Functional Properties of Ethyl Acetate-methanol Extract of Commonly Edible Molluscs

ABSTRACT

Marine molluscs are consumed as culinary delicacies and represent a relatively untapped source of natural functional food ingredients. The bioactive potential of ethyl acetate-methanol (C₂H₅OAc/CH₃OH) extract of molluscs Uroteuthis duvaucelii, Amphioctopus marginatus, Crassostrea madrasensis, and Sepiella inermis were demonstrated using different in vitro systems. The C₂H₅OAc/CH₃OH extract of A. marginatus displayed greater 2, 2-diphenyl-1-picryl-hydrazil (IC₉₀ 1.76 mg mL^?1) radical quenching capacity along with potential hydroxymethylglutaryl coenzyme-A reductase (HMGCR)-inhibiting activity (IC₉₀ 1.21 mg mL^?1) and angiotensin converting enzyme-I inhibitory property (ACE-I) (IC₉₀ 0.87 mg mL^?1) compared to those displayed by other molluscs. The organic extract of S. inermis set forth significantly higher pro-inflammatory 5-lipoxygenase inhibitory property (IC₉₀ 1.96 mg mL^?1) along with potential antidiabetic activity as determined by dipeptidyl peptidase-4 (DPP-4) antagonistic activities (IC₉₀ 2.62 mg mL^?1, P < .05). Significant correlations were observed between bioactive properties and electronegative groups of organic extracts of a mollusc. The free radical quenching property of the extracts exhibited a positive correlation towards other bioactivities, implicating the role of antioxidant property of the compounds in the extract to inhibit lifestyle ailments. The present study indicated that S. inermis and A. marginatus could be utilized as functional food ingredients to combat hypertension, hyperlipidemia, and inflammation-related risks.     

Antioxidant Activity of Brown Seaweeds

Antioxidant potential of three brown seaweeds, Anthophycus longifolius, Sargassum plagiophyllum, and Sargassum myriocystum, obtained from the Gulf of Mannar region of India were evaluated utilizing different in vitro systems. Ethyl acetate (EtOAc) fraction of Anthophycus longifolius registered significantly greater hydroxyl radical scavenging ability (IC₅₀ 0.19 mg/mL) and was effective in stabilizing the 2,2′-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid (IC₅₀ 1.23 mg/mL) and 1,1-diphenyl-2-picryl-hydrazil (DPPH) radicals (IC₅₀ 0.48 mg/mL) (p < 0.05). No significant differences in hydrogen peroxide (H₂O₂) scavenging and ferrous ion chelating properties of the EtOAc extracts of the seaweeds were apparent. The utilities of the reverse-phase high-performance liquid chromatography (RP-HPLC) method hyphenated to diode-array detection for analyzing the fingerprints of phenolic constituents in the solvent extracts and fractions of the seaweeds were denoted. High-performance liquid chromatographic analysis indicated the presence of phenolic acids in the solvent extracts of seaweeds. This study demonstrated the potential use of A. longifolius as candidate species to be used as a nutritional food supplement/functional foods to increase the shelf life of food items for human consumption.     

A Comparative Study on Some Functional and Antioxidant Properties of Kilka Meat,Fishmeal, and Stickwater Protein Hydrolysates

This study determined some antioxidative activities and functional properties of hydrolyzed proteins prepared from kilka (Clupeonella sp.) meat (KMH), kilka fishmeal (KFH), and stickwater (SWH). The highest degree of hydrolysis (DH) was 25.02% (p < 0.05) in SWH; however, the difference in DH between KMH and KFH was not significant. KFH had the highest protein content (85.69%) compared with other hydrolysis samples. The Fourier transform infrared spectra of KFH had the highest amide absorption picks (p < 0.05). Solubility at neutral pH was 84.09%, 86.00%, and 93.08% for KMH, KFH, and SWH, respectively. The highest fat absorption capacity was obtained with KFH (204 mg/50 mg). KFH also showed the best foaming properties with 25.66% foaming capacity and proper stability during 60 min (p < 0.05). The highest and lowest whiteness values were obtained in KMH (72.33%) and SWH (36.54%), respectively (p < 0.05). The highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC₅₀ value of 1.99 mg/mL) and 2,2?-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (IC₅₀ value of 2.00 mg/mL) radical scavenging activities were measured at the highest concentrations (40 mg/mL) in KFH (p < 0.05). KFH had the best functional and antioxidant properties, while SWH had a strong ability to inhibit lipid oxidation. Therefore, stickwater from fishmeal production factories is a potential resource for use in developing value-added products instead of being discarded.     

