Practical isolation of polygodial from Tasmannia lanceolata: a viable scaffold for synthesis

Abstract

Polygodial, a valuable sesquiterpene dialdehyde featuring an epimerizable stereocenter was efficiently extracted and isolated in gram-scale quantities (3.3% w/w) from Tasmannia lanceolata (Tasmanian native pepper) via a recently developed rapid pressurised hot water extraction (PHWE) technique that utilises an unmodified household espresso machine. This method was compared to the maceration of T. lanceolata under a range of conditions. Polygodial was used to achieve semi-syntheses of closely related sesquiterpene natural products drimendiol, (-)-drimenol, (+)-euryfuran, and some non-natural derivatives.

Pressurized Hot Water Extraction as a Viable Bioprospecting Tool: Isolation of Coumarin Natural Products from Previously Unexamined Correa (Rutaceae) Species

“…Furthermore, during the extraction process, epoxide ring‐opening of potentially reactive functional groups was not observed (as determined by 1 H NMR analysis of the crude extracts containing coumarins 6–9 ). This underscores the mildness of this extraction technique and is consistent with previous observations in our germane studies on the isolation of natural products 2 and 4 featuring somewhat sensitive functional groups . Therefore, we have demonstrated that the PHWE methodology that we have developed is amenable to the efficient identification of plant species that can provide complex organic scaffolds that are potentially useful synthetically.…”

Bitter melon protects against ER stress in LS174T colonic epithelial cells

“…Active ingredients were extracted from BM (Chinese variety; sourced from local vegetable super market in Hobart, Tasmania, Australia labelled as bitter melon) by pressurised hot water using a modification of a method previously described for natural product isolation [27, 28]. …”

Development and Applications of Water‐based Extraction Methods in Natural Products Isolation Chemistry

“…PHWE (35% v/v EtOH/H 2 O) facilitated the isolation of gramscale quantities of the drimane dialdehyde polygodial (39; 3.3% w/w) from Tasmanian pepperberry leaves (Tasmannia lanceolata) (Figure 11). [41] Access to synthetically-useful quantities of chiral scaffold 39 by this approach allowed for the preparation of related natural products via semi-synthesis, [41] novel Nheterocycles, [42] and new biologically-active molecules. [43,44] PHWE was found to be superior in extraction efficiency when directly compared to a commercial ASE system.…”

“…[43,44] PHWE was found to be superior in extraction efficiency when directly compared to a commercial ASE system. [41] Specifically, the optimal extraction temperature and solvent system (EtOH/ H 2 O) parameters for the extraction of polygodial from T. lanceolata were determined for the ASE system, with varying ethanol/water solvent mixtures (15%, 25%, and 35% v/v EtOH/ H 2 O), and temperatures (70°C, 90°C, 110°C, 130°C). The optimal extraction conditions (90°C using 35% v/v EtOH/H 2 O) are consistent with the PHWE conditions.…”

“…At elevated temperatures, epimerisation of polygodial (35) to epi-polygodial (40) was observed with the ASE method (35% v/v EtOH/ H 2 O solvent system), as indicated by quantitative 1 H NMR spectroscopic analysis of the respective extracts. [41] For example, epimerisation of polygodial occurred using ASE at 70, 90 and 110°C (up to 91 : 9 39 : 40), with significant epimerization at 130°C (78 : 22 39 : 40). At these higher temperatures (� 90°C) decomposition of polygodial was also observed, forming more impurities and resulting in a lower combined yield of sesquiterpenoids 39 and 40.…”