Clam-shaped cyclam-functionalized porphyrin for electrochemical reduction of carbon dioxide

A clam-shaped molecule comprising a Zn(II)-porphyrin and a Zn(II)-cyclam is synthesized and characterized. Its electrochemical behavior and catalytic activity for homogeneous electrochemical reduction of carbon dioxide (CO[Formula: see text] are investigated by cyclic voltammetry and compared with those of Zn(II)-meso-tetraphenylporphyrin and Zn(II)-cyclam. Under N2-saturated conditions, cyclic voltammetry of the featured complex has characteristics of its two constituents, but under CO2-saturated conditions, the target compound exhibits significant current enhancement. Iterative reduction under electrochemical conditions indicated the target compound has improved stability relative to Zn(II)-cyclam. Controlled potential electrolysis demonstrates that, without addition of water, methane (CH[Formula: see text] is the only detectable product with 1% Faradaic efficiency (FE). The formation of CH4 is not observed under the catalysis of the Zn(II)-porphyrin benchmark compound, indicating that the CO2-capturing function of the Zn(II)-cyclam unit contributes to the catalysis. Upon addition of 3% v/v water, the electrochemical reduction of CO2 in the presence of the target compound gives carbon monoxide (CO) with 28% FE. Dominance of CO formation under these conditions suggests enhancement of proton-coupled reduction. Integrated action of these Zn(II)-porphyrin and Zn(II)-cyclam units offers a notable example of a molecular catalytic system where the cyclam ring captures and brings CO2 into the proximity of the porphyrin catalysis center.

Clinical evaluation of Gac extract (Momordica cochinchinensis) in an antiwrinkle cream formulation

The objective of this work was to evaluate the antioxidant and antityrosinase activities of Gac (Momordica cochinchinensis) extract and to clinically evaluate a Gac-containing antiwrinkle cream formulation. Gac extract exhibited higher antioxidant activity than vitamin C or E, as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH, 41.25 ± 0.34 mg TEAC/ml extract), 2, 2'-azinobis 3-ethylbenzothialine-6-sulfonic acid (ABTS, 47.70 ± 0.18 mg TEAC/ml extract), and ferric reducing antioxidant power (FRAP, 105.03 ± 2.326 mg TEAC/ml extract) scavenging. The antioxidant activity of Gac extract was 5.85- and 11.75-fold higher than that of vitamin E in the DPPH and ABTS assays, respectively. The FRAP assay indicated that the antioxidant activity of Gac extract was 2.91-fold higher than that of vitamin C. Gac extract also exhibited high tyrosinase inhibition (62.83% ± 1.99%). The tyrosinase inhibition activity of Gac extract was 1.51- and 2.06-fold greater than that of vitamins C and E, respectively. The safety and efficacy of the formulated Gac extract cream as an antiwrinkle agent and its promotion of skin moisturization and smoothness were investigated. Evaluation of acute skin tolerance indicated nonirritating properties. A clinical study revealed increases in cutaneous hydration. Average roughness was decreased, while smoothness was increased. Skin overlook analysis indicated skin roughness relief. These results indicate that the formulated Gac extract product is an effective antiwrinkle cream.

Rapidly stopping hemorrhage by enhancing blood clotting at an opened wound using chitosan/polylactic acid/polycaprolactone wound dressing device

Doxycycline and monosodium glutamate (MSG) loaded chitosan (CHI)/polylactic acid (PLA)/polycaprolactone (PCL) blend film was studied as a model device to deliver drug to targeted human organ which in this case was the skin with opened wound. The CHI/PLA/PCL blend film containing 60 % CHI, 28 % PLA, and 12 % PCL exhibited the good properties for making the dressing device. It was observed that doxycycline/MSG loaded CHI/PLA/PCL blend film could rapidly deliver both doxycycline and MSG at the high release percentage approaching 100 % loaded. MSG accelerated blood clotting and fibrin formation; thus, it exhibited the good hemostatic activity. The antibacterial activity of doxycycline loaded CHI/PLA/PCL blend film against Staphylococcus aureus and Escherichia coli as model bacteria was investigated. Doxycycline release played the crucial role in bacterial inhibition as observed from the lowest bacterial cell dry weight observed when compared with the control bacterial culture or the bacterial cultures with the presence of other films studied.