Protein Hydrolysates and Ultrafiltration Fractions Obtained from Krill (Euphausia superba): Nutritional,Functional, Antioxidant,and ACE-Inhibitory Characterization

ABSTRACT

Krill (Euphausia superba) was hydrolyzed by proteolytic enzymes in order to produce multifunctional bioactive peptides, and their functional properties were evaluated. Krill protein hydrolysate (KPH) by pepsin with 4-h hydrolysis showed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and angiotensin I converting enzyme (ACE) inhibitory activities. The solubility and foaming properties of KPH were higher than those of the unhydrolyzed krill protein at a wide range of pHs. KPH was further fractionated based on molecular weight. The 1- to 3-kDa peptide fraction exhibited the highest DPPH scavenging activity (IC₅₀ value of 0.5 mg/mL), oxygen radical absorbance capacity (497.39 ± 4.31 µM TE/mg fraction), 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid cation radical scavenging activity (48.41 ± 0.23 µM TE/mg fraction), and reducing power (110.40 ± 2.07 µM TE/mg fraction). However, the < 1-kDa peptide fraction exhibited a higher ACE inhibitory activity than that of other fractions. The 1- to 3- and < 1-kDa peptide fractions are rich in aromatic and hydrophobic amino acids, respectively.     

Chemical Characterization,Temperature Stability,and Enzymatic Studies on Edible Marine Algae Kappaphycus alvarezii (Doty)

Antioxidant activity of the marine alga Kappaphycus alvarezii was investigated. Methanol, acetone, petroleum ether, aqueous methanol, ethyl acetate, and chloroform extracts (1 mg/mL) of K. alvarezii were tested for their 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. The values were compared with those of Vitamin C and butylated hydroxytoluene (BHT). Extracts showing positive results, when tested for DPPH free radical scavenging, were examined for dose effect, in-vivo hydrogen peroxide (H₂O₂) and hydroxyl radical scavenging assays. All extracts showed dose-dependent DPPH scavenging and significant hydroxyl radical scavenging activities (> 82.6%). The acetone, aqueous methanol, and methanol extracts of K. alvarezii showed the highest scavenging activity. Ethyl acetate extract showed a moderate activity of 62.9%. In the DPPH method, petroleum ether and hexane extracts showed less activity with IC₅₀ values of 118.58 ± 8.94 and 116.25 ± 7.14 μg/mL, respectively. Acetone, methanol, and ethyl acetate extracts exhibited IC₅₀ values of 57.32 ± 1.07, 61.31 ± 0.67, and 79.50 ± 1.59 μg/mL, respectively. K. alvarezii showed higher antioxidant activity in both in vitro and in vivo studies. Proton NMR studies revealed signals in the region 0.5 to 2.0 ppm suggesting the presence of steroidal identity in the extracts.     

大眼金枪鱼头蛋白酶解物1 ku超滤组分的抗氧化活性及其理化性质

研究大眼金枪鱼头蛋白酶解物1 ku超滤组分体外的还原力、自由基清除能力及对衰老小鼠体内抗氧化能力的影响,分析1 ku超滤组分的一般成分、氨基酸组成及分子量分布,为进一步分离纯化金枪鱼头抗氧化肽提供基础。体外结果显示,1 ku超滤组分对羟基自由基、超氧阴离子和DPPH自由基的清除活性随浓度的增加而增强,IC50分别为1.38、0.73与0.93mg/mL,还原力也随浓度的增加而增大,在浓度为12.5 mg/mL时为0.763;体内结果显示,灌胃30 mg/kg的1 ku超滤组分连续42 d,D-半乳糖致衰老小鼠肝组织的超氧化物歧化酶(SOD)活性、肝组织和血清的谷胱甘肽过氧化物酶(GSH-PX)活性显著提高(P<0.05),血清丙二醛(MDA)含量显著降低(P<0.01);理化分析结果显示,1 ku超滤组分(干基计)蛋白质含量为96.40%,脂肪0.11%,灰分4.86%,疏水性氨基酸占氨基酸总量的35.8%,活性组分分子量在1 802~2 519 u和422~922 u。     

