Characterization and identification of the mucilage extracted from orchid bulbs (Bletia campanulata) by high temperature capillary gas chromatography (HT-CGC)

The aim of this work was to develop an analytical method by High Temperature Capillary Gas Chromatography (HT-CGC) to characterize and identify the presence of tzauhtli, orchid mucilage, in works of art. During the pre-Hispanic and colonial period, tzauhtli was used as an adhesive for paper and feathers, as well as paint binder, and was one of the components of the paste used to model corn stalk sculptures. The mucilage was extracted with hot water from orchid bulbs (Bletia campanulata) and lyophilized. The free sugars from the mucilage were analyzed by CGC after derivatization. The polysaccharide of the mucilage was characterized after its partial acid hydrolysis by HT-CGC analysis of the oligosaccharides obtained. The proposed chromatographic method allows the identification of different mucilages in works of art. This contribution is the first report of the oligosaccharides from the hydrolysis of the mucilage extracted from orchid bulbs (Bletia campanulata).     

An acidic polysaccharide having immunological activities from the rhizome of Cnidium officinale.

An acidic polysaccharide, designated as cnidirhan AG, was isolated from the rhizomes of Cnidium officinale Makino. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 5.1 x 10(4). It showed pronounced reticuloendothelial system-potentiating activity in a carbon clearance test, and had a remarkable effect on both anti-complementary and alkaline phosphatase-inducing activities. It is composed of L-arabinose: D-galactose: D-glucuronic acid in the molar ratio of 2:6:1, in addition to small amounts of O-acetyl groups. Methylation analysis, carbon-13 nuclear magnetic resonance, controlled Smith degradation and limited acid hydrolysis indicated that the core structural features of cnidirhan AG include a backbone chain composed of beta-1,3-linked D-galactose residues. Some of the galactose units in the backbone carry beta-D-galactosyl side chains at position 6. Both alpha-L-arabinosyl arabinose side chains and terminal beta-D-glucuronic acid residues are linked to the core galactan units.     

Development and Characterization of Novel Biopolymer Derived from Abelmoschus esculentus L. Extract and Its Antidiabetic Potential

Abelmoschus esculentus (Okra) is an important vegetable crop, widely cultivated around the world due to its high nutritional significance along with several health benefits. Different parts of okra including its mucilage have been currently studied for its role in various therapeutic applications. Therefore, we aimed to develop and characterize the okra mucilage biopolymer (OMB) for its physicochemical properties as well as to evaluate its in vitro antidiabetic activity. The characterization of OMB using Fourier-transform infrared spectroscopy (FT-IR) revealed that okra mucilage containing polysaccharides lies in the bandwidth of 3279 and 1030 cm⁻¹, which constitutes the fingerprint region of the spectrum. In addition, physicochemical parameters such as percentage yield, percentage solubility, and swelling index were found to be 2.66%, 96.9%, and 5, respectively. A mineral analysis of newly developed biopolymers showed a substantial amount of calcium (412 mg/100 g), potassium (418 mg/100 g), phosphorus (60 mg/100 g), iron (47 mg/100 g), zinc (16 mg/100 g), and sodium (9 mg/100 g). The significant antidiabetic potential of OMB was demonstrated using α-amylase and α-glucosidase enzyme inhibitory assay. Further investigations are required to explore the newly developed biopolymer for its toxicity, efficacy, and its possible utilization in food, nutraceutical, as well as pharmaceutical industries.     

Excellent lubricating behavior of Brasenia schreberi mucilage

The present work reports an excellent lubrication property of an aquatic plant called Brasenia schreberi (BS). To investigate the lubrication characteristics of the BS mucilage, a novel measuring system is designed, and an ultralow friction coefficient about 0.005 between the mucilage and glass surface has been obtained. It is found that the ultralow friction is closely related to the structure of mucilage and water molecules in the mucilage. The microstructure analysis indicates that the mucilage surrounding BS forms a kind of polysaccharide gel with many nanosheets. A possible lubrication mechanism is proposed that the formation of hydration layers among these polymer nanosheets with plenty of bonded water molecules causes the ultralow friction. The excellent lubrication property has a potential application for reducing the friction between a glossy pill coated with such layer of mucilage and people's throats.     

