…”

Recent advances in the synthesis of natural products containing the phloroglucinol motif

“…Using natural baeckenon B ( 84 ) isolated from Baeckea frutescens , the syntheses of two biosynthetically related phloroglucinol–sesquiterpenes, baefrutones E and F ( 235 and 236 ), were accomplished by the Wang group (Scheme 42). 155 The regioselective oxidative hetero-Diels–Alder reaction between 84 and 230 proceeded smoothly with TEMPO and Ag 2 O, providing the two natural products in moderate yields.…”