Bioactive compounds and antioxidant activities of the Korean lotus leaf (Nelumbo nucifera) condiment: volatile and nonvolatile metabolite profiling during fermentation

Recent studies have shown that lotus (Nelumbo nucifera) leaf has various pharmacological effects. However, there have been no scientific investigations into these leaves as a fermented crude liquid. This study compared the in vitro antioxidant capacity of lotus leaf‐fermented broth (LLFB) with that of 57° Brix sugar broth (SB) as a control over a period of 6 months based on 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity, ferric ion reducing power, superoxide dismutase‐like activity, tyrosinase inhibition and nitrite scavenging activity. The dominant species during fermentation process were Leuconostoc lactis and Saccharomyces cerevisiae for LLFB. A total of thirty‐six metabolites such as alkaloids, fatty acids, organic acids, phenolics, sugar and sugar derivatives, ethyl esters and monoterpenoids differed between SB and LLFB using gas chromatography–mass spectrometry. Meanwhile, nine volatile compounds in LLFB contributed pleasant, slightly sweetish and fruity odour of condiment and sensory evaluation score of 4.06 ± 1.52 in the proportion of 1:9 LLFB/water.     

Purification and Characterization of Aporphine Alkaloids from Leaves of Nelumbo nucifera Gaertn and Their Effects on Glucose Consumption in 3T3-L1 Adipocytes

Aporphine alkaloids from the leaves of Nelumbo nucifera Gaertn are substances of great interest because of their important pharmacological activities, particularly anti-diabetic, anti-obesity, anti-hyperlipidemic, anti-oxidant, and anti-HIV’s activities. In order to produce large amounts of pure alkaloid for research purposes, a novel method using high-speed counter-current chromatography (HSCCC) was developed. Without any initial cleanup steps, four main aporphine alkaloids, including 2-hydroxy-1-methoxyaporphine, pronuciferine, nuciferine and roemerine were successfully purified from the crude extract by HSCCC in one step. The separation was performed with a simple two-phase solvent system composed of n-hexane-ethyl acetate-methanol-acetonitrile-water (5:3:3:2.5:5, v/v/v/v/v). In each operation, 100 mg crude extracts was separated and yielded 6.3 mg of 2-hydroxy-1-methoxyaporphine (95.1% purity), 1.1 mg of pronuciferine (96.8% purity), 8.5 mg of nuciferine (98.9% purity), and 2.7 mg of roemerine (97.4%) respectively. The chemical structure of four aporphine alkaloids are identified by means of electrospray ionization MS (ESI-MS) and nuclear magnetic resonance (NMR) analysis. Moreover, the effects of four separated aporphine alkaloids on insulin-stimulated glucose consumption were examined in 3T3-L1 adipocytes. The results showed that 2-hydroxy-1-methoxyaporphine and pronuciferine increased the glucose consumption significantly as rosiglitazone did.     

Variation of phenolic content in coconut oil extracted by two conventional methods

Phenolic compounds present in the nonsaponifiable fraction of coconut oil were analysed by high‐performance liquid chromatography with florescence detection. Mass spectra of the phenolic compounds were also obtained separately by LC–MS to confirm the presence of the phenolic compounds. Caffeic acid, p‐coumaric acid, ferulic acid and (+/?) catechin were observed in coconut oil. Phenolic acid fraction of the coconut oil prepared by boiling coconut milk (traditional coconut oil) was more complex compared with that of coconut oil prepared by pressing copra (commercial coconut oil). Total phenol content of traditional coconut oil was nearly seven times higher than that of commercial coconut oil (618 ± 46 vs. 91 ± 11 mg kg^?1), suggesting that the phenol content varies with the extraction method.     

超声辅助提取-高效液相色谱法测定荷叶中的生物碱

采用超声提取法提取荷叶中的O-去甲荷叶碱、N-去甲荷叶碱、荷叶碱和莲碱4种主要的生物碱,建立HPLC分析方法进行评价,为荷叶及相关产品的质量控制提供参考。选用Welch Materials C18色谱柱(250 mm×4.6 mm,5μm),以乙腈-水(含0.1%三乙胺)为流动相进行梯度洗脱,实现了O-去甲荷叶碱、N-去甲荷叶碱、荷叶碱和莲碱4种生物碱的同时基线分离。在0.1～50μg/mL范围内,O-去甲荷叶碱(R=0.999 8)、N-去甲荷叶碱(R=0.999 9)、荷叶碱(R=0.999 8)和莲碱(R=0.999 8)具有良好的线性关系,检出限分别为1.87、2.22、2.34和1.88 ng/mL(S/N=3∶1)。     

Antioxidant activity of bovine and porcine meat treated with extracts from edible lotus (Nelumbo nucifera) rhizome knot and leaf

Lotus (Nelumbo nucifera) is an extensively cultivated vegetable in eastern Asia, particularly in China. Both lotus rhizome knot (LRK) and lotus leaf (LL) are waste products of the lotus industry. Extracts from LRK and LL are proposed as antioxidants for meat. Porcine and bovine ground meat samples were subjected to three treatments: CONTROL (with no additives), LRK (lotus rhizomes knot extract 3% w/w), and LL (lotus leaf extract 3% w/w). Raw and cooked samples were stored at 4 °C and the antioxidant activity was determined at 1, 3, 6 and 10 days. Antioxidant activity was significantly increased in all meat samples with the addition of both LRK and LL, but LRK was more effective against lipid oxidation. The results show the potential for using LRK and LL extracts in the meat industry to prolong shelf life.     

