Two new sterols, 3 beta, 7 alpha, 16 beta -trihydroxy-stigmast-5,22-diene (1), 3 beta, 7 alpha, 16 beta -trihydroxy-stigmast-5-ene (2), were isolated together with six known compounds, ergosta-5, 24(28)-dien-3 beta, 7...Two new sterols, 3 beta, 7 alpha, 16 beta -trihydroxy-stigmast-5,22-diene (1), 3 beta, 7 alpha, 16 beta -trihydroxy-stigmast-5-ene (2), were isolated together with six known compounds, ergosta-5, 24(28)-dien-3 beta, 7 alpha -diol (3), ergosta-5,24(28)-dien-3 beta, 7 beta, 16 beta -triol (4), beta -amyrone (5), beta -amyrin (6), 11 alpha, 12 alpha -epoxy-14-taraxeren-3-one (7), and 6-guaiene-4 alpha, 10 alpha -diol (8) from the EtOH extract of the bark of Amoora yunnanensis (H. L. Li) C. Y. Wu. Their structures were deduced on the basis of spectral data.展开更多
The chemical constituents, pharmacological activity and traditional uses of 20 species attributed to the genus Elsholtzia (Labiatae) used in China are reviewed and compared. A survey of the literature available show...The chemical constituents, pharmacological activity and traditional uses of 20 species attributed to the genus Elsholtzia (Labiatae) used in China are reviewed and compared. A survey of the literature available shows that these species are used mostly for the treatment of respiratory and gastrointestinal disorders. Additionally, some of these Elsholtzia species show antibacterial, anti-inflammatory, relieving fever, analgesic activities and myocardial ischemia protection. Generally, the essential oils or flavonoids from these plant extracts are assumed to be the active principles.展开更多
Aim To investigate novel bioactive and structural metabolites from marineorganisms. Methods Column chromatography in association with semi-preparative HPLC were used for theisolation of compounds. 1D and 2D NMR, IR, U...Aim To investigate novel bioactive and structural metabolites from marineorganisms. Methods Column chromatography in association with semi-preparative HPLC were used for theisolation of compounds. 1D and 2D NMR, IR, UV, and MS were employed for structure elucidation.Results From the butanol fraction of the 95% EtOH extract of the starfish Asterias rollestoni, a newcompound N^7 -2'-deoxypseudoxanthosine (1), along with sixteen known compounds, 2'-0-methyl-inosine(2), 2'-deoxyinosine (3), 2'-0-methylguanosine (4), inosine (5); thymine (6), uracil (7), thymidine(8), deoxyuridine (9), 2'-0-methyluridine (10), ( ― )-(1S, 3S)-1-methyl-1, 2, 3,4-terrahydro-β-carboline-3-carboxyl-ic acid (11), ( ― )-(1R, 3S)-1-methyl-1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (12) , ( ― )-(3S)- 1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (13), L-tryptophan (14), L-phenylalanine (15), 3-carboxyindole (16), and p-hydroxybenzoic acid (17) , have been isolated. Conclusion Compound 1 is a newnatural product, and compounds 8, 9 and 10 are isolated from natural sources for the first time, andthe known compounds except 14 and 15 are first reported from starfish Asterias rollestoni.展开更多
[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by...[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by determination of the contents of four cell wall materials, six routine chemical components, as well as aroma constituents. [Result] Pectinase could effectively reduce the contents of cell wall materials in tobacco stems, with the largest decrease of 6.84%; after pectinase treatment,the content of reducing sugar in tobacco stems increased obviously, and the contents of total sugar, potassium ion, chloride ion and total nitrogen increased to varying degrees, of which the contents of potassium ion and reducing sugar displayed upward trends with the increase of pectinase concentration. Pectinase treatment significantly increased the contents of Maillard reaction products, with the most increase of 67.2%;the contents of carotenoid degradation products, phenylalanine degradation products and neophytadiene all increased to varying extents, and the contents of both Maillard reaction products and phenylalanine degradation products revealed ascending trends with the increase of pectinase concentration. [Conclusion] Pectinase treatment can effectively decompose cell wall materials in tobacco stems, improve routine chemical constituents, and increase the contents of aroma constituents.展开更多
