scholarly journals Caffeates and Caffeamides: Synthetic Methodologies and Their Antioxidant Properties

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Merly de Armas-Ricard ◽  
Enrique Ruiz-Reyes ◽  
Oney Ramírez-Rodríguez
Keyword(s):  
Chemical Synthesis ◽  
Caffeic Acid ◽  
Antioxidant Properties ◽  
Antibacterial Activities ◽  
Food Sources ◽  
Synthesis Methods ◽  
Chemical Structures ◽  
Synthetic Methodologies ◽  
Simple Molecules ◽  
Prevention Of Atherosclerosis

Polyphenols are secondary metabolites of plants and include a variety of chemical structures, from simple molecules such as phenolic acids to condensed tannins and highly polymerized compounds. Caffeic acid (3,4-dihydroxycinnamic acid) is one of the hydroxycinnamate metabolites more widely distributed in plant tissues. It is present in many food sources, including coffee drinks, blueberries, apples, and cider, and also in several medications of popular use, mainly those based on propolis. Its derivatives are also known to possess anti-inflammatory, antioxidant, antitumor, and antibacterial activities, and can contribute to the prevention of atherosclerosis and other cardiovascular diseases. This review is an overview of the available information about the chemical synthesis and antioxidant activity of caffeic acid derivatives. Considering the relevance of these compounds in human health, many of them have been the focus of reviews, taking as a center their obtaining from the plants. There are few revisions that compile the chemical synthesis methods, in this way, we consider that this review does an important contribution.

Synthesis and Antimicrobial activities of Some Polyphenol compounds by Nano ZnO-TBAB as a Heterogeneous Catalytic Media

2020 ◽  
Vol 17 ◽  
Author(s):  
Rahele Bargebid ◽  
Ali Khalafi-Nezhad ◽  
Kamiar Zomorodian ◽  
Leila Zamani ◽  
Ali Ahmadinejad ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Reusable Catalyst ◽  
Nano Zno ◽  
Antifungal Activities ◽  
Chemical Structures ◽  
Heterogeneous Catalytic ◽  
Solvent Free Conditions ◽  
New Compounds ◽  
Derivatives Of

Introduction: Mannich reaction is a typical example of a three-component condensation reaction and the chemistry of Mannich bases has been the matter of search by researchers. Here an efficient procedure for the synthesis of some new Mannich derivatives of simple phenols is described. Methods: In this procedure a microwave-assisted and solvent less condensation were done between different phenols, secondary amines and paraformaldehyde. The reactions proceed in the presence of catalytic amount of nano ZnO and tetrabutylammonium bromide (TBAB) in excellent yields. 10 new compounds were synthesized (A1-A10). Chemical structures of all new compounds were confirmed by different spectroscopic methods. We optimized the chemical reactions in different conditions. Optimization reactions were done in the presence of different mineral oxides, different amount of TBAB and also different solvents. Nano ZnO and TBAB in catalytic amounts and solvent free conditions were the best conditions. All the synthesized compounds were screened for their antimicrobial activities. Antifungal and antibacterial activities of the synthesized compounds were evaluated against some Candida, filaments fungi, gram positive and gram negative bacteria by broth micro dilution method as recommended by CLSI. Results: The result showed that compounds A2, A3 and A4 against most of the tested Candida species and compounds A5 and A7 against C. parapsilosis and C. tropicalis, exhibited considerable antifungal activities. Also Compounds A8 and A10 showed desirable antifungal activities against C. neoformance and C. parapsilosis, respectively. The antibacterial activities of the synthesized compounds were also evaluated. Compounds A6 - A10 against E. Fecalis and compounds A5, A7, A9 and A10 against P. aeruginosa showed desirable antibacterial activities. Discussion: We have synthesized some new Mannich adducts of poly-hydroxyl phenols in the presence of nano-ZnO as a reusable catalyst, with the hope of discovering new lead compounds serving as potent antimicrobial agents. The advantages of this method are generality, high yields with short reaction times, simplicity, low cost and matching with green chemistry protocols. The antimicriobial studies of Mannich derivatives of phenols showed desirable results in vitro.