Research advances in traditional and modern use of Nelumbo nucifera: phytochemicals,health promoting activities and beyond

Abstract

Nelumbo nucifera, or sacred lotus, has been valuable for us to use as vegetable, functional food, and herb medicine for over 2,000?years. The purpose of this article is to systematically review the traditional/modern uses, chemical compositions and pharmacological activities on different parts of N. nucifera. Traditionally, this plant has been used to treat chronic dyspepsia, hematuria, insomnia, nervous disorders, cardiovascular diseases, and hyperlipidemia. Now, phytochemical investigations on different parts of N. nucifera have indicated a wide spectrum of at least 255 constituents belonging to different chemical groups, including proteins, amino acids, polysaccharides, starch, flavonoids, alkaloids, essential oils, triterpenoids, steroids, and glycosides. Meanwhile, its pharmacological activities, including anti-obesity, antioxidant, anti-inflammatory, cardiovascular, hepatoprotective, hypoglycemic, hypolipidemic, antitumor, memory-improving and antiviral activities, have also been reviewed, together with its applications in health food industry and clinic uses of its single plant or herbal formulae. Herein, this review will provide state-of-the-art overview on its traditional and modern uses in food industry and medicines, together with the comprehensive profiles of phytochemicals, and health promoting bioactivities of this valuable plant. In addition, the new perspectives and future challenges in the research on lotus are also outlined.     

Phenolic Compounds,Antioxidant Activity,and Medium Chain Fatty Acids Profiles of Coconut Water and Meat at Different Maturity Stages

Coconut is grown in tropical and subtropical areas worldwide. The endosperm (water and meat) is consumed and processed in different forms. This study investigated the antioxidant activities and identified the phenolic compounds existing in the water and meat of coconut fruits at three different maturity stages, i.e., 180, 190, and 225 days after pollination from two planting areas in Thailand. Total phenolic content and antioxidant activity indices increased as the coconut matured from 180 to 190 days after pollination and then decreased or remained unchanged at 225 days after pollination. Catechin and salicylic acid were the major phenolic compounds found in the water, while gallic, caffeic, salicylic, and p-coumaric acids were found in the meat. The fat content of the meat increased significantly with maturity stage. Medium chain fatty acids profiles were also analyzed. The results are important for producers, processors, and consumers to realize an optimal quality and functionality of coconut water and meat when used for specific purposes.     

Solar photocatalytically active,engineered silver nanoparticle synthesis using aqueous extract of mesocarp of Cocos nucifera (Red Spicata Dwarf)

ABSTRACT

Silver nanoparticles synthesised using aqueous extract of Cocos nucifera (CN) mesocarp were evaluated for their photocatalytic activity under solar irradiation. The silver nanoparticles were synthesised by a green method of harnessing bioactive phytocomponents from the mesocarp of Cocos nucifera. Large-scale application of this process necessitates the manoeuvering of the process parameters for increasing the conversion of silver ions to nanoparticles. Process parameters influencing the morphological characteristics of silver nanoparticles such as precursor salt concentration and pH of the synthesis mixture were studied. The crystalline nanoparticles were characterised using UV-vis spectroscopy, XRD, FTIR, SEM and EDX analysis. CN extract and 5 mM silver nitrate solution at a ratio of 1:4 (v/v) in the synthesis mixture was found to be the optimum. Alkaline initial pH of the synthesis mixture was found to favour the synthesis of smaller sized monodispersed silver nanoparticles. Solar energy was harnessed for the photocatalytic degradation of Malachite green dye using silver nanoparticles obtained through the green synthesis method. Overall process aims at utilisation of naturally available resource for the synthesis of silver nanoparticles as well as the degradation of dyes using these nanoparticles, making it useful in the treatment of wastewater.     

Antioxidant activities of extract and fractions from receptaculum nelumbinis and related flavonol glycosides

The antioxidant activities of ethanolic crude extract (ECE) and its four different solvent sub-fractions (namely, petroleum ether fraction (PEF), ethyl acetate fraction (EAF), n-butanol fraction (BF) and the aqueous fraction (AF) from the receptacles of Nelumbo nucifera Gaertn. (Receptaculum Nelumbinis) were investigated using two in vitro antioxidant assays. BF showed the highest total phenolic content (607.6 mg/g gallic acid equivalents), total flavonoid content (862.7 mg/g rutin equivalents) and total proanthocyanidin content (331.0 mg/g catechin equivalents), accompanied with the highest antioxidant activity compared to other fractions through 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. Five flavonol glycosides, namely hyperoside (1), isoquercitrin (2), quercetin-3-O-β-d-glucuronide (3), isorhamnetin-3-O-β-d-galactoside (4) and syringetin-3-O-β-d-glucoside (5) were isolated from the Receptaculum Nelumbinis. Compounds 2-5 were isolated for the first time from the Receptaculum Nelumbinis. The five isolated flavone glycosides, particularly compounds 1-3, demonstrated significant DPPH and ABTS radical scavenging activity, with IC(50) values of 8.9 ± 0.2, 5.2 ± 0.2, 7.5 ± 0.1 for DPPH and 114.2 ± 1.7, 112.8 ± 0.8, 172.5 ± 0.7 μg/mL for ABTS, respectively. These results suggest that Receptaculum Nelumbinis has strong antioxidant potential and may be potentially used as a safe and inexpensive bioactive source of natural antioxidants.