Antiparasitic activity of the medicinal plant Dillenia suffruticosa against the marine leech Zeylanicobdella arugamensis (Hirudinea) and its phytochemical composition

Zeylanicobdella arugamensis (Annelida: Hirudinea), a marine parasitic leech, is currently affecting different species of cultured groupers, hybrid groupers, snappers and sea bass in Malaysia. Dillenia suffruticosa (Dilleniaceae), a medicinal plant found in Sabah, has been selected in our experiment to kill the leeches as a natural control method. The leech‐infested hybrid groupers were collected from aquaculture facilities, and the isolated leeches were challenged against methanol extract of D. suffruticosa leaves. The experiment was carried out using various concentrations of the extracts such as 25, 50 and 100 mg/ml. The methanol extract showed significant antiparasitic activity against Z. arugamensis with 100% mortality at a concentration of 100 mg/ml in 14.39 ± 3.75 min., followed by 50 and 25 mg/ml in 32.97 ± 9.29 and 41.77 ± 5.40 min., respectively. The phytochemical composition of the extract was determined using GC‐MS analysis to understand the nature of the principal compounds responsible for its antiparasitic properties. The leaves of D. suffruticosa demonstrated the presence of different bioactive compounds of various natures with varying percentages. Thus, it could be revealed that the methanol extract of D. suffruticosa mainly contains vital phytochemical compounds and showed an effective antiparasitic activity against the harmful leeches of hybrid groupers.     

Utilization of Shrimp By-Products by Bioconversion with Medical Fungi for Angiotensin I-Converting Enzyme Inhibitor and Antioxidant

ABSTRACT

A liquid fermentation process to bioconvert shrimp by-products was developed with two species of fungi, Boletus edulis and Suillus bovinus. Angiotensin I-converting enzyme (ACE) inhibitory, antioxidant activities of bioconverted products and the deodorization effect of fungal bioconversion were determined. Two species of fungi could grow quickly in shrimp by-products medium and deodorize shrimp by-products. Bioconverted products had higher ACE inhibitory and antioxidant activities than control medium. Water extracts without crude polysaccharides from mycelia of B. edulis had the highest ACE inhibitory activity (IC₅₀ = 0.084 ± 0.011 mg/mL). Crude exopolysaccharides of B. edulis had higher antioxidant activity. Bioconversion with the fungus was proven to be a novel, practicable way to recycle shrimp by-products.     

Lessons on broodstock maintenance,spawning, larval rearing and juvenile production of marine gastropods of ornamental value

Research on marine gastropod breeding in India is in its infancy and scanty literature is only available. To fill the lacunae, marine gastropods of three ornamentally valued and conservation important groups such as Cyprids, Strombids and Muricids were held under captivity and studied for their broodstock maintenance, spawning behaviour, larval rearing and metamorphosis into juveniles at the Shellfish Hatchery of Central Marine Fisheries Research Institute, Tuticorin. Valuable information on the focal themes of the article was obtained for Strombids and Muricids leading to the successful life cycle closing for Lambis lambis and Chicoreus virgineus are reported earlier. In the present study, experiments were conducted on aspects such as post‐metamorphosed juvenile rearing up to 76 days post hatch for L. lambis, spawning, larval development and life cycle closing and reasonable level of juvenile production (8.8%) for Chicoreus ramosus. In addition, the primary observations on the captive breeding of Cypraea tigris with reference to its egg mass, brooding habit and early development is reported. However, while studying these groups few unanswered questions and bottle necks in their breeding nature, larval rearing and metamorphosis arose. The following account details the experiments conducted and results obtained in each of the focal themes of the paper and the constraints faced.     

