Synthesis, Odour Characteristics, and Antimicrobial Activity of Optically Active Dodecen-4-olides and Their Cyclopropanated Derivatives

Aug 27, 2026

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Four optically active dodecen-4-olides (1a–d) with carbon–carbon double bonds at distinct positions and their cyclopropanated derivatives (2a–d) were synthesized and evaluated by odour profiling. Compounds 1a–d and 2a–d displayed lactone-like nuances, dominated by strong top notes and oily middle notes, with double-bond position strongly shaping the odour. Cyclopropanation markedly altered profiles: in particular, conversion of 1a’s double bond shifted fruity to green and cyclopropanation of 1b shifted green to fruity. Antimicrobial testing against E. coli and S. aureus showed (S)-1b activity against S. aureus only.

LanguageEnglish

CategoryHealthcare

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Pages21

Reading Time53 min

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Abstract

Keywords

1 Introduction

2 Experimental Procedures

2.1 Materials

Synthesis, Odour Characteristics, and Antimicrobial Activity of Optically Active Dodecen-4-olides and Their Cyclopropanated Derivatives Yasutaka Shimotori 1* , Hinata Sugimoto2 , Takayuki Honda 2 , Tetsuo Miyakoshi2 , Hiroyuki Masuda3 , Takanori Shima3 , Shiori Kitago3 , Mika Iwamoto4 , Daisuke Asai5 , and Taisei Kanamoto5 1 Graduate School of Engineering, Kitami Institute of Technology, Kitami, JAPAN 2 Graduate School of Science and Technology, Meiji University, Kawasaki, JAPAN 3 Research and Development Laboratory, Nagaoka Co., Ltd, Ibaraki, JAPAN 4 Flavor Institute R&D Osaka Laboratory, Nagaoka Co., Ltd, Osaka, JAPAN 5 Laboratory of Microbiology, Showa Pharmaceutical University, Machida, JAPAN Abstract: Four optically active dodecen-4-olides (1a–d) with carbon–carbon double bonds at different positions and their cyclopropanated derivatives (2a–d) were synthesized, and the odour characteristics of the racemic and optically active compounds were evaluated. Compounds 1a– d and 2a–d exhibited typical lactone-like nuances, characterized by strong top notes and oily middle notes. The position of the carbon–carbon double bond had a significant effect on the odour profile. All 1a–d compounds exhibited different odour characteristics: 1a showed fruity notes, 1b and 1c exhibited green and fruity notes, and 1d exhibited green and floral notes. Cyclopropanation substantially altered these characteristics. As a result, the odour characteristics of compounds 2, where the carbon–carbon double bonds were converted to cyclopropane rings, differed significantly from those of compounds 1. Conversion of the double bond in 1a to a cyclopropane ring changed the fruity note to green note, while cyclopropanation of 1b changed the green note to fruity. The antimicrobial activities of 1 and 2 against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were also investigated. Only compound (S)-1b exhibited antimicrobial activity against S. aureus. Keywords: dodecen-4-olide, carbon-carbon double bond, cyclopropane ring, odour characteristics, antimicrobial activity 1 Introduction Lactones are important flavour compounds found in several food items, including fruits1, 2), breads3, 4), meats5, 6), beverages7, 8) and dairy products9, 10) . They are widely used in the food and fragrance industries because of their fruity, coconut, buttery, sweet and nutty odour characteristics11, 12) . For example,(Z)-7-decen-4-olide is found in essential oils13), strawberries14), peaches15), and nectarines16), and serves as an important flavouring compound because of its sweet, creamy, and floral notes17) . The odour properties are significantly affected by the absolute configuration, number of carbons in the side chain18, 19), and position of the carbon–carbon double bond20) . In a previous study, we synthesized optically active (Z)-7-decen-4-olide derivatives and investigated their odour properties21) . (Z)-7-decen-4-olide, (Z)-8-decen-4-olide, Fig. 1 Structures of dodecen-4-olides (1) and its cyclopropanated derivatives (2) . and 9-decen-4-olide exhibited fruity, milky, and peachy notes, respectively, indicating that the position of the carbon– carbon double bond plays a crucial role in determining odour characteristics. Undecan-4-olide and dodecan-4-olide possess sweet, milky, fatty, and creamy notes22, 23) . Interestingly, introducing a double bond into the lactone side chain resulted in a completely different odour; (Z)-7-, (Z)-8-undecen-4-olide, and (Z)-7-dodecen-4-olide exhibited green notes. It is reported that conversion of the carbon–carbon double bond to a cyclopropane ring significantly changed the odour properties24, 25) . For example,(±)-1b had a strong green note, whereas (±)-2b had a strong fruity note in this study. Lactones also exhibit a wide range of biological activities, including anti-inflammatory26), analgesic27), antitumor28), and antibacterial29) activities. In our previous study, the antimicrobial activ

FAQs

What compounds were synthesized in the study?

Four optically active dodecen-4-olides (1a–d) with carbon–carbon double bonds at different positions and their cyclopropanated derivatives (2a–d) were synthesized and studied.

How does the carbon–carbon double bond position affect odour characteristics?

The position of the carbon–carbon double bond significantly changes the odour profile, producing distinct notes across compounds 1a–d (e.g., fruity, green and fruity, or green and floral).

What effect does cyclopropanation have on odour and antimicrobial activity?

Cyclopropanation substantially alters odour characteristics by changing the dominant notes compared with the corresponding alkenes. For antimicrobial activity against E. coli and S. aureus, only compound (S)-1b showed activity against S. aureus.

Aug 27, 2026

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