Antioxidative oxygenated terpenoids with bioactivities against pro-inflammatory inducible enzymes from Indian squid, Uroteuthis (Photololigo) duvaucelii

Abstract

Cephalopod squid, Uroteuthis (Photololigo) duvaucelii is consumed as culinary delicacy along the southwest part of Asian continent. Ethyl acetate:methanol extract of U. duvaucelii was chromatographically fractionated to yield C₁₉ furano-norditerpenoid (1) along with irregular C₁₅ sesquiterpenoid (2) and C₂₀ diterpenoid compounds (3). In vitro anti-inflammatory and antioxidant analyses were utilised to evaluate their bio-potentials. The C₁₉ furano-norditerpenoid was reported for significantly effective 2,2-diphenyl-1-picrylhydrazyl radical inhibition (IC₅₀ 0.60 mg/mL) than other compounds and α-tocopherol (IC₅₀ ≥ 0.64 mg/mL). The 2,2’-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid inhibition and ferrous ion chelating potentials were higher for compounds 1 and 2 (IC₅₀ ∼ 0.69 and ∼0.84 mg/mL, respectively) compared to α-tocopherol (IC₅₀ 0.76–0.95 mg/mL). The studied compounds displayed comparable inhibitory activities with synthetic ibuprofen against pro-inflammatory inducible 5-lipoxygenase (IC₅₀ ∼ 0.92 mg/mL). The lower hydrophobicity and steric variables were directly correlated with their antioxidative and anti-inflammatory properties. The studied compounds could be utilised as natural antioxidants and anti-inflammatory functional food ingredients.

Keywords:

• Uroteuthis duvaucelii
• cephalopod squid
• oxygenated terpenoids
• antioxidant and anti-inflammatory
• functional food

Acknowledgements

The authors are thankful to the Ministry of Science and Technology of Department of Biotechnology, Government of India, New Delhi for funding (grant number BT/PR15757/AAQ/3/757/2015). . The authors thank the Director, Central Marine Fisheries Research Institute for guidance and support. Thanks are due to the Head, Marine Biotechnology Division, Central Marine Fisheries Research Institute for facilitating the research activity. The authors are thankful to Dr. C. Baby, Technical Officer, Sophisticated Analytical Instruments Facility of Indian Institute of Technology, Madras for nuclear magnetic spectral analysis of the isolated metabolites.

Disclosure statement

No potential conflict of interest was reported by the authors.