In 2000 and 2001, 1-year-old seedlings of 7 economic tree species including chestnut, apricot, persimmon, peach, walnut, pear and apple were cultured in garden pots that had a diameter of 40 cm and were filled with cl...In 2000 and 2001, 1-year-old seedlings of 7 economic tree species including chestnut, apricot, persimmon, peach, walnut, pear and apple were cultured in garden pots that had a diameter of 40 cm and were filled with clean sand. The major components of exudates released from their roots were isolated and analysed by GC-MS. Totally 200 kinds of organic chemicals were isolated, of which 3 kinds i.e. naphthalene, dimethylbenzene and dibutyl phthalate were principally controlled pollutants according to 'Blacklist of Principal Environment Pollutants in China' and the standard of U.S. Environmental Protection Agency (EPA). The research result provided theoretical evidence for selecting low-pollution economic forest crops in the water source protection area in Miyun Reservoir.展开更多
Four diterpenoids, including a new ent-kaurane diterpene (1), were isolated from the rhizome of Aralia fargesii Franch. On the basis of chemical and spectral evidence (IR, EI-MS, HREI-MS, H-1-NMR, C-13-NMR and HMQC), ...Four diterpenoids, including a new ent-kaurane diterpene (1), were isolated from the rhizome of Aralia fargesii Franch. On the basis of chemical and spectral evidence (IR, EI-MS, HREI-MS, H-1-NMR, C-13-NMR and HMQC), the structure of compound 1 was established to be 17-acetoxy-16alpha-ent-kauran-19-oic acid The other three known compounds were identified as ent-pimera-8(14) 15-dien-19-oic acid (2), 16alpha-hydroxy-( -)-kauran-19-oic acid (3) and 16alpha-17-dihydroxy-ent-kauran-19-oic acid (4). The three known diterpenoids were obtained from this plant for the first time.展开更多
Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosi...Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosin-7-0-(3-D-glucopyranoside) were isolated from the roots of Astragalus mem-branaceus (Fisch.) Bunge. Their structures were established by spectral analysis.展开更多
Through field experiment,special biological fertilizer and cake fertilizer were applied collectively to tobacco,and chemical compositions of Wanxi flue-cured tobacco leaves were researched.The results showed that the ...Through field experiment,special biological fertilizer and cake fertilizer were applied collectively to tobacco,and chemical compositions of Wanxi flue-cured tobacco leaves were researched.The results showed that the increase of biological organic fertilizer would significantly improve soil nutrient supplying capacity.Compared with conventional fertilization,the contents of reducing sugar,total sugar and starch in different parts of tobaccos which were applied with biological organic fertilizer were closer to standards of excellent tobacco.In the treatment,the ratio of reducing sugar and nicotine in tobacco was more suitable in middle and lower parts of the plant and the contents of total N,nicotine and chlorine in tobacco were lowered,improving tobacco quality.展开更多
[Objective] This study aimed to investigate the differences in chemical composition of supercritical CO2 extraction products in peels of Trichosanthes kirilowii Maxim. from Changqing district. [Method] Supercritical f...[Objective] This study aimed to investigate the differences in chemical composition of supercritical CO2 extraction products in peels of Trichosanthes kirilowii Maxim. from Changqing district. [Method] Supercritical fluidextraction (SFE) and GCMS method were applied to determine and analyze the chemical components of the extracts in peels of three strains of Trichosanthes kirilowii Maxim. [Result] The chemical components of supercritical CO2 extraction products in peels of three strains of Trichosanthes kirilowii Maxim. varied., and the number of chemical components with normalized percentage content higher than 1% was 5, 7 and 8, respectively. There are 14 kinds of common components, and the relative content of hexadecanoic acid was the highest. [Conclusion] Supercritical CO2 extracts in peels of different strains of Trichosanthes kirilowii Maxim. contain different chemical components, providing scientific basis for breeding excellent varieties and the development and utilization of Trichosanthes kirilowii Maxim.展开更多
