A hybrid RSM-ANN-GA approach on optimisation of extraction conditions for bioactive component-rich laver (Porphyra dentata) extract.

This research established the optimal conditions for infusion extraction (IE) and ultrasound-assisted extraction (UAE) of bioactive components from laver (Porphyra dentata) using response surface methodology (RSM) and artificial neural network coupled with genetic algorithm (RSM-ANN-GA). The variables, temperatures (60, 80, and 100 ℃) and times (10, 15, and 20 min) were designed to optimise total phenolic, total flavonoid, total amino acid, a* value, and R-phycoerythrin content of laver extract. The optimised condition for IE and UAE was achieved at 60 ℃ for 18.08 min and 80.66℃ for 14.76 min in RSM while showing 60 ℃ for 19 min and 80℃ for 15 min in the RSM-ANN-GA mode, respectively. Results revealed that RSM-ANN-GA provided better predictability and greater accuracy than the RSM model and laver extract from UAE gave the higher values of responses compared to those from IE. These findings highlight the high-efficient extraction method along with better statistical approach.

Four New Dicaffeoylquinic Acid Derivatives from Glasswort (Salicornia herbacea L.) and Their Antioxidative Activity.

Four new dicaffeoylquinic acid derivatives and two known 3-caffeoylquinic acid derivatives were isolated from methanol extracts using the aerial parts of Salicornia herbacea. The four new dicaffeoylquinic acid derivatives were established as 3-caffeoyl-5-dihydrocaffeoylquinic acid, 3-caffeoyl-5-dihydrocaffeoylquinic acid methyl ester, 3-caffeoyl-4-dihydrocaffeoylquinic acid methyl ester, and 3,5-di-dihydrocaffeoylquinic acid methyl ester. Their chemical structures were determined by nuclear magnetic resonance and electrospray ionization-mass spectroscopy (LC-ESI-MS). In addition, the presence of dicaffeoylquinic acid derivatives in this plant was reconfirmed by LC-ESI-MS/MS analysis. The isolated compounds strongly scavenged 1,1-diphenyl-2-picrylhydrazyl radicals and inhibited cholesteryl ester hydroperoxide formation during rat blood plasma oxidation induced by copper ions. These results indicate that the caffeoylquinic acid derivatives may partially contribute to the antioxidative effect of S. herbacea.

Antimicrobial activity of the synthesized non-allergenic urushiol derivatives.

Synthesized urushiol derivatives possessing different carbon atomic length in the alkyl side chain inhibited the growth of food spoilage and pathogenic microorganisms. Particularly, non-allergenic 3-pentylcatechol showed a broad antimicrobial spectrum on an agar plate. Most food spoilage and pathogenic microorganisms were sensitive to urushiol derivatives in the liquid culture. The morphologies of the microorganisms were changed after treatment of 3-pentylcatechol.

Dietary flounder skin improves growth performance, body composition, and stress recovery in the juvenile black rockfish (Sebastes schlegeli).

This study investigated the relationship between flounder skin meal (FSM) and vitamin C in mediating collagen biosynthesis. Based on the vitamin C requirements (150 mg/kg) of the black rockfish (mean body weight 10.05 ± 0.44 g), a vitamin C level of 400 mg/kg was selected, and 0, 5, 10, or 20% of the casein (purified proteins) in the diet was replaced with FSM. The feeding study was conducted for 8 weeks by using 4 experimental groups. The FSM supplementation resulted in improvement in growth performance, decrease of body lipids. Furthermore, it elevated the HDL-cholesterol levels and total protein content, reduced blood lipids, and led to rapid recovery in stress, which confirm the functionality of FSM with high collagen content.

Biochemical characteristics of four marine fish skins in Korea.

In this study, we investigated the biochemical characteristics of the fish skins of four industrial species: olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), sea bass (Lateolabrax maculatus) and red sea bream (Pagrus major). There is high domestic demand in Korea for farming of these fish for human consumption. Crude protein contents in the skin of these fish ranged from 73% to 94% by dry weight; this was in part due to a high content of the structural protein, collagen. Among the four species, olive flounder had the thickest dermal and epidermal layers in the dorsal skin. This species was also associated with the highest extraction ratio of acid-soluble collagen. We also examined whether fish skin could be a cost-effective alternative to current fish meal sources. Our analysis indicates that, when supplemented with additional fish oils and essential amino acids, fish skin is a viable alternative for fish meal formulations.

Acyclo-retinoic acid induces apoptosis in human prostate cancer cells.

Acyclo-retinoic acid, a novel acyclic analogue of all-trans-retinoic acid, has been previously isolated as one of the in vitro oxidation products of lycopene. The effect of acyclo-retinoic acid on the growth of human prostate cancer cells was compared with those of the four retinoids: all-trans-retinoic acid, geranylgeranoic acid, 9-cis-retinoic acid and N-(4-hydroxyphenyl)retinamide. When prostate cancer cells, PC-3, DU 145 and LNCaP, were cultured in a retinoid-supplemented medium, acyclo-retinoic acid remarkably reduced the viability of the cells except for LNCaP. This effect was significantly higher than that of geranylgeranoic acid, all-trans-retinoic acid and 9-cis-retinoic acid, but was comparable to that of N-(4-hydroxyphenyl)retinamide. DNA fragmentations of nuclei in PC-3 and DU 145 cells treated with acyclo-retinoic acid were detected by in situ TUNEL assay. Furthermore, an apoptotic DNA ladder was observed in PC-3 cells. These results showed that acyclo-retinoic acid reduced cell viability by inducing apoptosis in human prostate cancer cells.