In vitro study of the effects of plaunotol on oral cell proliferation and wound healing

Plaunotol is an acyclic diterpene alcohol extracted from a medicinal plant called plau-noi, Croton stellatopilosus Ohba, and has been widely used for the treatment of gastric ulcers in Japan. The aim of this study was to examine the effects of plaunotol on human gingival fibroblasts (HGFs) and human oral keratinocytes (HOKs). To assess the cytotoxic effect, HGFs and HOKs were treated with plaunotol. Subsequently, the morphology of cells was recorded and cells were subjected to MTT assay. To investigate cell proliferation effect, cells were treated with plaunotol and counted with a haemocytometer. To determine wound healing effect, the number of cells repopulated into the wounded areas in monolayer culture and in fibroblast-populated collagen lattice (FPCL) was measured. The results showed that 10 and 1 μg/ml (33 and 3.3 μmol/l) plaunotol induced toxicity in HGFs and HOKs, respectively. However, 0.1 μg/ml (0.33 μmol/l) plaunotol promoted HGF proliferation and wound healing in monolayer and FPCL models. In contrast, 0.1 μg/ml plaunotol could not induce HOK proliferation nor in vitro wound healing using monolayer culture, but it induced wound healing in a modified FPCL model. Our data suggested that plaunotol could promote oral cell proliferation and wound healing in vitro and may have an implication on oral wound healing.

Moluccensins H-J, 30-ketophragmalin limonoids from Xylocarpus moluccensis

Three new phragmalin limonoids, moluccensins H-J (1-3), were isolated from seed kernels of the cedar mangrove, Xylocarpus moluccensis. Their structures were established by extensive spectroscopic analysis. Compound 2 displayed weak antibacterial activity against Staphylococcus hominis and Enterococcus faecalis.

Hemagglutinating activity of proteins from Parkia speciosa seeds

Proteins from Parkia speciosa Hassk. (Fabaceae) seeds were extracted and stepwise precipitated using ammonium sulfate. Proteins precipitated with 25% ammonium sulfate were separated by affinity chromatography on Affi-Gel Blue gel followed by protein liquid chromatography on Superdex 200. The protein Gj, which was identified as a protein similar to putative aristolochene synthase, 3'-partial from Oryza sativa L. (Poaceae), had hemagglutinating activity of 0.39 mug/muL. Moreover, fraction C2 from the proteins precipitated with 60% ammonium sulfate, separated by lectin-specific adsorption chromatography using Con A Sepharose, had hemagglutinating activity of 1.17 mug/muL. Using gel electrophoresis, two proteins C2a and C2b were separated, having molecular weights of 45 kDa and 23 kDa, respectively. From protein identification, C2a was found to be similar to the hypothetical protein B1342F01.11 from Oryza sativa, and C2b was similar to the hypothetical protein At1g51560 from Arabidopsis thaliana (L.) Heynh. (Brassicaceae).

Protoxylocarpins F-H, protolimonoids from seed kernels of Xylocarpus granatum

Three new protolimonoids, protoxylocarpins F-H (1-3), along with 11 known limonoids, were isolated from seed kernels of Xylocarpus granatum. Their structures were elucidated on the basis of extensive spectroscopic data analyses. All compounds isolated were evaluated for cytotoxic activity against five human tumor cell lines.

3,3,6,6-Tetrakis-(hydroxy-meth-yl)-1,2,4,5-tetra-zinane tetra-hydrate

In the title compound, C(6)H(16)N(4)O(4)·4H(2)O, the tetra-zinane mol-ecule lies across an inversion centre. The tetra-zinane ring adopts a chair conformation, and all imino H atoms occupy axial positions. In the crystal, adjacent mol-ecules are linked through O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds with water mol-ecules generating a three-dimensional network.

Proximate analysis and physico-chemical properties of flour from the seeds of the China chestnut, Sterculia monosperma Ventenat

The aim of this study was to evaluate nutritional composition of China chestnut seeds, Sterculia monosperma Vent. and analyze the physico-chemical properties of flour from the seeds. The results obtained on proximate analysis of China chestnut seeds, S. monosperma, revealed that they contained mostly carbohydrate (73.7% dm), followed by fat (12.0% dm), protein (7.8% dm), fiber (5.5% dm) and ash (1.0% dm). They have a relatively high content of potassium (12.3 mg g(-1) dm) following by phosphorus (2.30 mg g(-1) dm), magnesium (1.87 mg g(-1) dm), sulfur (0.88 mg g(-1) dm) and calcium (0.14 mg g(-1) dm). The fatty acids profile was found to be composed of mainly palmitic (42%) and oleic acids (34%), with general long-chain fatty acids the other significant component by mass (13%). Glutamic acid (17.4%), aspartic acid (12.5%) and arginine (12.5%) were the three major amino acid constituents. The purified seed starch was investigated for its morphological, starch content and physico-chemical properties, such as amylose content, swelling power, solubility and pasting properties. The starch granules were quite round, about 10-15 micron diameter and composed of more than 35% (w/w) of amylose. The pasting properties of flour from the seeds of S. monosperma revealed that gelatinization began at 72.6-73.2 degrees C and the maximum viscosity in the holding period at 95 degrees C was 633 BU. Interestingly and potentially of use, was that the viscosity at the cooling period was more than two-fold higher than that in the holding period.