scholarly journals Evaluation of the Antioxidant Properties and Aromatic Profile During Maturation of The Blackberry (Rubus glaucus Benth) and The Bilberry (Vaccinium meridionale Swartz)

2014 ◽  
Vol 67 (1) ◽  
pp. 7209-7218 ◽  
Author(s):  
Luisa Juana Bernal ◽  
Laura Angélica Melo ◽  
Consuelo Díaz Moreno
Keyword(s):  
Vitamin C ◽  
Caffeic Acid ◽  
Antioxidant Properties ◽  
Statistical Design ◽  
Anthocyanin Content ◽  
Total Phenols ◽  
Degenerative Diseases ◽  
Natural Sources ◽  
Three Stages ◽  
Preventive Role

The blackberry (Rubus glaucus Benth) and the bilberry (Vaccinium meridionale Swartz) are natural sources of antioxidants; they are known for their preventive role against degenerative diseases. In this study, the aromatic profile was evaluated using an electronic nose, including the antioxidant properties and the vitamin C, phenolic and anthocyanin contents during three stages of blackberry and bilberry ripening. A completely random statistical design was followed and the results presented differences in the aromatic profile: a higher anthocyanin content (1.59 mg of cyn-3-glu g-1 in the bilberry and 0.26 mg of cyn-3-glu g-1 in the blackberry) and total phenols (5.57 mg of caffeic acid g-1 bilberry and 2.68 mg caffeic acid g-1 blackberry). The behavior of the evaluated properties was independent in each of the fruits.

scholarly journals Photoprotection and Skin Pigmentation: Melanin-Related Molecules and Some Other New Agents Obtained from Natural Sources

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1537 ◽  
Author(s):  
Francisco Solano
Keyword(s):  
Human Skin ◽  
Uv Light ◽  
Stratospheric Ozone ◽  
Skin Pigmentation ◽  
Antioxidant Properties ◽  
Sun Exposure ◽  
Marine Organisms ◽  
Electromagnetic Spectrum ◽  
Chemical Structures ◽  
Skin Lightening

Direct sun exposure is one of the most aggressive factors for human skin. Sun radiation contains a range of the electromagnetic spectrum including UV light. In addition to the stratospheric ozone layer filtering the most harmful UVC, human skin contains a photoprotective pigment called melanin to protect from UVB, UVA, and blue visible light. This pigment is a redox UV-absorbing agent and functions as a shield to prevent direct UV action on the DNA of epidermal cells. In addition, melanin indirectly scavenges reactive oxygenated species (ROS) formed during the UV-inducing oxidative stress on the skin. The amounts of melanin in the skin depend on the phototype. In most phenotypes, endogenous melanin is not enough for full protection, especially in the summertime. Thus, photoprotective molecules should be added to commercial sunscreens. These molecules should show UV-absorbing capacity to complement the intrinsic photoprotection of the cutaneous natural pigment. This review deals with (a) the use of exogenous melanin or melanin-related compounds to mimic endogenous melanin and (b) the use of a number of natural compounds from plants and marine organisms that can act as UV filters and ROS scavengers. These agents have antioxidant properties, but this feature usually is associated to skin-lightening action. In contrast, good photoprotectors would be able to enhance natural cutaneous pigmentation. This review examines flavonoids, one of the main groups of these agents, as well as new promising compounds with other chemical structures recently obtained from marine organisms.

scholarly journals GC-MS Assisted Phytoactive Chemical Compounds Identification and Profiling with Mineral Constituents from Biologically Active Extracts of Aerva javanica (Burm. f) Juss. ex Schult.