The phase equilibria and compositions in Mg-rich side at 300 ℃ were investigated in Mg-Zn-Ca ternary system through the equilibrated alloy method by using scanning electron microscopy,electron probe microanalysis,X-r...The phase equilibria and compositions in Mg-rich side at 300 ℃ were investigated in Mg-Zn-Ca ternary system through the equilibrated alloy method by using scanning electron microscopy,electron probe microanalysis,X-ray diffraction and transmission electron microscopy.The results show that two ternary compounds T1 and T2 can be in equilibrium with the Mg-based solid solution in Mg-Zn-Ca system.T1 phase is a linear compound with the composition region(molar fraction) of 15% Ca,20.5%-48.9% Zn and balanced Mg at 300 ℃.Its hexagonal structure parameters decrease with increasing Zn content,i.e.a=0.992-0.945 nm,c=1.034-1.003 nm.T2 phase has hexagonal structure with the composition region of 26.4%-28.4% Mg,63.2%-65.5% Zn and 7.1%-8.4% Ca.At 300 ℃,the solubility of Zn in the Mg-based solid solution increases for the addition of Ca,the maximum solubility of Zn is 3.7%.Three-phase fields consisting of--Mg+Mg2Ca+T1,--Mg+T1+T2,--Mg+T2+MgZn and MgZn+T2+Mg2Zn3 exist in the Mg-Zn-Ca system at 300 ℃.展开更多
Two novel compounds, clemaphenol A and dihydro-4-hydroxy-5-hyroxymethyl-2(3H)-fura-none were isolated together with eight known compounds, isoferulic acid, b-sitosterol, daucosterol, 5-hy-droxymethyl-2-furancarboxalde...Two novel compounds, clemaphenol A and dihydro-4-hydroxy-5-hyroxymethyl-2(3H)-fura-none were isolated together with eight known compounds, isoferulic acid, b-sitosterol, daucosterol, 5-hy-droxymethyl-2-furancarboxaldehyde, 5-hydroxy-4-oxo-pentanoic acid, palmitic acid, linoleic acid and anemonin from the root of Clematis chinensis Osbeck.展开更多
Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergo...Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergosta-7,22-diene-3,6-dione (2) respectively on the basis of spectral analyses and physical and chemical identifications. Compound 1 was a new natural product. Compound 2 was firstly isolated from its genus. Spectral data of 1 and complete 1H NMR data of 2 were reported for the first time.展开更多
Aim Isolation and structural elucidation of the constituents from the aerialpart of Hypericum perforatum L. Methods Column chromatography and TLC were used to isolate chemicalconstituents. Physico-chemical characteriz...Aim Isolation and structural elucidation of the constituents from the aerialpart of Hypericum perforatum L. Methods Column chromatography and TLC were used to isolate chemicalconstituents. Physico-chemical characterization and spectroscopic analysis were employed forstructural identification. Results Three flavonols were isolated and identified. Conclusion Compound1 is a novel natural product and its structure has been characterized to be 3, 5, 7-trihydroxy-3',4'-isopropyldioxy-flavone.展开更多
The forms of phosphorus and silicon in the natural grain sizes surface sediments of the southern Bohai Sea were studied. In sediments, the organic matter bound form of phosphorus was the main form of transferable phos...The forms of phosphorus and silicon in the natural grain sizes surface sediments of the southern Bohai Sea were studied. In sediments, the organic matter bound form of phosphorus was the main form of transferable phosphorus and ranged from 0.37 μmol/g to 1.57 μmol/g, accounting for 10.7% of the total phosphorus, others were the carbonate bound form, iron manganese oxide bound form and ion exchange able form; the transferable form of phosphorus accounted for 19.2% of the total phosphorus. Silicon’s carbonate bound form was predominant over others among its transferable forms, and content ranged from 1.55 μmol/g to 8.94 μmol/g, accounting for 0.05% of the total silicon; the total amount of transferable silicon forms accounted for only 0.12% of the total silicon. Therefore, 19.2% of the total phosphorus and 0.12% of the total silicon contained in the surface sediments of the southern Bohai Sea could participate in the biogeochemical cycling.展开更多