<Emphasis Type="Italic">P. psyllium</Emphasis>-<Emphasis Type="Italic">g</Emphasis>-polyacrylonitrile: synthesis and characterization

P. psyllium mucilage, an anionic natural polysaccharide consisting of pentosan and uronic acid obtained from the seeds of Plantago psyllium (Plantago family), was grafted with acrylonitrile (AN). Graft copolymers were prepared by grafting acrylonitrile onto P. psyllium mucilage (PSY) using ceric ion initiated solution polymerization technique for the very first time. The influence of varying concentration of (AN) and ceric ammonium nitrate (CAN) on graft copolymerization was studied. The percent grafting was found to be affected by the concentrations of AN and CAN in the reaction mixture. The prepared copolymers were not soluble in any common solvent or mixture of solvents. The prepared copolymers were characterized by FTIR.     

Characterization of carbohydrates in mucilage samples from the northern Adriatic Sea

Carbohydrate contents in seawater, mucilage, and mucilage interstitial waters were analyzed during episodes of mucilage formation in the summers of 2000 and 2001 in the northern Adriatic Sea off Pesaro and in the Gulf of Trieste using 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and 2,4,6-tripyridyl-s-triazine (TPTZ) assays. The significant presence of polysaccharides in seawater in the presence of mucilage has an important impact on the agglomeration processes forming gelatinous material (macrogels). Characterization of oligosaccharides in the water-soluble fraction of mucilage using HPLC/RI revealed maltose and pentaose as the main components.     

The enantioselective metabolism of p-cymene in rabbits.

p-Cymene (1) was metabolized in rabbits and the following four optically active metabolites, 2-(p-tolyl)-1-propanol (3': R/S = 65:35), 2-(p-tolyl)propanoic acid (5': R/S = 0:100), p-(2-hydroxy-1-methylethyl)benzoic acid (6': R/S = 91:9) and p-(1-carboxyethyl)benzoic acid (8': R/S = 30:70), were isolated in addition to three optically inactive metabolites, 2-(p-tolyl)-2-propanol (2), p-isopropylbenzoic acid (4'), and p-(1-hydroxy-1-methylethyl)benzoic acid (7'). The presumed metabolic pathways of p-cymene in rabbits were confirmed by the administration of the intermediate metabolites (2, 3', 4', and 5'). The enantiomeric ratios of the metabolites, 3' and 6', suggested that omega-hydroxylations of the isopropyl group in 1 and 4' occurred preferentially at the pro-S methyl group. In the metabolism of 1, the S-isomers are predominant in the propanoic acid derivatives, but the R-isomers are rich in the propanol derivatives. It is of interest that the metabolism of 4', however, produced predominantly the corresponding propanol derivative (6'; R/S = 91:9) and propanoic acid derivative (8'; R/S = 80:20) possessing the same R-configuration. Some optically active p-cymene derivatives were also synthesized as standard compounds.     

Production of a new mucilage compound in Lepidium sativum callus by optimizing in vitro growth conditions

The mucilage in Lepidium sativum L. is considered a biologically active compound with diverse medicinal properties. Different explants (hypocotyls and leaf) were transferred to Murashige and Skoog (MS) medium supplemented with twelve different plant growth regulator combinations under two different incubations (light and dark). The best mucilage production from callus (36.76% g g^?1 dry weight) was obtained in the MS medium supplemented with 1 mg L^?1 of 2, 4-D and 2 mg L^?1 of BAP under the light condition. The mucilage produced by callus culture was nearly three times more than the mucilage yield of the seeds. The glucose, arabinose + mannose and galactose were 43.4 (mg g^?1 DW), 195.3 (mg g^?1 DW) and 86.2 (mg g^?1 DW) in the mucilage originated from seed, callus leaf and callus hypocotyl, respectively. The present study proposes an efficient method for producing large scales of mucilage with a favorable sugar aimed at food or pharmaceutical industries.     

Characterization of a polysaccharide having activity on the reticuloendothelial system from the stolon of Glycyrrhiza glabra var. glandulifera.

An acidic polysaccharide, named glycyrrhizan GA, was isolated from the stolon of Glycyrrhiza glabra L. var. glandulifera Reg. et Herd. It produced a single band on electrophoresis and a single peak on gel chromatography, and its molecular mass was estimated to be 85,000. Glycyrrhizan GA is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid: D-glucuronic acid in the molar ratio of 22:10:1:2:1, in addition to small amounts of O-acetyl groups. Part of the hexuronic acid residues exist as methyl esters. Methylation analysis, carbon-13 nuclear magnetic resonance and periodate oxidation studies indicated that its structural features include mainly alpha-arabino-beta-3,6-galactan type structural units. Glycyrrhizan GA showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test.     

