Bioassay-guided isolation of urease and α-chymotrypsin inhibitory constituents from the stems of Lawsonia alba Lam. (Henna)

Seven constituents were isolated from the stems of Lawsonia alba Lam., following an activity-guided isolation, which include two new constituents, namely lawsorosemarinol (1) and lawsofructose (2), one known compound 2-(β-d-glucopyranosyloxy)-1, 4-naphthoquinone (3) and four compounds, 4-hydroxy coumarine (4), 3-(4-hyroxyphenyl)-triacontyl-(Z)-propenoate (5), 3-(4-hydroxy-3-methoxyphenyl)-triacontyl-(Z)-propenoate (6) and 7-hydroxy-4-methyl coumarin (7) first time isolated from Lawsonia alba. Their structure elucidation was based on spectroscopic data analyses. Compounds 3 and 7 showed a moderate inhibition of urease activity, while rest of them showed less than 50% inhibition. These compounds did not show any significant inhibition against α-chymotrypsin.     

Triterpenoids and α-glucosidase inhibitory constituents from Salacia hainanensis

Thirteen triterpenoids (1–13), including two new lupane triterpenoids, salacinins A and B (1 and 2), as well as one new friedelane triterpenoid, salacinin C (3), were isolated from the roots and stems of Salacia hainanensis. The structures of new compounds were elucidated by extensive spectroscopic analysis including 1D and 2D NMR, and MS experiments. Compound 1 possesses rare 2,3-seco-lupane skeleton. Compounds 4, 6 and 7 showed inhibitory effects on α-glucosidase in vitro.     

Chemical structures and thermochemical properties of bagasse lignin

1 Introduction Agricultural residues are an important renewable bio- mass resource. The annual production is more than 600 million tons in China. With the reduction of fossil fuel resources, the new trend is to acquire chemicals and energy from renewable resources. To produce green chemicals and clean fuels by developing bio- mass, biorefinery technology is one of the more promising technologies and objectives. Bagasse consists of cellulose, hemicellulose and lignin. Earlier studies have sho…     

The essential oil of Eucalyptus tereticornis, and its constituents α- and β-pinene,potentiate acetylcholine-induced contractions in isolated rat trachea

The effects of the essential oil of Eucalyptus tereticornis (EOET), especially the effects of its constituents α- and β-pinene, were studied on rat trachea in vitro. In tracheal rings, EOET, α- or β-pinene potentiated the contractions induced by acetylcholine (ACh). Contractions induced by K⁺ (60 mM) were also potentiated by α- and β-pinene, but were reduced by EOET. Our findings show that EOET has myorelaxant effects on rat airways, but potentiates ACh-induced contractions. Monoterpenes α- and β-pinene are involved in its potentiating actions, but are not responsible for its myorelaxant effects. A putative inhibition of the acetylcholinesterase enzyme is involved.     

Two new α-pinene derivatives from Angelica sinensis and their anticoagulative activities

Two new α-pinene derivatives (1-2) were isolated from the aerial parts of Angelica sinensis. Their structures were determined by spectroscopic and chemical methods to be 6β,9-dihydroxy-(+)-α-pinene (1) and 9-hydroxy-(+)-α-pinene-6β-O-D-glucoside (2). In the anticoagulative assay, compounds 1 and 2 exhibited weak antithrombin activity and strong antiplatelet aggregation activity in vitro.     

Iridoid and phenylpropanoid glycosides from Scrophularia ningpoensis Hemsl. and their α-Glucosidase inhibitory activities

A new phenylpropanoid glycoside, designated Scrophuside (1) and two new iridoid glycosides, respectively named Ningposide I (2) and Ningposide II (3), along with twelve known (4–15) iridoid and phenylpropanoid glycosides were obtained from the roots of Scrophularia ningpoensis Hemsl. by various chromatographic techniques and their structures were established through chemical methods and spectroscopic analyses. Most of the obtained compounds have been screened for α-Glucosidase inhibitory activity, in which compounds 4, 5, 7, 11, 12, 13, and 14 show significant activity.     