Two procedures were compared for extraction and clean-up of 20organophosphorus and 19 pyrethroid pesticides in sediment to identify the more effective procedurefor groups of pesticides or individual compounds. In Proc...Two procedures were compared for extraction and clean-up of 20organophosphorus and 19 pyrethroid pesticides in sediment to identify the more effective procedurefor groups of pesticides or individual compounds. In Procedure I, methanol/water and n-hexane wereused for extraction, and 1:10 (v/v) dichloromethane in n-hexane and acetone were used as eluents foreluting the analyte through the cartridge, with one evaporating steps on a rotary evaporator andtwo eluting steps on the cartridge. n-hexane/acetone (2:1, v/v) was used for extraction and elutionin Procedure II with one evaporating step on a rotary evaporator and one eluting step on thecartridge. All extractions were performed under an ultrasonic bath and gas chromatography and massspectrometry were utilized for measurements. Procedure II was developed as a rapid, timesaving, lesscostly and safer substitute for Procedure I which was an old method. Procedure II was moreeffective for almost all the organophosphorus pesticides tested and 11of the 19 pyrethroidpesticides, while Procedure I was more appropriate for analysis of 5 pyrethroid pesticides. However,recoveries of most pyrethroid pesticides were fairly low. Thus, further studies should focus onadjustment and formulation of solvents for more efficient extraction and clean-up of pyrethroidpesticides from sediment samples.展开更多
Chemical composition of Gongronema latifolium leaves was determined using standard methods. Aqueous and methanol G. latifolium extracts were tested against thirteen pathogenic bacterial isolates. Crude protein, lipid ...Chemical composition of Gongronema latifolium leaves was determined using standard methods. Aqueous and methanol G. latifolium extracts were tested against thirteen pathogenic bacterial isolates. Crude protein, lipid extract, ash, crude fibre and nitrogen flee extractives obtained are: 27.2%, 6.07%, 11.6%, 10.8% and 44.3% dry matter respectively. Potassium, sodium, calcium, phosphorus and cobalt contents are 332, 110, 115, 125 and 116 mg/kg respectively. Dominant essential amino acids are leucine, valine and phenylalanine. Aspartic acid, glutamic acid and glycine are 13.8%, 11,9% and 10.3% respectively of total amino acid. Saturated and unsaturated fatty acids are 50.2% and 39.4% of the oil respectively. Palmitic acid makes up 36% of the total fatty acid. Extracts show no activity against E. faecalis, Y. enterolytica, E. aerogenes, B. cereus and E. agglomerans. Methanol extracts were active against S, enteritidis, S. cholerasius ser typhimurium and P. aeruginosa (minimum inhibitory concentration (MIC) 1 mg; zone of growth inhibition 7, 6.5 and 7 mm respectively). Aqueous extracts show activity against E. coli (MIC 5 mg) and P. aeruginosa (MIC 1 mg) while methanol extracts are active against P. aeruginosa and L. monocytogenes. G. lafifolium has potential food and antibacterial uses.展开更多
文摘Two new sterols, 3 beta, 7 alpha, 16 beta -trihydroxy-stigmast-5,22-diene (1), 3 beta, 7 alpha, 16 beta -trihydroxy-stigmast-5-ene (2), were isolated together with six known compounds, ergosta-5, 24(28)-dien-3 beta, 7 alpha -diol (3), ergosta-5,24(28)-dien-3 beta, 7 beta, 16 beta -triol (4), beta -amyrone (5), beta -amyrin (6), 11 alpha, 12 alpha -epoxy-14-taraxeren-3-one (7), and 6-guaiene-4 alpha, 10 alpha -diol (8) from the EtOH extract of the bark of Amoora yunnanensis (H. L. Li) C. Y. Wu. Their structures were deduced on the basis of spectral data.
文摘The chemical constituents, pharmacological activity and traditional uses of 20 species attributed to the genus Elsholtzia (Labiatae) used in China are reviewed and compared. A survey of the literature available shows that these species are used mostly for the treatment of respiratory and gastrointestinal disorders. Additionally, some of these Elsholtzia species show antibacterial, anti-inflammatory, relieving fever, analgesic activities and myocardial ischemia protection. Generally, the essential oils or flavonoids from these plant extracts are assumed to be the active principles.