Constituents of the seed of Malva verticillata. VI. Characterization and immunological activities of a novel acidic polysaccharide

A novel acidic polysaccharide, designated as MVS-VI, was isolated from the seeds of Malva verticillata L. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 26000. It is composed of L-arabinose: D-xylose: D-galactose: D-glucose: L-rhamnose: D-galacturonic acid in the molar ratio of 30: 15: 20: 3: 2: 10, in addition to small amounts of peptide moiety. Methylation analysis, carbon-13 nuclear magnetic resonance and periodate oxidation studies indicated its structural features to have mainly acidic alpha-arabino-3,6-beta-galactan type structural units. MVS-VI showed significant reticuloendothelial system-potentiating activity in a carbon clearance test, and it possesses remarkable anti-complementary activity.     

Multiple-physiological benefits of bird’s nest fern (Asplenium australasicum) frond extract for dermatological applications

p-coumaric acid and fucose-rich polysaccharide have been studied for many bio-functions in skin including cutaneous protection from oxidative damage and antiageing, respectively, as well as wound healing. The physiological activities of various bird’s nest fern extracts (BNFE), containing considerable fucose-rich mucilage and p-coumaric acid, on fibroblast and human skin were first investigated. BNFE with higher polysaccharide content generally contributed to a better moisture holding capability. Furthermore, BNFE showed pronouncedly enhancing effect on collagen production and growth of fibroblast (NIH-3T3), clinical trial results revealed that the emulsions with 1% BNFE showed good moisturising effect and improved the elasticity of human skins effectively. The potential of BNFE for cosmetics and medical applications such as natural moisturiser, antiageing and wound repairing was possibly related to the fucose-rich mucilage and various phenolic compounds including p-coumaric acid in BNFE.     

Nano Milk Protein-Mucilage Complexes: Characterization and Anticancer Effect

The anticancer activity of natural compounds has recently attracted multidisciplinary research. In this study, the complexation of milk proteins (MP) with Isabgol husk mucilage (IHM) and Ziziphus spina-christi mucilage (NabM) was investigated. In this context, the physicochemical properties of milk protein mucilage complexes (MPMC) including pH, Carr’s index, water solubility, and water absorption indices were measured, and the flow behavior was studied. In addition, the amino acid profile, protein digestibility, and phenolic and flavonoids content of MPMC were explored, and the microstructure of the complexes was visualized using transmission electron microscopy. The antioxidant and anticancer potencies of MPMC against two cancerous cell lines, human liver cancer HEPG-2 and breast cancer MCF-7, in comparison with two normal cell lines, namely, Bj-1 and MCF-12F, were tested using neutral red uptake assay. The results revealed that MPMC had scavenging activity against DPPH, ABTS, and HS radicals. Moreover, MPMC has the potential to prevent DNA damage induced by oxidative stress in Type-Fenton’s reaction. The results of the neutral red assay showed significant growth inhibition of both HEPG-2, MCF-7, whereas no significant cytotoxic effect was detected against Bj-1 and MCF-12F. RT-qPCR results indicated MPMC stimulated apoptosis as revealed by the upregulation of the pro-apoptosis gene markers Casepase-3, p53, Bax. Meanwhile, the anti-apoptosis Bcl-2 gene was downregulated. However, no significant difference was observed in normal cell lines treated with MPMC. In conclusion, MPMC can be considered as a promising anticancer entity that can be used in the development of novel cancer therapeutics with comparable activity and minimal side effects compared to conventional cancer chemotherapies.     

3-Oxo-1,2-benzoisothiazoline-2-acetic acid 1,1-dioxide derivatives. I. Reaction of esters with alkoxides

Reaction of 3-oxo-1,2-benzoisothiazoline-2-acetic acid alkyl esters 1,1-dioxide ( 1a-d ) with alkaline alkoxides was carried out under various conditions. Under mild conditions, o-(N-carboxymethylsulfamyl)benzoic acids dialkyl esters ( 2a-d ) were obtained with good yields. Reaction of 1a-d or 2a-d with sodium alkoxides under drastic conditions afforded 4-hydroxy-2H-1,2-benzothiazine-3-carboxylic acid alkyl esters 1,1-dioxide ( 3a-d ). Transesterification was observed when esters 1b-d were treated with sodium methoxide in methanol. Esters 3a-d were hydrolyzed in concentrated aqueous sodium hydroxide affording the acid 6 . Attempts to recrystallize 6 from water resulted in its decarboxylation to give 2H-1,2-benzothiazine-4-(3H)one 1,1-dioxide (7). Compound 6 could not be obtained by acid hydrolysis of esters 3a-d or by rearrangement of 3-oxo-1,2-benzoisothiazoline-2-acetic acid 1,1-dioxide ( 8 ). Different experimental evidence supports the suggestion that rearrangement took place by ethanolysis of the carboxamide linkage affording the open sulfonamides (fast step) followed by a Dieckmann cyclization (slow step). It was demonstrated that transesterification took place in the open sulfonamides 2 .     