Study on Chemical Components and Properties of Radial Chinese Fir

The variability of main chemical composition of radial Chinese fir was studied. Analysis of variance showed that variance was significant, especially for holocellulose and α-celluloSe; the hblocellulose content in heart wood was lower than that in sapwood; the lignin content decreased from Position t to Position 3, but increased gradually from Position 4 to Position 8; the a ~ cellulose content in heart wood was lower than that in sapwood; and the relative crystallinity was 59.97% in Position 1, 60i80% in Position 2, and about 42% in others.     

Anti-acetylcholinesterase, anti-α-glucosidase, anti-leishmanial and anti-fungal activities of chemical constituents of Beilschmiedia species

Phytochemical investigation of Beilschmiedia alloiophylla has resulted in the isolation of one new alkaloid, 2-hydroxy-9-methoxyaporphine (1), and ten known natural products, laurotetanine (2), liriodenine (3), boldine (4), secoboldine (5), isoboldine (6), asimilobine (7), oreobeiline (8), 6-epioreobeiline (9), β-amyrone (10), and (S)-3-methoxynordomesticine (11). Chemical studies on the bark of B. kunstleri afforded compounds 2 and 4 along with one bisbenzylisoquinoline alkaloid, N-dimethylphyllocryptine (12). Structures of compounds 1-12 were elucidated on the basis of spectroscopic methods. All of these isolates were evaluated for their anti-acetylcholinesterase (AChE), anti-α-glucosidase, anti-leishmanial and anti-fungal activities. Compounds 1-12 exhibited strong to moderate bioactivities in aforementioned bioassays.     

Role of Trees in Urban Areas and Challenges of their Establishment

1 INTRODUCTIONThe urban landscapes expand over large area. Asurbanization spreads into less developed rural areas, agrowing percentage of the natural resources will becomea part of urban forest ecosystems, and increasingamounts of forest outside these systems also will besubject to urban influence.The expansion of urban landscapes has particularlyimportant implications for the use and management ofpublic holdings, including protected forests, nationalparks, and state and locally administer…     

Caffeoylquinic acid derivatives isolated from the aerial parts of Gynura divaricata and their yeast α-glucosidase and PTP1B inhibitory activity

The phytochemical investigation of natural products of Gynura divaricata led to the isolation of eleven caffeoylquinic acid derivatives. They were characterized by spectrometric methods as 5-O-caffeoylquinic acid (1), 5-O-p-coumaroylquinic acid (2), 5-O-feruloylquinic acid (3), methyl 5-O-caffeoylquinate (4), 3,4-dicaffeoylquinic acid (5), 3,5-dicaffeoylquinic acid (6), 4,5-dicaffeoylquinic acid (7), methyl 3,4-dicaffeoylquinate (8), methyl 3,5-dicaffeoylquinate (9), methyl 4,5-dicaffeoylquinate (10) and ethyl 4,5-dicaffeoylquinate (11). The individual compounds were screened for the inhibition of yeast α-glucosidase and Protein Tyrosine Phosphatase 1B (PTP1B) using in vitro assays. Among the isolated compounds, 3,4-dicaffeoylquinic acid (5), 4,5-dicaffeoylquinic acid (7), methyl 3,4-dicaffeoylquinate (8) and methyl 4,5-dicaffeoylquinate (10) exhibited significant inhibitory activities against α-glucosidase. In addition, 5-O-p-coumaroylquinic acid (2), 3,5-dicaffeoylquinic acid (6) and 4,5-dicaffeoylquinic acid (7) had considerable inhibitory effect against PTP1B. Based on these findings, the caffeoylquinic acid derivatives were deduced to be potentially responsible for the anti-diabetic activity of G. divaricata. The preliminary structure–activity relationship study suggests that the number and positioning of caffeoyl groups in the quinic acid derivatives are important for both α-glucosidase and PTP1B inhibitory potency. Moreover, the corresponding methyl esters of some dicaffeoylquinic acids have enhanced inhibitory activity against yeast α-glucosidase.     