2018 ◽  
Vol 46 (2) ◽  
pp. 517-524
Author(s):  
Kandhan KARTHISHWARAN ◽  
Subban KAMALRAJ ◽  
Chelliah JAYABASKARAN ◽  
Shyam S. KURUP ◽  
Sabitha SAKKIR ◽  
...  
Keyword(s):  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Biologically Active ◽  
Scavenging Activity ◽  
Medicinal Uses ◽  
Chemical Structures ◽  
Aerial Parts ◽  
Mineral Constituents

Aerva javanica (Burm. f) Juss. ex Schult. (Family: Amaranthaceae) family is one of the traditional medicinal plant growing in the United Arab Emirates. Apart from studies related to some medicinal properties, phytochemical, GC MS compound characterization and biological activities still to be investigated. An experiment was conducted to determine the possible bioactive components with their chemical structures and elucidation of phytochemicals from the aerial parts of the plant. The macro and micro-mineral constituents and antioxidant activities were also evaluated. Aerial parts of A. javanica were extracted sequentially with hexane, chloroform, ethyl acetate, acetone, methanol by cold percolation method. Free radical scavenging and antioxidant properties of methanolic extract were evaluated by using in vitro antioxidant assays such as hydroxyl radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, superoxide radical scavenging activity and ABTS radical scavenging activity. Primary phytochemical and micro-macro element was tested using standard protocol. The chemical characterization was done with the help of Gas Chromatography-Mass Spectrometry (GC–MS), and the mass spectra of the total compounds in the extract were matched with the National Institute of Standard and Technology (NIST) library. Mineral constituents were identified and estimated by ICP-OES. Ninety-nine metabolites were obtained by GC-MS anslysis; indole was found to be major components followed by 2-Chlorallyl diethyldithiocarbamate (CDEC), Carbaril, Bis(2-ethylhexyl) phthalate, Quinoline, 4H-Cyclopenta[def]phenanthrene,2-[Bis(2-chloroethylamino)]-tetrahydro-2H-1,3,2-oxazaphosphorine-2-oxide, Phenobarbital, 1H-Indole, 2-methyl-, 2,3,7,8-Tetrachlorodibenzo-p-dioxin Disulfide, diphenyl. The presence of various bioactive compounds in the extract validates the traditional medicinal uses of this plant.

scholarly journals BERGENIA CILIATA: ISOLATION OF ACTIVE FLAVONOIDS, GC-MS ANALYSIS, ADME STUDY AND INHIBITION ACTIVITY OF OXALATE SYNTHESIZING ENZYMES

2021 ◽  
pp. 34-46
Author(s):  
SHWETA R. GOPHANE ◽  
SAGAR R. JADHAO ◽  
PREETI B. JAMDHADE
Keyword(s):  
Lactate Dehydrogenase ◽  
Ethyl Acetate ◽  
Competitive Inhibition ◽  
Active Role ◽  
Glycolate Oxidase ◽  
Gas Chromatography Mass Spectrometry ◽  
Synthesis Methods ◽  
Lactate Dehydrogenase Activity ◽  
Chemical Structures ◽  
Ms Analysis

Objective: Bergenia ciliata (family-Saxifragaceae) is a well-known herb for kidney stone. The main objective of the study was the identification of flavonoids along with ADME profile. Another supportive objective was to check inhibition of enzymes which perform active role in oxalate synthesis. Methods: The hydromethanolic extract was fractionated by liquid-liquid extraction to obtain ethyl acetate and ethyl ether fractions. The chemical structures of the purified compounds were identified by gas chromatography-mass spectrometry. Results: A total of 12 volatile chemical compounds belonging to hydrocarbons, esters, alcohols, fatty acids, ketones, etc. were identified and characterized in ethyl acetate fraction through GC-MS analysis Fractions enriched in flavonoids showed glycolate oxidase and lactate dehydrogenase enzyme inhibition with IC50 value (µg/ml) 65.76 and 69.84 respectively. The kinetic behaviour of the extracts that inhibit the Glycolate oxidase and Lactate dehydrogenase activity was determined by the Lineweaver-Burk plot. The mode of inhibition of the studied plant extract was type of a non-competitive inhibition. ADMET screening of compounds successfully passed all the parameters of screening. Conclusion: On the basis of the results, it was found that Bergenia ciliata (rhizome) may serve as a novel and rich source of therapeutic compounds and it can be further explored for urolithiasis treatment purposes.