Efficacy of a Fructus mume Extract Combination with Stable Chlorine in Preventing Bacterial Contamination in Frozen Mackerel (Scomber japonicus) Fillets

ABSTRACT

A combination composed of Fructus mume extract and stable chlorine dioxide was investigated for its antibacterial activity, mechanism of action, and its application against Escherichia coli and Staphylococcus aureus in mackerel (Scomber japonicus) fillets. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against E. coli and S. aureus ranged from 0.9–1.2 and 1.3–1.6 mg/mL for F. mume extract and 0.004–0.006 and 0.007–0.010 mg/mL for stable chlorine dioxide, respectively. We observed a mechanism of action against E. coli that involved a pore-formation role that led to cell membrane damage. In the case of S. aureus, the mechanism of action is believed to be mediated by the combination’s activity as a metabolite disrupting agent. Here, the amount of bacteria was greatly reduced in mackerel fillets treated with the combination. Moreover, the flavor and texture properties of fillets were not significantly affected by this treatment (p < 0.05). These findings suggested that the combination has promise in being used as an additive to a broader class of foodstuffs.     

Antiviral activities of Clinacanthus nutans (Burm.f.) Lindau extract against Cyprinid herpesvirus 3 in koi (Cyprinus carpio koi)

Cyprinid herpesvirus 3 (CyHV‐3) or koi herpesvirus (KHV) is a virulent viral infection in common carp and koi. The disease has caused global epizootic and economic loss in fish aquaculture and in the wild. Clinacanthus nutans (Burm. f.) Lindau is a well‐known medicinal plant used in Thai traditional medicine. Virucidal effects of the plant extract against human herpes simplex virus have been reported. In this study, C. nutans crude extract was tested for antiviral activities against CyHV‐3 in koi carp. Results showed effective antiviral activity against CyHV‐3 pre‐ and post‐infection. The 50% lethal concentration (LC₅₀) of extract was higher than 5 mg/ml. The 50% effective dose (ED₅₀) was 0.99 mg/ml, 0.78 mg/ml, 0.75 mg/ml and 0.71 mg/ml at 1, 2, 3 and 4 hr pre‐infection, respectively. The ED₅₀ from post‐infection tests was 2.05 mg/ml and 2.34 mg/ml at 0 and 24 hr, respectively. These results demonstrated that crude extract expressed antiviral activity against CyHV‐3 and can be applied as a therapeutic agent in common carp and koi aquaculture.     

胰蛋白酶酶解制备孔鳐软骨蛋白寡肽及其抗氧化活性

以孔鳐软骨为材料,采用盐酸胍抽提、丙酮分级沉淀,制备孔鳐软骨蛋白;以DPPH·和HO·清除活性为导向,采用胰蛋白酶酶解、膜超滤、DEAE-52阴离子交换层析、Sephadex G-15凝胶层析和反相高效液相色谱(RP-HPLC)等技术,制备抗氧化肽,并对其活性进行系统评价。结果显示,孔鳐软骨蛋白经胰蛋白酶酶解和分离纯化得到2个抗氧化肽RCPE-A和RCPE-B,经氨基酸序列分析确定其序列分别为Gly-Glu-Glu-Gly-Pro-Arg-Gly (GEEGPRG)和Gly-Glu-Glu-Gly-Thr-Met-Gly-Leu (GEEGTMGL),质谱(ESI-MS)测定其分子量分别为700.71和792.87 u。体外自由基清除实验结果显示,RCPE-A与RCPE-B对DPPH·(EC₅₀ 2.94和1.16 mg/mL)、HO·(EC₅₀ 0.34和0.54 mg/mL)、ABTS⁺·(EC₅₀ 0.34和0.10 mg/mL)和O₂^-·(EC₅₀ 0.11和0.03 mg/mL)具有良好的清除作用,RCPE-A与RCPE-B亦显示出较强的脂质过氧化抑制作用。研究表明,孔鳐软骨蛋白酶解物及制备多肽可用于抗氧化相关的功能食品开发,也可以用作抗氧化剂延长相关产品的货架期。     