Tamarindus indica mucilage and its acrylamide-grafted copolymer as flocculants for removal of dyes

The application of Tamarindus indica seed mucilage (Tam), a food grade polysaccharide, and its acrylamide grafted copolymer as flocculants was assessed for the first time for removal of various types of dyes from model textile wastewater containing azo, basic, and reactive dyes. Acrylamide grafted T. indica mucilage (Tam-g-PAM) was obtained by ceric ion initiated polymerization technique. A series of contact time experiments were conducted to assess the system variables such as concentrations of mucilage and dyes and pH. These flocculants reduce the dye concentration by flocculation and settling. The grafted copolymer, Tam-g-PAM showed better results for dye removal. The optimal flocculant concentration, which was required to effect flocculation, was independent of dye concentration within the range examined. Both the flocculants performed better for removal of azo dyes than for reactive and basic dyes.     

Reticuloendothelial system-potentiating and alkaline phosphatase-inducing activities of Plantago-mucilage A, the main mucilage from the seed of Plantago asiatica, and its five modification products.

Five kinds of chemically modified products were prepared from Plantago-mucilage A, the representative mucous polysaccharide isolated from the seed of Plantago asiatica L., and their reticuloendothelial system-potentiating and alkaline phosphatase-inducing activities have been investigated. Both activities were markedly enhanced when the mucilage was de-O-acetylated. The products obtained by periodate oxidation, controlled Smith degradation, and partial acid hydrolysis under the two conditions were not effective. Structural features of the partial hydrolyzates were elucidated, and it was shown that these products lost all O-acetyl groups, all xylose branches and many hexuronosyl arabinose side chains.     

Liquid-liquid extraction of zirconium from hafnium and other elements with dicyclohexyl-18-crown-6

Zirconium was quantitatively extracted with 2.5 × 10^?2 M dicyclohexyl-18-crown-6 in dichloromethane from 8.5 M hydrochloric acid. It was stripped with 0.5 M hydrochloric acid and was determined spectrophotometrically as its complex with Arsenazo III. Hafnium was not extracted under these conditions, but from the residual aqueous phase it was extracted with 7.0 × 10^?2 M dicyclohexyl-18-crown-6 in dichloromethane from 9.0 M hydrochloric acid. It was stripped with 0.1 M perchloric acid and determined spectrophotometrically at 540 nm as its complex with xylenol orange. The separation of zirconium and hafnium from other metals is also described.     

Electrophilic Aromatic Substitution of Groups other than Hydrogen. Part I: Ipso Factors and Rate-Limiting Steps in Dehalogenations by Diazonium Ions. 26th communication on diazo coupling reactions

The rates of substitution of the group X in 1-X-2-naphthol-6-sulfonic acids (X = H, Cl, Br, and I) by p-chlorobenzenediazonium ions in aqueous solution have been measured. The rates of the halogenated naphthols relative to that of the parent compound (X = H) are 0.0070:0.0089:0.149 for X = Cl, Br, and I respectively. The reaction of 1-bromo-2-naphthol-6-sulfonic acid is catalysed by thiosulfate ions; the relative rate observed for this compound does not, therefore, represent the ipso factor. It is postulated that in its substitution the release of the electrofugal leaving group (Br^⊕) is rate-limiting.     

Zur Reaktionsweise von Enaminen mit Cyclopropenonen V. Einsatz von β-Carbonyl-enaminen

