{'fraction_non_alphanumeric': 0.03773584905660377, 'fraction_numerical': 0.0043541364296081275, 'mean_word_length': 5.211711711711712, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Composition and Seasonal Variation of the Essential Oil from Abies Sachalinensis from Hokkaido, Japan

The composition of the steam-distilled essential oil from the leaves of Abies sachalinensis (F. Schmidt) Mast. cultivated in Hokkaido (Japan) was studied by GC-MS. The seasonal variation in the main volatile constituents was also investigated. Analysis of the essential oil resulted in the identification of 21 compounds with monoterpenes comprising 99.9% of the total. α-Pinene was the most abundant compound, followed by camphene, bornyl acetate, limonene, β-pinene and β-phellandrene. The sesquiterpene content was low, and was mainly represented by β-caryophyllene, α-caryophyllene, and γ-selinene. The essential oil from the leaves, collected at eight different collection periods over more than 5 years, showed significant differences in composition. α-Pinene was the predominant constituent during the collection periods, with a few exceptions. The α-pinene content of the oil was abundant in April-June, and decreased in November-December. Levels of bornyl acetate showed the greatest increase in December, when the temperature was very low. The enantiomeric distribution of α-pinene was suggested to relate to seasonal transformation. (+)-α-Pinene showed a tendency to increase when total precipitation, average temperature, and total duration of sunshine were high.