Assessment of Aquatic Aeromonas spp. Isolates' Susceptibility to Cinnamaldehyde,Vanillin, and Crude Kigelia africana Fruit Extracts

Aeromonas spp. are primary and opportunistic fish pathogens that are responsible for severe economic losses in aquaculture, and are exacerbated by their increasing incidence of antimicrobial resistance. Phytochemicals are being explored as alternatives to conventional antimicrobial agents since they have destressing, growth‐promoting, immune‐stimulating, and antimicrobial properties. The susceptibility of 93 aquatic Aeromonas spp. and six Plesiomonas shigelloides isolates (from cultured catfish, koi carp, tilapia, and seawater) to three phytochemicals, viz.: cinnamaldehyde (10–1250 µg/mL), vanillin (5–250 µg/mL), and crude Kigelia africana fruit extracts (4–10 mg/mL ethyl acetate, dichloromethane, methanol, and hexane) were assessed using the disk diffusion assay and compared to ampicillin and tetracycline, using activity indices. No zones of inhibition were obtained with 10 µg/mL of cinnamaldehyde, or with 5–250 µg/mL of vanillin. However, varying degrees of inhibition were observed with higher concentrations of cinnamaldehyde, as well as with the K. africana methanol extract. Cinnamaldehyde (≥500 µg/mL) and the K. africana methanol extract displayed better antimicrobial activity against study isolates in comparison to vanillin and ampicillin. They appear to be promising and sustainable phytochemicals that might be useful as alternatives to the antimicrobial agents currently in use in aquaculture.     

Inhibitory activities of the edible brown alga <Emphasis Type="Italic">Laminaria japonica</Emphasis> on glucose-mediated protein damage and rat lens aldose reductase

Increased aldose reductase (AR)-related polyol pathway activity and the subsequent formation of advanced glycation end-products (AGEs) have been implicated in the onset of diabetic complications. We have evaluated the inhibitory effects of the methanolic extract and its fractions of Laminaria japonica on rat lens AR (RLAR) and AGE formation. The CH₂Cl₂ fraction was separated by high-performance liquid chromatography to yield active porphyrin derivatives, including pheophorbide a (1) and pheophytin a (2), which were assayed for their anti-diabetic complications and yield. Compound 1 exhibited potent inhibitory activities against both AGE formation and RLAR, with respective half-maximal inhibitory concentration (IC₅₀) values of 49.4 and 12.3 μM. Conversely, compound 2 was found to be active against AGE formation, with an IC₅₀ of 228.7 μM. For further elucidation of the structure–inhibitory activity relationship of the porphyrin derivatives, the inhibitory activities of four commercially available porphyrin derivatives on AGE formation and RLAR were measured. The presence of a carboxyl group and the absence of a phytyl group at the C-17² position of the porphyrin were found to contribute to the inhibitory effects towards both AGE formation and RLAR. These results suggest that the L. japonica and its porphyrin derivatives may represent a potential functional food resource for further prevention of diabetic complications.     

Antioxidant and anti‐inflammatory activities of Pinus radiata bark extract in salmonid cell lines

A fish meal supply shortage is limiting aquaculture development. Currently, plant‐based proteins, such as soya bean meal, are being used as an alternative protein source, despite that such a diet can adversely affect fish, such as by inducing an inflammatory response. A possible solution is to include dietary additives in farm diets to counteract negative effects. One such solution originates from pine bark extracts, which present bioactive properties. In this study, the antioxidant and anti‐inflammatory properties of Pinus radiata bark extracts were evaluated for the first time in a salmonid cell line. This extract chemically demonstrated antioxidant activity through 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH = 58.4 ± 1.1%) and ferric ion reducing antioxidant power (FRAP = 575 ± 17 mgEqFe(II)·g extract^?1) assays. Additionally, the extract showed high flavonoid and phenolic compound contents. Up to 100 mg mL^?1, the P. radiata extract showed no cytotoxicity in the CHSE‐214 salmonid embryo cell line. Moreover, the antioxidant activity of the extract (50 μg mL^?1) was evaluated by a dichlorofluorescein (DCFH) assay in the SHK‐1 salmon cell line challenged with an oxidant stimulus (H₂O₂), showing 58.9% activity. The extract also protected DNA from oxidative damage, as observed through a comet assay. When assessing anti‐inflammatory properties in an in vitro inflammation model, the extract significantly reduced the relative expression of the pro‐inflammatory cytokines interleukin‐1β (IL‐1β), tumour necrosis factor‐α (TNF‐α) and interleukin‐8 (IL‐8) and of the inducible cyclooxygenase‐2 (COX‐2) enzyme. These results suggest a potential application of P. radiata bark extract in functional foods in aquaculture.     