Diphenylcyclopropenone ( 10 ) was heated with five different β-carbonyl-enamines, namely 4-pyrrolidino-pent-3 E-en-2-one ( 12 ), 4-dimethylamino-pent-3E-en-2-one ( 13 ), 4-dimethylamino-but-E-en-2-one ( 14 ), 3-dimethylamino-1-phenyl-prop-E-en-1-one ( 15 ) and ethyl 3-pyrrolidino-isocrotonate ( 16 ). The resulting reactions were more sluggish than those of 10 with ordinary enamines. The main reaction (between 10 and 69% yield) was in all cases a ‘C, N-insertion’. The major products were: from 12 : an inseparable mixture of 4-methyl-6-oxo-2,3-diphenyl-hepta-2E, 4E-dienoic acid pyrrolidide ( 17 ) and its 2Z, 4E-stereomer ( 18 ); from 13 : 4-methyl-6-oxo-2, 3-diphenyl-hepta-2E-dienoic acid dimethylamide ( 19 ) and its 2Z, 4E-stereomer ( 20 ); from 14 : 6-oxo-2, 3-diphenyl-hepta-2E, 4E-dienoic acid dimethylamide ( 21 ); from 15 : 6-oxo-2,3,6-triphenyl-hexa-2E, 4E-dienoic acid dimethylamide ( 22 ); and from 16 : 5-ethoxycarbonyl-4-methyl-2, 3-diphenyl-penta-2E, 4E-dienoic acid pyrrolidide ( 23 ) and its 2Z, 4E-stereomer ( 24 ). The constitutions of 17 to 24 were derived mainly from spectral properties. For these products the E-configuration at the 4,5-double bond was assigned on the assumption that the insertion of the side-chain (cyclopropenone carbons) between the enamine carbon and nitrogen atoms occurred with retention of configuration, as had been concluded earlier. This was confirmed in the cases of 21 and 22 by the trans-coupling between H? C(4) and H? C(5) in the ¹H? NMR. spectrum, the educts ( 14 and 15 ) having the E-configuration. The configurational difference between the stereomeric products 17 / 18 , 19 / 20 and 23 / 24 was, therefore attributed to the 2,3-double bond. This was confirmed by aqueous acid treatment in the case of the pair 19 / 20 : The 2E-configuration for 19 followed from its conversion to 4-acetonyl-4-methyl- 2,3-diphenyl-isocrotonolactone ( 25 ) and the 2Z-configuration of 20 by its conversion first to a mixture ol two diastereomers of (presumably) 1-acetyl-4-dimethylaminocarbonyl-2-methyl-3- phenyl-l,4-dihydronaphthalene ( 27a ) and then, under more drastic conditions, to 6-methyl-11H-benzo[a]fluorene ( 26 ).The structures of 25 and of 26 were derived from their spectral properties, and that of the 27a -mixture was made probable by the plausibility of its intermediacy on the way to 26 . A pathway for the conversion of 20 to 27a (scheme 3) and of the latter to 26 (scheme 4)is proposed. In the case of the reaction of 10 with 12 , two stereomeric basic by-products were isolated (combined yield 150/,). Their structures as traw- and cis-4-acetonyl-4,5-diphenyl-3-pyrrolidinocyclopent-2-en-ones ( 30 and 31 ) were deduced from their spectral properties and from those of their hydrochlorides 32 and 33 . The enamino-ketone function was found to be resistant to a number of reagents, among which were excess sodium borohydride, which converted 30 to the secondary alcohol 34 , and excess methyllithium, which converted 31 to the tertiary alcohol 35 . A mechanism (called ‘rearrangement’) is proposed (scheme 5) for the formation of the enaminoketones (such as 30 and 31 ), which proceeds via the same ammonio-enolate intermediate ( 36 ) which plays a role in the formation of the major products, the amides (such as 17 to 24 ). It is suggested (scheme 6) that the 3-membered ring of the ammonio-enolate 40 may open in three ways, one of which leads to the amides and another to the enamino-ketones.     

有机膦、胂、睇合钨钼聚多酸盐的研究——Ⅷ.3-硝基-4-羟基苯胂合钼聚多酸盐的制备和解聚法制备有机胂合钼聚多酸盐的尝试

为研究有机基团对有机胂合钼聚多酸盐类型的影响,试验了3-硝基-4-羟基苯胂酸与钼酸钠在pH为3～5条件下的反应。制得了两种新化合物:(1)(NH_4)_6[(3-NO_2-4-OHC_6H_3As)_2Mo_6O_(25)](2)(CN_3H_6)_6[(3-NO_2-4-OHC_6H_3As)_2Mo_6O_(25)]。报道和讨论了它们的红外、可见与紫外光谱、热分解性质和电化学氧化还原性质。它们与其钨同系物类型相同。化合物(1)可用酸化聚合法及解聚法制得,经过实验比较证实了以七钼酸铵为原料的解聚法具有产物纯化方便、得率高的优点。     

An acidic polysaccharide having activity on the reticuloendothelial system from the root of Astragalus mongholicus.

An acidic polysaccharide, designated as AMon-S, was isolated from the roots of Astragalus mongholicus BUNGE. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 7.6 x 10(4). It showed significant reticuloendothelial system-potentiating activity in a carbon clearance test. It is composed of L-arabinose: D-galactose: D-galacturonic acid: D-glucuronic acid in the molar ratio of 18:18:1:1, in addition to small amounts of O-acetyl groups and peptide moiety. A part of the hexuronic acid residues exist as the methyl esters. Methylation analysis, carbon-13 nuclear magnetic resonance and periodate oxidation studies enabled elucidation of its structural features and revealed mainly alpha-arabino-beta-3,6-galactan type structural units.