文摘Aim To investigate novel bioactive and structural metabolites from marineorganisms. Methods Column chromatography in association with semi-preparative HPLC were used for theisolation of compounds. 1D and 2D NMR, IR, UV, and MS were employed for structure elucidation.Results From the butanol fraction of the 95% EtOH extract of the starfish Asterias rollestoni, a newcompound N^7 -2'-deoxypseudoxanthosine (1), along with sixteen known compounds, 2'-0-methyl-inosine(2), 2'-deoxyinosine (3), 2'-0-methylguanosine (4), inosine (5); thymine (6), uracil (7), thymidine(8), deoxyuridine (9), 2'-0-methyluridine (10), ( ― )-(1S, 3S)-1-methyl-1, 2, 3,4-terrahydro-β-carboline-3-carboxyl-ic acid (11), ( ― )-(1R, 3S)-1-methyl-1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (12) , ( ― )-(3S)- 1, 2, 3,4-tetrahydro-β-carboline-3-carboxylic acid (13), L-tryptophan (14), L-phenylalanine (15), 3-carboxyindole (16), and p-hydroxybenzoic acid (17) , have been isolated. Conclusion Compound 1 is a newnatural product, and compounds 8, 9 and 10 are isolated from natural sources for the first time, andthe known compounds except 14 and 15 are first reported from starfish Asterias rollestoni.
基金Supported by the Special Fund of Hongyun Honghe Tobacco(Group)Co.,Ltd~~
文摘[Objective] This study aimed to reduce the content of cell wall materials in tobacco stems and improve their internal quality. [Method] Pectinase was used to decompose cell wall materials in tobacco stems, followed by determination of the contents of four cell wall materials, six routine chemical components, as well as aroma constituents. [Result] Pectinase could effectively reduce the contents of cell wall materials in tobacco stems, with the largest decrease of 6.84%; after pectinase treatment,the content of reducing sugar in tobacco stems increased obviously, and the contents of total sugar, potassium ion, chloride ion and total nitrogen increased to varying degrees, of which the contents of potassium ion and reducing sugar displayed upward trends with the increase of pectinase concentration. Pectinase treatment significantly increased the contents of Maillard reaction products, with the most increase of 67.2%;the contents of carotenoid degradation products, phenylalanine degradation products and neophytadiene all increased to varying extents, and the contents of both Maillard reaction products and phenylalanine degradation products revealed ascending trends with the increase of pectinase concentration. [Conclusion] Pectinase treatment can effectively decompose cell wall materials in tobacco stems, improve routine chemical constituents, and increase the contents of aroma constituents.
基金The study was supported by Natural Science Foundation of Beijing to Wang Yuzhu (No. 6992013).
文摘In 2000 and 2001, 1-year-old seedlings of 7 economic tree species including chestnut, apricot, persimmon, peach, walnut, pear and apple were cultured in garden pots that had a diameter of 40 cm and were filled with clean sand. The major components of exudates released from their roots were isolated and analysed by GC-MS. Totally 200 kinds of organic chemicals were isolated, of which 3 kinds i.e. naphthalene, dimethylbenzene and dibutyl phthalate were principally controlled pollutants according to 'Blacklist of Principal Environment Pollutants in China' and the standard of U.S. Environmental Protection Agency (EPA). The research result provided theoretical evidence for selecting low-pollution economic forest crops in the water source protection area in Miyun Reservoir.
文摘Four diterpenoids, including a new ent-kaurane diterpene (1), were isolated from the rhizome of Aralia fargesii Franch. On the basis of chemical and spectral evidence (IR, EI-MS, HREI-MS, H-1-NMR, C-13-NMR and HMQC), the structure of compound 1 was established to be 17-acetoxy-16alpha-ent-kauran-19-oic acid The other three known compounds were identified as ent-pimera-8(14) 15-dien-19-oic acid (2), 16alpha-hydroxy-( -)-kauran-19-oic acid (3) and 16alpha-17-dihydroxy-ent-kauran-19-oic acid (4). The three known diterpenoids were obtained from this plant for the first time.
基金This project is supported by National Center of New Drug Research,Science and Technology Committee and Educational Committee of Shanghai.
文摘Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosin-7-0-(3-D-glucopyranoside) were isolated from the roots of Astragalus mem-branaceus (Fisch.) Bunge. Their structures were established by spectral analysis.
