Chemical Profile, Antioxidant Activity and α-Glucosidase Inhibition of Sea Grape Caulerpa lentillifera Collected from Different Sites in Thailand

Abstract

Caulerpa lentillifera (sea grapes) stands out for its nutritional profile and associated health advantages. Seaweeds, including sea grapes, exhibit diverse chemical compositions that are influenced by environmental conditions. This study aimed to compare the chemical composition, metabolite content, antioxidant activity and α-glucosidase inhibition of sea grapes collected at different sites (Phetchaburi and Trang) and at different times during the month of January, April, and July 2022. Both collection times and sites have influenced all assessed parameters. The sea grapes collected from Trang had a significantly higher amount of metabolite, antioxidant activity and α-glucosidase inhibitory activity than those from Phetchaburi at p < 0.001. The highest amount of phenolic compound (93.76 ± 2.39 mg GAE/g extract) and reducing power (EC50 = 25.86 ± 0.20 mg/mL) occurred in sea grapes in April month, while those collected in January and April had high DPPH and ABTS radical scavenging (EC50 < 7.50 mg/mL). The highest inhibitory activity against α-glucosidase (EC50 = 19.27 ± 0.40 mg/mL) was found in the sea grapes collected in January. The LC-QTOF MS/MS result of sea grape extract indicated similar compounds in amino acids, fatty acids, lipids, nucleic acids, carboxylic acids, cyanogenic glucosides, steroids, terpenoids and vitamins. The disparity in phenolic profiles between Phetchaburi (9) and Trang (14) sea grapes was related to higher phenolic compound and flavonoid contents, coupled with antioxidant properties in Trang. These findings supported the possible use of sea grapes from Trang as a reservoir of bioactive compounds. HIGHLIGHTS Chemical profile and content, antioxidant and α-glucosidase inhibition of sea grapes was analyzed Collection times and sites affected all measured parameters of sea grapes extract Sea grapes from Trang exhibited higher all measured parameters than Phetchaburi A novel chemical profiling of sea grapes was displayed via LC-QTOF MS/MS analysis GRAPHICAL ABSTRACT