Structural Change of Wood Molecules and Chemorheological Behaviors during Chemical Treatment

It is very important to clarify the relationship of changes of molecular combinations in wood cell walls and the chemical rheological behavior during various chemical reagent treatments, for it would be helpful to develop new wood modification technologies and to enrich the theory of chemical rheology of wood. Based on previous investigations on the chemorheological properties of wood by chemical treatments and the applied methods in chemical rheology of wool fibers, this paper proposes thestudy of various additional reagents to wood saturated in water for long periods of time in order to investigate the chemical theology of wood, which can provide information about the character of combinations between wood molecules and the structural changes of molecules and further put forward the idea of modifying wood in a decrystallized state.     

Correlation between Chemical Structure and Biological Activity of Host-Selective Plant Pathogen Mycotoxins

Toxin, one of the most important factors of plant fungal disease, has attracted much attention of many academicians who have been studying pathogen mycotoxin in deep research. The paper summarized chemical structures of some host-selective plant pathogen mycotoxins discovered in recent years and the correlation between biological activity and chemical structure of toxin.     

A Study on Chemical Compositions and Fiber Characteristics of Two Sympodial Bamboos

The chemical composition and fiber characteristics of two sympodial bamboos have been studied in this paper. Based on analysis results, it is shown that the Whangee (D. Membranaceus Munro) bamboo is better than Yunnanicus bamboo(D. yunnaicus Hsueh et D. Z. Li) in utilization because of its higher specific gravity, better fiber length and its distribution rule and higher wall/lumen ratio, and that the Whangee bamboo is more suitable for papermaking and panel processing used in house construction. In addition, the higher benzene-ethanol extractives of the Whangee bamboo can be an advantage for anti-decay in architecture processing and utilization compared with the Yunnanicus bamboo.     

Kaurane-type diterpenoids from Chromoleana odorata, their X-ray diffraction studies and potent α-glucosidase inhibition of 16-kauren-19-oic acid

A new diterpenoid, 15-angeloyloxy-16,17-epoxy-19-kauronic acid (1), along with five known metabolites, 16-kauren-19-oic acid (2), 6′-hydroxy-2′,3′,4,4′-tetramethoxychalcone (3), isosakuranetin (4), acacetin (5), and kaempferide (6) was isolated from the organic extracts of the roots of Chromoleana odorata. Their structures were determined by spectroscopic evidences. The structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction studies. Compound 2 exhibited significant α-glucosidase inhibitory and antibacterial activities against Escherichia coli and Bacillus subtilis.     

Comparative Study in Chemical Character and Fatty acid Compositions of Masked Civet''''s Fat and Nutria''''s Oil

IntroductionMaskedciVet(Paguma18vata),Mammalia,Viverridae,ismainlydiStributedinShanxi,Sichuan,Tibet,Yunnanprovinces,etc..Itsmeatisdeliciousandhasspecialflavor.Itiseasytoberaisedartificially,withhighproduCtivity.Nutria(MyocasterCOypus),Rodentia,Capromyidae,originatedinArgentina,Chili,etc.insouthAmerica.Itisakindofherbivoresfur-bearer.itsartificialraisinghassuchmeritsasdurablefurandlowcostandhighproduCtivity.MaskedcivetandnutriahavehigheconomicvalueandwideprospeCtofutilization.Atpresen…     

Preparation of liquefied wood-based resins and their application in molding material