Improving estimates of richness,habitat associations,and assemblage characteristics of freshwater gastropods

1. Freshwater gastropods are imperilled globally and are among North America's most vulnerable major animal groups. Habitat loss, invasive species, and inadequate information about species distributions and assemblages all impair efforts to conserve freshwater gastropods. Conservation efforts are also impaired by difficulty obtaining and using distributional data for snails and other inconspicuous organisms, which are required to assess habitat associations.
2. A gastropod‐specific sampling protocol was developed and used to survey 110 sites from 24 sub‐basins in two major river basins of the Intermountain West, USA. Habitat associations of individual taxa and groups of taxa that co‐occurred together more frequently than expected by chance were also examined.
3. Using the gastropod‐specific sampling protocol, snails were found at most sites, even in regions where general macroinvertebrate sampling did not detect snails. Thus, these results show that general macroinvertebrate surveys do not accurately reflect the diversity of freshwater gastropods. Although snails of the same family are typically expected to live in the same habitats, this study found that in most cases, within a gastropod family, taxa exhibited unique habitat associations because they co‐occurred more frequently with taxa from different gastropod families. Five genera or sub‐genera were associated with specific mesohabitat or substrate types while two groups of co‐occurring taxa were associated with specific land classes or landform types.
4. For diverse, inconspicuous taxa such as freshwater gastropods, qualitative, class‐specific sampling methods, and analyses of habitat associations based on co‐occurring taxa, rather than relatedness, should facilitate conservation efforts.

     

Optimized Extraction,Preliminary Characterization and Evaluation of the in Vitro Anticancer Activity of Phlorotannin-Rich Fraction from the Brown Seaweed,Cystoseira sedoides

Brown seaweeds produce useful bioactive substances with high cosmetic and pharmacological values due to the presence of antioxidant derivatives, mainly phlorotannins (PHT), which are of particular interest. A central composite rotatable design (CCRD) with three variables (extraction time, dry material-to-solvent ratio and ethanol concentration) and two responses was performed to optimize the microwave-assisted extraction (MAE) of phlorotannins from Cystoseira sedoides using response surface methodology (RSM). Results showed that the independent variables significantly affected both phlorotannin content and the scavenging capacity. The optimum operating conditions were extraction time, 101.74 sec; dry material-to-solvent ratio, 1:10 g/mL; and ethanol extraction, 50%. Under these conditions, the predicted values of PHT content and radical scavenging activity-IC50 were close to the observed values and were 383.887 µg PGE/g Dm and 18.353 µg/mL, respectively. Characterization of the phlorotannin-rich fraction was conducted by high-performance liquid chromatography and Fourier transform infrared spectroscopy. The evaluation of the anticancer activity against MCF-7 breast cancer cell line showed a potent activity to trigger apoptotic death in more than a half of the MCF-7 cells, with an estimated IC50 value of 78 μg/mL. In addition, this fraction induced a notable growth regression effect on 3D spheroids model in a concentration-dependent manner, with a growth rate of about 1.17, at 200 µg/mL.