scholarly journals PALYNOLOGICAL ORIGIN, PHENOLIC CONTENT AND ANTIOXIDANT PROPERTIES OF GEOPROPOLIS COLLECTED BY MANDAÇAIA (MELIPONA MANDACAIA) STINGLESS

2020 ◽  
Vol 33 (1) ◽  
pp. 246-252
Author(s):  
PAULO RICARDO DA SILVA ◽  
TELMA MARIA GUEDES DA SILVA ◽  
CELSO AMORIM CAMARA ◽  
EVA MÔNICA SARMENTO DA SILVA ◽  
FRANCISCO DE ASSIS RIBEIRO DOS SANTOS ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Phenolic Content ◽  
Antioxidant Properties ◽  
Northeastern Brazil ◽  
Food Sources ◽  
Potential Health ◽  
Pollen Types ◽  
Strong Relation ◽  
Β Carotene

ABSTRACT The stingless bee Melipona mandacaia (Smith 1863) (mandaçaia) is found only in the region of Caatinga, Northeastern Brazil, in the states of Bahia and Pernambuco, near to São Francisco river. The aim of the present work was to determine the botanical origin and to evaluate the phenolic content and antioxidant properties (β-carotene/linoleic acid system, DPPH and ABTS scavenging) of mandaçaia geopropolis. 25 pollen types from 15 families were identified from the 9 geopropolis samples analyzed. Phenolic compounds content varied between all the geopropolis EtOH extracts, hexane, EtOAc and MeOH:H2O fractions. The main pollens found in the geopropolis samples were from the Leguminoseae family. This identification of meliponicultural plants is extremely important because it indicates the food sources used for the collection of nectar and pollen. Our results revealed that there is a strong relation between the phenolic compounds and the antioxidant activity. These results showed that total phenols of mandaçaia geopropolis may be responsible for the antioxidant activity with evidence that it's a rich source of phenols bioactive compounds with potential health benefits.

Rheology of Block Copolymers

2007 ◽  
Author(s):  
Chang Dae Han
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Block Copolymers ◽  
Small Angle ◽  
Volume Fraction ◽  
Synthesis Methods ◽  
Chemical Structures ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Molecular Weight Form

Block copolymer consists of two or more long blocks with dissimilar chemical structures which are chemically connected. There are different architectures of block copolymers, namely, AB-type diblock, ABA-type triblock, ABC-type triblock, and AmBn radial or star-shaped block copolymers, as shown schematically in Figure 8.1. The majority of block copolymers has long been synthesized by sequential anionic polymerization, which gives rise to narrow molecular weight distribution, although other synthesis methods (e.g., cationic polymerization, atom transfer radical polymerization) have also been developed in the more recent past. Owing to immiscibility between the constituent blocks, block copolymers above a certain threshold molecular weight form microdomains (10–50 nm in size), the structure of which depends primarily on block composition (or block length ratio). The presence of microdomains confers unique mechanical properties to block copolymers. There are many papers that have dealt with the synthesis and physical/mechanical properties of block copolymers, too many to cite them all here. There are monographs describing the synthesis and physical properties of block copolymers (Aggarwal 1970; Burke and Weiss 1973; Hamley 1998; Holden et al. 1996; Hsieh and Quirk 1996; Noshay and McGrath 1977). Figure 8.2 shows schematically four types of equilibrium microdomain structures observed in block copolymers. Referring to Figure 8.2, it is well established (Helfand and Wasserman 1982; Leibler 1980) that in microphase-separated block copolymers, spherical microdomains are observed when the volume fraction f of one of the blocks is less than approximately 0.15, hexagonally packed cylindrical microdomains are observed when the value of f is between approximately 0.15 and 0.44, and lamellar microdomains are observed when the value of f is between approximately 0.44 and 0.50. Some investigators have observed ordered bicontinuous double-diamonds (OBDD) (Thomas et al. 1986; Hasegawa et al. 1987) or bicontinuous gyroids (Hajduk et al. 1994) at a very narrow range of f (say, between approximately 0.35 and 0.40) for certain block copolymers. Figure 8.2 shows only one half of the symmetricity about f = 0.5. Transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and small-angle neutron scattering (SANS) have long been used to investigate the types of microdomain structures in block copolymers.