To investigate value in use of liquefied wood-based resin applications in molding material, Chinese fir （Cunninghamia lanceolata） and poplar （Populus tomentosa） wood meal were liquefied in phenol. The reactant was co-condensed with formaldehyde to obtain liquefied wood-based resin. For this paper, we investigated the characterization of the resin and its application in molding material. The result shows that the basic properties of liquefied wood-based resin were satisfactory; the bonding strength of plywood prepared with liquefied Chinese fir and liquefied poplar resin can reach 1.54 and 1.00 MPa, respectively. The compression strengths of the molding material prepared with two kinds of liquefied wood resin were 73.01 and 73.58 MPa, almost the same as that of PF resin molding material. The limiting volume swelling of molding material made with liquefied Chinese resin and liquefied poplar resin were 8.5% and 8.3%, thickness swelling rates of water absorption were 3.3% and 4.2%, and the maximum weight ratios of water absorption were 25.9% and 26.2%, respectively. The soil burial test result shows that the weight loss rate of the molding materials made with liquefied Chinese resin and liquefied poplar resin were 8.3% and 9.1% and that of the PF resin molding material was 7.9%. After the soil internment test, the reduction ratio of compression strength of the two kinds of molding material achieved 16.9% and 17.7%, while that of the PF resin molding material was 15.4%. The test results of wood fungi inoculation on the three surfaces of the molding material indicate the breeding rate of molding material prepared with liquefied Chinese resin and liquefied poplar resin were at level 4 and that of PF resin molding material was at level 1 of the ISO standard.     

Chemical composition and free radicals restraining activity of extracts from three Manglietia species leaves

The extracts from leaves of Manglietia insignis （Wall） Blume, Manglietia chingii Dandy and Manglietia yuyuanensis Law were prepared by organic solvent extraction and their components were analyzed by GC/MS and quantified. Meanwhile, the free radicals restraining activities were detected. The 21 compounds in M. insignis, 36 compounds in M. chigii and 20 compounds in M. yuyuanensis were identified. There were 11 common components in the extracts from three Manglietia species, and 12 components in two Manglietia species. The results of relative contents of every component in three extracts showed that the main constituents of M. insignis were terpenoids and alkene, amounting to 38.93%, followed by alkane （28.18%）, the nitrogen containing compounds （15.73%） and aromatic compounds （7.23 %）. The main constituents of leaf extract from M. chingii were the terpenoids and alkene, carboxylic acid, alkane and aromatic compounds, amounting to 30.22%, 14.17%, 13.87% and 13.29%, respectively, The main constituents of M. yuyuanensis were alcohol compounds, the terpenoids and alkene, and aromatic compounds, amounting to 28.00%, 25.38% and 18.00% respectively. The results showed that the three extracts had strong function of restraining oxygen free radicals. The ultra oxygen anions activity was restrained at the highest level, when the three extracts were diluted by hundred-fold, whereas the restraining capacity of hydroxyl free radicals reached maximum, when the three extracts were diluted by twenty-fold. The above results provide scientific evidences for further approaching the ecological healthy function of three MangUetia species     

Chemical modification of simul wood with styrene–acrylonitrile copolymer and organically modified nanoclay

Simul wood (Salmalia malabarica) was chemically modified by treatment with styrene–acrylonitrile copolymer (SAN), glycidyl methacrylate (GMA), and organically modified nanoclay. The physical properties of wood polymer composites (WPC) were improved due to the addition of GMA and nanoclay. XRD analysis indicated a decrease in crystallinity in WPC. FTIR study confirmed the presence of clay in WPC. The presence of clay in cell lumen and cell wall was evidenced by SEM study. WPC containing lower percentage of clay showed better thermal stability compared to WPC loaded with higher percentage of clay.     

Proton spin–lattice relaxation time measurements of solid wood and its constituents as a function of pH: Part I*

Summary  By measuring the proton spin–lattice relaxation times (T_1H) in the solid-state for black spruce softwood, the molecular mobilities of carbohydrates and lignin have been evaluated as a function of pH. These studies have shown that the mobility of the polymeric constituents of wood is affected by the ionization of the different functional groups at different pH's. The analyses of the proton-spin–lattice relaxation time data at constant humidity revealed that the maximum T_1H for both carbohydrates and lignin occurs at about neutrality, while it was found to be depressed at the two extremes of the pH range. By treating a wood sample with propylene oxide, the esterification of the acid groups was affected, thus deactivating the ionization process and their contribution to T_1H. The experimental T_1H values for cellulose and lignin after the esterification were significantly decreased at pH 6 confirming that their ionization plays a very significant role in determining chain mobility. Received 1 December 1998