Abbreviations: CCRD: Central composite rotatable design; Dm: Dry material; DMBA: 2,4-dimethoxy benzaldehyde; DMSO: Dimethyl sulfoxide; DPPH: 1,1-diphenyl-2-picrylhydrazyl; EDTA: Ethylene diamine tetraacetic acid; FBS: Fetal bovine serum; FT-IR: Fourier transform infrared; HPLC: High-performance liquid chromatography; IC₅₀: Half-maximal inhibitory concentration; MAE: Microwave-assisted extraction; Min: minutes; PBS: Phosphate buffered saline; PGE: Phloroglucinol equivalent; PHT: Phlorotannins; PHT-SED: phlorotannins derived from Cystoseira sedoides; PI: Propidium iodide; RSA: Radical scavenging activity; RSM: Response surface methodology; Sec: seconds     

Biological Activities of Freshwater Algae,Spirogyra singularis Nordstedt

Spirogyra is commonly found as accessible algae in freshwater areas all over the world. Some medical uses have been reported from this genus. Biological activities of Spirogyra singularis were investigated employing eight in vitro assays. The extract showed different antioxidant activity. IC₅₀ for DPPH radical-scavenging was 4.71 ± 0.11 μg mL^?1. The extract showed very strong nitric oxide-scavenging activity with IC₅₀ = 77.3 ± 2.07 μg mL^?1, but its Fe²⁺ chelating ability was weak. The extract also exhibited high antioxidant activity in hemoglobin-induced linoleic acid peroxidation tests and scavenging of hydrogen peroxide. The extract also showed good antihemolytic activity. The total amount of phenolic content in the extract was determined as gallic acid equivalents, and total flavonoid content was calculated as quercetin equivalents. Biological activities may be attributed, at least in part, to the presence of phenol and flavonoid contents in the extract.     

Recovery of Aliphatic Fatty Acids from Red Seaweed Champia parvula (C. Agardh) and Its Antifungal Action

The aim of the present study was to evaluate the antifungal activity of seaweed Champia parvula and identification of active compounds for this action. In this regard, C. parvula crude extracts were obtained from n-hexane, ethyl acetate, chloroform, methanol, and water used to study the antifungal action. Results showed that methanolic extract had potent action against C. albicans, C. tropicalis, T. mentagrophytes, and A.flavus, with the highest inhibition of 16.7 mm found against C. tropicalis. Minimum inhibition concentration at 12.5 and minimum fungal concentration at 25 μg/mL were found in the methanolic extract. Therefore, to identify the bioactive compound for this antifungal action in the methanolic extract, thin-layer chromatography (TLC) and reverse-phase high-performance liquid chromatography (RP-HPLC) were used. The RP-HPLC had three peaks with retention times at 3.30, 3.86, and 4.73 min, showing the presence of ester fatty acid compound. Further, these compounds were characterized by nuclear magnetic resonance (NMR), gas chromatography (GC), and liquid chromatography-mass spectrometry (LC-MS), which showed the presence of long-chain aliphatic fatty acid like eicosanoic acid with formation of oct-1-en-3-ol compounds attached.     

Recovery of Bioactive Peptides and Omega-3 Fatty Acids-Containing Phospholipids from Squid Processing By-Product Hydrolysate

ABSTRACT

The present study examined whether bioactive peptides and omega-3 fatty acids-containing phopholipids could be recovered from squid processing by-product (SPB) hydrolysate. The hydrolysate was produced at 55°C for varying times with endogenous proteases and centrifuged to yield peptides-containing supernatant and phospholipids-containing precipitate. The supernatant showed angiotensin I-converting enzyme (ACE) inhibitory activity with half maximal inhibitory concentration (IC₅₀) values decreasing with hydrolysis time from 2.11 mg (0 h) to 1.71 mg (1 h), 1.38 mg (1.5 h), and 1.34 mg (2 h). Two-hour squid hydrolysate was further fractionated to isolate the most active fraction whose molecular weight was found to be below 10 kDa with IC₅₀ of 0.32 mg. The phospholipids-containing precipitate (45.6 g/100 g oil) was analyzed for a fatty acid profile, with the levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) being 16.86 and 29.24 g/100 g oil, respectively. The ACE inhibition by hydrolysate peptides and omega-3 fatty acid recovery support the nutraceutical potential of the SPB hydrolysate.