Quantitative thin layer chromatographic analysis of the saponins in tea seed meal

INTRODUCTION

The defatted seed meal of Camellia oleifera Abel., which contains saponins, is used extensively in aquaculture to eliminate unwanted fish and harmful insects during the cultivation of prawns, and as a molluscicide to control Pomacea canaliculata Lamarck. For the quality control of such tea seed meal products, a method for the determination of saponin content is required.

OBJECTIVE

To develop a simple, sensitive and specific method for the quantitative determination of saponins in tea seed meal using high-performance thin layer chromatography and densitometry.

METHODOLOGY

Powdered tea seed meal samples were extracted with methanol, filtered, evaporated to dryness and the residue taken up in methanol. Samples, together with methanolic solutions of saponin standard, were analysed by HPTLC on silica gel layers eluted with ethyl acetate:methanol:water (6:3:1.5, v/v/v) and detected at 214 nm. The amounts of saponins were determined from the respective calibration curves obtained by plotting the concentrations of saponin standard against peak area.

RESULTS

Tea saponin peaks were detected at about R(f )0.40. Good linearity was observed in the range of 0.9-22.2 microg/spot with a correlation coefficient of 0.9978. The limits of detection and quantification were 0.87 and 2.90 microg/spot, respectively. The content of tea saponins in 10 tested samples was found to be between 13.1 and 21.1% w/w.

CONCLUSION

The assay proved to be a specific, sensitive and inexpensive method for the quality control of saponins in tea seed meal.

A new sesquiterpenoid metabolite from Psilocybe samuiensis

A novel 2,3-secoaromadendrane-type sesquiterpenoid metabolite, psilosamuiensin A (1), was isolated from the broth of Psilocybe samuiensis. The structure of psilosamuiensin A was established by spectroscopic data and its configurations were confirmed by single crystal X-ray crystallographic analysis. This is the first report of psilosamuiensin A found in the genus Psilocybes.

Neutralization of lethality and proteolytic activities of Malayan pit viper (Calloselasma rhodostoma) venom with North American Virginia opossum (Didelphis virginiana) serum

Malayan pit viper (Calloselasma rhodostoma) envenomation is a major health problem in South East Asia. During envenomation, venom components mainly affect the hemostatic system. The sera from the North American Virginia opossums (Didelphis virginiana) were able to neutralize the venom of the Malayan pit viper. These natural inhibitors could be explored as potential therapeutics against envenomations of a variety of venomous snake species in different geographical habitats.

Microemulsion electrokinetic chromatography for separation and analysis of curcuminoids in turmeric samples

Microemulsion EKC (MEEKC) was developed for quantitative analysis of curcuminoids, such as curcumin (C), demethoxycurcumin (D), and bis-demethoxycurcumin (B). MEEKC separation of curcuminoids was optimized, and a change in resolution was explained using a modified equation for resolution in MEEKC without electroosmosis. The suitable MEEKC conditions for separation of curcuminoids were obtained to be the microemulsion buffer containing 50 mM phosphate buffer at pH 2.5, 1.1% v/v n-octane as oil droplets, 180 mM SDS as surfactant, 890 mM 1-butanol as cosurfactant, and 25% v/v 2-propanol as organic cosolvent; applied voltage of -15 kV; and separation temperature 25 degrees C. Achieved baseline resolution of C:D and D:B was obtained with R(s) -2.4 and analysis time within 18 min. In addition, high accuracy and precision of the method were obtained. This MEEKC method was used for quantitative determination of individual curcuminoids in medicinal turmeric capsules and powdered turmeric used as coloring additive in food, with simple sample preparation such as solvent extraction, dilution, and filtration, and without cleaning up by SPE.

Antimalarial benzoquinones from an endophytic fungus, Xylaria sp

Two novel benzoquinone metabolites, 2-chloro-5-methoxy-3-methylcyclohexa-2,5-diene-1,4-dione ( 1) and xylariaquinone A ( 2) together with two known compounds were isolated from an endophytic fungus, Xylaria sp. Their structures were assigned by analysis of spectroscopic data, and the structures of 1 and 3 were also confirmed by single-crystal X-ray data. Compounds 1 and 2 showed in vitro activity against Plasmodium falciparum, K1 strain, with IC 50 values of 1.84 and 6.68 microM and cytotoxicity against African green monkey kidney fibroblasts (Vero cells) with IC 50 values of 1.35 and >184 microM, respectively.

