The Siberian and European Larch Polar Alcohols of Neutral Substances of Woody Greens

Objective: The study aims to investigate and compare the composition of extractive substances extracted with petroleum ether from the woody greens of Siberian larch (Larix sibirica) and European larch (Larix decidua). Methods: The woody greens of Larix sibirica and Larix decidua were extracted with petroleum ether, and the composition of the extractive substances was analyzed. The alcohol fraction of neutral substances was identified and characterized, with specific attention to resinous substances, alcohol types, and diterpenoids. NMR spectroscopy was used to confirm the structures of the isolated compounds. Results and Discussion: The study found that Larix sibirica contained almost twice as much resinous substances (9.5%) as Larix decidua (5.2%). The alcohol fraction of neutral substances in Larix sibirica was 25.6%, which is twice as high as in Larix decidua (12.85%). In Larix decidua, the diol fraction dominated, constituting 30.0% of the alcohols, 3.3 times higher than in Larix sibirica. The alcohol compositions differed between the two species, with Larix decidua predominantly containing monoterpene alcohols (7.0%), while Larix sibirica had a higher proportion of sesquiterpene alcohols. Diterpenoids were the main component of the alcohol fraction in both species, with the aromatic diterpene alcohol dehydroabietinol (23.5%) being prevalent in Larix decidua, and its oxidized form, 15-hydroxymethyl dehydroabietate (23.1%), being predominant in Larix sibirica. Other diterpenoids, nor-diterpenoids, and specific alcohols such as 13-epimanool and phytol were also identified. Conclusions: The study provided a detailed comparison of the extractive substances from Larix sibirica and Larix decidua, revealing differences in resinous substances, alcohol compositions, and diterpenoid profiles between the two species. These findings contribute to a better understanding of the chemical diversity in the woody greens of Siberian and European larch.