文摘Through field experiment,special biological fertilizer and cake fertilizer were applied collectively to tobacco,and chemical compositions of Wanxi flue-cured tobacco leaves were researched.The results showed that the increase of biological organic fertilizer would significantly improve soil nutrient supplying capacity.Compared with conventional fertilization,the contents of reducing sugar,total sugar and starch in different parts of tobaccos which were applied with biological organic fertilizer were closer to standards of excellent tobacco.In the treatment,the ratio of reducing sugar and nicotine in tobacco was more suitable in middle and lower parts of the plant and the contents of total N,nicotine and chlorine in tobacco were lowered,improving tobacco quality.
基金Supported by Science and Technology Development Project of Shangdong Province "Study on Standardized Planting of Chinese Herbal Medicines in Central China and Comprehensive Development and Utilization Technology of Bulk Chinese Herbs"(2011BAI06B00)Construction Project of Scientific and Technological Plat form for Quality Control of Genuine Medicinal Materials in Shangdong Province(2008GG-2NS02022)+1 种基金Agricultural Thoroughbred Breeding Project of Shangdong Province(2009LZ01-03)Independent Innovation Project of Universities and Institutes from Science and Technology Bureau of Ji'nan City(200906028)~~
文摘[Objective] This study aimed to investigate the differences in chemical composition of supercritical CO2 extraction products in peels of Trichosanthes kirilowii Maxim. from Changqing district. [Method] Supercritical fluidextraction (SFE) and GCMS method were applied to determine and analyze the chemical components of the extracts in peels of three strains of Trichosanthes kirilowii Maxim. [Result] The chemical components of supercritical CO2 extraction products in peels of three strains of Trichosanthes kirilowii Maxim. varied., and the number of chemical components with normalized percentage content higher than 1% was 5, 7 and 8, respectively. There are 14 kinds of common components, and the relative content of hexadecanoic acid was the highest. [Conclusion] Supercritical CO2 extracts in peels of different strains of Trichosanthes kirilowii Maxim. contain different chemical components, providing scientific basis for breeding excellent varieties and the development and utilization of Trichosanthes kirilowii Maxim.
基金Project(50731002) supported by the National Natural Science Foundation of ChinaProject(20082030) supported by the Natural Science Foundation of Liaoning Province,China
文摘The phase equilibria and compositions in Mg-rich side at 300 ℃ were investigated in Mg-Zn-Ca ternary system through the equilibrated alloy method by using scanning electron microscopy,electron probe microanalysis,X-ray diffraction and transmission electron microscopy.The results show that two ternary compounds T1 and T2 can be in equilibrium with the Mg-based solid solution in Mg-Zn-Ca system.T1 phase is a linear compound with the composition region(molar fraction) of 15% Ca,20.5%-48.9% Zn and balanced Mg at 300 ℃.Its hexagonal structure parameters decrease with increasing Zn content,i.e.a=0.992-0.945 nm,c=1.034-1.003 nm.T2 phase has hexagonal structure with the composition region of 26.4%-28.4% Mg,63.2%-65.5% Zn and 7.1%-8.4% Ca.At 300 ℃,the solubility of Zn in the Mg-based solid solution increases for the addition of Ca,the maximum solubility of Zn is 3.7%.Three-phase fields consisting of--Mg+Mg2Ca+T1,--Mg+T1+T2,--Mg+T2+MgZn and MgZn+T2+Mg2Zn3 exist in the Mg-Zn-Ca system at 300 ℃.
基金This project was sponsored by Shanghai Science Committee (97541900-7)
文摘Two novel compounds, clemaphenol A and dihydro-4-hydroxy-5-hyroxymethyl-2(3H)-fura-none were isolated together with eight known compounds, isoferulic acid, b-sitosterol, daucosterol, 5-hy-droxymethyl-2-furancarboxaldehyde, 5-hydroxy-4-oxo-pentanoic acid, palmitic acid, linoleic acid and anemonin from the root of Clematis chinensis Osbeck.
基金The present work was supported by Foundation of State Key Basic Research and Development Project (G1998051100)
文摘Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergosta-7,22-diene-3,6-dione (2) respectively on the basis of spectral analyses and physical and chemical identifications. Compound 1 was a new natural product. Compound 2 was firstly isolated from its genus. Spectral data of 1 and complete 1H NMR data of 2 were reported for the first time.