Cassane furanoditerpenoids from the seed kernels of Caesalpinia bonduc from Thailand

Three new cassane furanoditerpenoids ( 1- 3), together with 13 known cassane diterpenes ( 4- 16), were isolated from the EtOAc extract of the seed kernels of Caesalpinia bonduc. Their structures were elucidated on the basis of spectroscopic analysis, mainly NMR and MS. Compounds 1- 3 exhibited good antimalarial activity against the multidrug-resistant K1 strain of Plasmodium falciparum, while compound 4 was inactive. None of the compounds were cytotoxic against any of the tumor cell lines tested.

Purification and biochemical characterization of an extracellular β-glucosidase from the wood-decaying fungusDaldinia eschscholzii(Ehrenb.:Fr.) Rehm

An extracellular beta-glucosidase was purified from culture filtrates of the wood-decaying fungus Daldinia eschscholzii (Ehrenb.:Fr.) Rehm grown on 1.0% (w/v) carboxymethyl-cellulose using ammonium sulfate precipitation, ion-exchange, hydrophobic interaction and gel filtration chromatography. The enzyme is monomeric with a molecular weight of 64.2 kDa as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and has a pI of 8.55. The enzyme catalyzes the hydrolysis of p-nitrophenyl-beta-D-glucopyranoside (PNPG) as the substrate, with a K(m) of 1.52 mM, and V(max) of 3.21 U min mg(-1) protein. Glucose competitively inhibited beta-glucosidase with a K(i) value of 0.79 mM. Optimal activity with PNPG as the substrate was at pH 5.0 and 50 degrees C. The enzyme was stable at pH 5.0 at temperatures up to 50 degrees C. The purified beta-glucosidase was active against PNPG, cellobiose, sophorose, laminaribiose and gentiobiose, but did not hydrolyze lactose, sucrose, Avicel or o-nitrophenyl-beta-d-galactopyranoside. The activity of beta-glucosidase was stimulated by Ca(2+), Co(2+), Mg(2+), Mn(2+), glycerol, dimethyl sulfoxide (DMSO), dithiothreitol and EDTA, and strongly inhibited by Hg(2+). The internal amino acid sequences of D. eschscholziibeta-glucosidase have similarity to the sequences of the family 3 beta-glucosyl hydrolase.

Furanocembranoids from the stem bark of Croton oblongifolius

Four novel furanocembranoids (1-4) were isolated from the stem bark of Croton oblongifolius. Their structures were elucidated on the basis of spectroscopic analysis, mainly NMR and MS. Compounds 1, 3, and 4 exhibited good cytotoxicity against several human tumor cell lines.

Retention factor and retention index of homologous series compounds in microemulsion electrokinetic chromatography employing suppressed electroosmosis

The retention factor (k) and retention index (I) of homologous series compounds such as alkylbenzenes (BZ), alkylaryl ketones, alkylbenzoates, and alkylparabens in microemulsion electrokinetic chromatography (MEEKC) with suppressed electroosmosis were investigated in a wide range of SDS concentrations ([SDS]), temperatures, and concentrations of organic cosolvents (phi). Using BZ as standards, the retention indices of other homologous series compounds were determined and they were found to be independent of [SDS] and temperature, while are dependent on the types and concentrations of organic cosolvents. The retention factor linearly increases with increasing [SDS], while linearly decreases with increasing temperature. The value of log k linearly decreases with increasing phi for methanol, ethanol, or ACN, while decreases by a second-degree polynomial with increasing phi for 2-propanol. Excellent agreement was found between the observed and predicted values of log k of analytes in MEEKC at given [SDS] and phi, where the predicted values were obtained from modified equations of the linear relationship of log k as functions of [SDS], the number of carbons, and phi. Therefore, both k and I can be used for peak identification of homologous series compounds.

Cytotoxic constituents from Butea superba Roxb

A carpin (3-hydroxy-9-methoxypterocarpan) (Medicarpin) (1) and four isoflavones, 7-hydroxy-4'-methoxy-isoflavone (Formononetin) (2); 7,4'-dimethoxyisoflavone (3); 5,4'-dihydroxy-7-methoxy-isoflavone (Prunetin) (4) and 7-hydroxy-6,4'-dimethoxyisoflavone (5) were isolated from the tuber roots of Butea superba Roxb. Compounds 2 and 4 showed moderate cytotoxic activity on KB cell lines with IC(50) (microM) values of 37.3+/-2.5 and 71.1+/-0.8 and on BC cell lines with IC(50) (microM) values of 32.7+/-1.5 and 47.3+/-0.3, respectively.