scholarly journals Application of Natural Flavonoids to Impart Antioxidant and Antibacterial Activities to Polyamide Fiber for Health Care Applications

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 301 ◽  
Author(s):  
Ya-Dong Li ◽  
Jin-Ping Guan ◽  
Ren-Cheng Tang ◽  
Yi-Fan Qiao
Keyword(s):  
Health Care ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Chemical Structures ◽  
Functional Textiles ◽  
Washing Durability ◽  
Polyamide Fiber ◽  
Adsorption Capability

Polyamide fiber has the requirements for antioxidant and antibacterial properties when applied to produce functional textiles for heath care purposes. In this work, three natural flavonoids (baicalin, quercetin, and rutin) were used to simultaneously impart antioxidant and antibacterial functions to polyamide fiber using an adsorption technology. The relations of the chemical structures of flavonoids with their adsorption capability, adsorption mechanisms, and antioxidant and antibacterial activities were discussed. The Langmuir–Nernst adsorption model fitted the adsorption isotherms of the three flavonoids well. The adsorption kinetics of the three flavonoids conformed to the pseudo second-order kinetic model. Quercetin exhibited the highest affinity and adsorption capability, and imparted the highest antioxidant and antibacterial activities to polyamide fiber; and moreover, its antioxidant and antibacterial functions had good washing durability. This study demonstrates that the treatment using natural flavonoids is an effective way to exhance the health care functions of polyamide fiber.

scholarly journals Cytotoxic and antioxidant potentials of ellagic acid derivatives from Conocarpus lancifolius (Combretaceae)

2020 ◽  
Vol 19 (5) ◽  
pp. 1037-1080
Author(s):  
Malik Saadullah ◽  
Muhammad Asif ◽  
Abdul Sattar ◽  
Kanwal Rehman ◽  
Shahid Shah ◽  
...  
Keyword(s):  
Ellagic Acid ◽  
Antioxidant Properties ◽  
Human Colon ◽  
Antioxidant Compounds ◽  
Phytochemical Analysis ◽  
Human Colon Cancer ◽  
Chemical Structures ◽  
Ellagic Acid Derivatives ◽  
Layer Chromatography

Purpose: Isolation, characterisation and structure elucidation of compounds obtained from Conocarpus lancifolius and screening of their pharmacological effects in vitro.Methods: After collection, authentication and extraction from whole C. lancifolius plants, screening for secondary metabolites, thin-layer  chromatography and subsequent open column chromatography were performed for phytochemical analysis and subsequent purification of the compounds. The chemical structures of the isolated compounds were elucidated using spectroscopic (UV-visible, infrared and mass) spectroscopy, and nuclear magnetic resonance (1H-NMR, 13C-NMR including BB, DEPT-135, 90 and two-dimensional correlation techniques, including HMBC and HSQC). The cytotoxic and antioxidant potentials of extracts and compounds obtained from C. lancifolius were evaluated using in vitro models.Results: Two ellagic acid derivatives, 2,3,8-tri-o-methylellagic acid (A) and 3-O-methylellagic acid 4-O-β-D-glucopyranoside (B), were isolated. Both compounds (A and B) were cytotoxic in a variety of cancer cell lines, including murine lymphocytic leukaemia (P-388, half-maximal inhibitory concentration (IC50) =3.60 and 2.40 μg/mL, respectively), human colon cancer (Col-2, IC50 = 0.76 and 0.92 μg/mL, respectively) and human breast cancer (MCF-7, IC50 = 0.65 and 0.54 μg/mL, respectively). Moreover, both compounds showed significant antioxidant potential in vitro.Conclusion: C. lancifolius extract and isolated ellagic acid derivatives (compounds A and B) possess cytotoxic and antioxidant properties. These findings suggest that C. lancifolius contains bioactive compounds that can be potentially developed as natural cytotoxic and antioxidant compounds. Keywords: Conocarpus lancifolius, Ellagic acid, Combretaceae, Cytotoxic activity, Antioxidant

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