文摘Aim Isolation and structural elucidation of the constituents from the aerialpart of Hypericum perforatum L. Methods Column chromatography and TLC were used to isolate chemicalconstituents. Physico-chemical characterization and spectroscopic analysis were employed forstructural identification. Results Three flavonols were isolated and identified. Conclusion Compound1 is a novel natural product and its structure has been characterized to be 3, 5, 7-trihydroxy-3',4'-isopropyldioxy-flavone.
文摘The forms of phosphorus and silicon in the natural grain sizes surface sediments of the southern Bohai Sea were studied. In sediments, the organic matter bound form of phosphorus was the main form of transferable phosphorus and ranged from 0.37 μmol/g to 1.57 μmol/g, accounting for 10.7% of the total phosphorus, others were the carbonate bound form, iron manganese oxide bound form and ion exchange able form; the transferable form of phosphorus accounted for 19.2% of the total phosphorus. Silicon’s carbonate bound form was predominant over others among its transferable forms, and content ranged from 1.55 μmol/g to 8.94 μmol/g, accounting for 0.05% of the total silicon; the total amount of transferable silicon forms accounted for only 0.12% of the total silicon. Therefore, 19.2% of the total phosphorus and 0.12% of the total silicon contained in the surface sediments of the southern Bohai Sea could participate in the biogeochemical cycling.
基金Project supported by the Outstanding Youth Fund of National Natural Science Foundation of China, the National Key Basic Research Support Foundation (NKBRSF) of China (No. 2002CB410805) and the Federal Ministry of Education and Research, Germany.
文摘Two procedures were compared for extraction and clean-up of 20organophosphorus and 19 pyrethroid pesticides in sediment to identify the more effective procedurefor groups of pesticides or individual compounds. In Procedure I, methanol/water and n-hexane wereused for extraction, and 1:10 (v/v) dichloromethane in n-hexane and acetone were used as eluents foreluting the analyte through the cartridge, with one evaporating steps on a rotary evaporator andtwo eluting steps on the cartridge. n-hexane/acetone (2:1, v/v) was used for extraction and elutionin Procedure II with one evaporating step on a rotary evaporator and one eluting step on thecartridge. All extractions were performed under an ultrasonic bath and gas chromatography and massspectrometry were utilized for measurements. Procedure II was developed as a rapid, timesaving, lesscostly and safer substitute for Procedure I which was an old method. Procedure II was moreeffective for almost all the organophosphorus pesticides tested and 11of the 19 pyrethroidpesticides, while Procedure I was more appropriate for analysis of 5 pyrethroid pesticides. However,recoveries of most pyrethroid pesticides were fairly low. Thus, further studies should focus onadjustment and formulation of solvents for more efficient extraction and clean-up of pyrethroidpesticides from sediment samples.
文摘Chemical composition of Gongronema latifolium leaves was determined using standard methods. Aqueous and methanol G. latifolium extracts were tested against thirteen pathogenic bacterial isolates. Crude protein, lipid extract, ash, crude fibre and nitrogen flee extractives obtained are: 27.2%, 6.07%, 11.6%, 10.8% and 44.3% dry matter respectively. Potassium, sodium, calcium, phosphorus and cobalt contents are 332, 110, 115, 125 and 116 mg/kg respectively. Dominant essential amino acids are leucine, valine and phenylalanine. Aspartic acid, glutamic acid and glycine are 13.8%, 11,9% and 10.3% respectively of total amino acid. Saturated and unsaturated fatty acids are 50.2% and 39.4% of the oil respectively. Palmitic acid makes up 36% of the total fatty acid. Extracts show no activity against E. faecalis, Y. enterolytica, E. aerogenes, B. cereus and E. agglomerans. Methanol extracts were active against S, enteritidis, S. cholerasius ser typhimurium and P. aeruginosa (minimum inhibitory concentration (MIC) 1 mg; zone of growth inhibition 7, 6.5 and 7 mm respectively). Aqueous extracts show activity against E. coli (MIC 5 mg) and P. aeruginosa (MIC 1 mg) while methanol extracts are active against P. aeruginosa and L. monocytogenes. G. lafifolium has potential food and antibacterial uses.