A fossil with Gnetum affinity was found in the Jianshangou Member （Barremian Age） of the Yixian Formation （Lower Cretaceous Epoch） of the Jehol Group in western Liaoning, northeastern China. The single fossil spec...A fossil with Gnetum affinity was found in the Jianshangou Member （Barremian Age） of the Yixian Formation （Lower Cretaceous Epoch） of the Jehol Group in western Liaoning, northeastern China. The single fossil specimen is represented by both elongate-cylindrical male spike strobiles which borne within a nodal bract of cauliflorous branch. The spike strobiles have apparent nodes, invisible internodes, and numerous verticillate involucral collars. The microsporangiate units within involucral collars are not seen. The male spike strobiles with verticillate involucral collars occur exclusively in Gnetum; hence, the fossil strobiles are attributed to a new taxon, Khitania columnispicata gen. ＆ sp. nov., being closely related to Gnetum. The general isotopic dating suggests an age of Barremian, ca. 125-122 million years （Myr） ago for the Jianshangou Member. The palaeoecological and palaeoclimatic inference based on the compositions of flora and fauna, and lithological characters of the fossil locality suggests that the fossil plants grew in a subtropical mesophytic forest and under a warmer climate. The remains of male spike strobiles are the first record of gnetalean macrofossil. It documents the evolution of the distinct gnetoid morphology and indicates a wider range of distribution of Gnetaceae in the Early Cretaceous than present day.展开更多
Research for bioactive molecules and not resistant to infectious agents remains topical for science. The total polyphenols (TPP) and total flavonoids (TFv) of the hydroethanolic extracts and fractions obtained were qu...Research for bioactive molecules and not resistant to infectious agents remains topical for science. The total polyphenols (TPP) and total flavonoids (TFv) of the hydroethanolic extracts and fractions obtained were quantified according to the spectrophotometric method described in the literature using the Folin-Ciocalteu reagent and the colorless solutions of sodium nitrite 2.5% and aluminum chloride 10% respectively. The characterization of chemical compounds was made by coupling liquid chromatography (LC) and mass spectroscopy (MS). Thus, 15 chemical compounds were characterized, seven from Gnetum africanum (EBa) and eight from Gnetum buchholzianum (EBb). The majority of which were stilbens, such as Gnetupendin D, Dimethoxygnetulin, Methoxyparvifolol D, Isorhaponcitin from Eba and Gnetuhaidin P, Gnetupendin D, Gnetuhainin C, phenols (Alcohol Homovanillyl, Alcohol Erythro guaiacylglycerol-β-O-4'-coniferyl, and Alcohol Homovanillyl from EBb. The minority were flavonoids such as Dimethoxydihydropyraneriodictyol, Dimethoxyeriodictyol (EBa) and Dimethoxydihydropyraneriodictyol, Trimethoxyluteolin (EBb). The levels of total polyphenolics and total flavonoids content were respectively 14.520 ± 0.557 mg EAA/g Extract and 29.870 ± 2.485 mg EQ/g Extract for EBa. The levels of total polyphenolics and total flavonoids content for EBb were respectively 4.560 ± 0.010 mg EAA/g Extract and 2.233 ± 0.251 mg EQ/g Extract. The high levels of flavonoids content respectively 220.200 ± 35.500 and 335.300 ± 57.810 mg EQ/g Extract were shown in Dichlorometan fraction from EBa and EBb. These bioactive compounds identified and total phenolics compounds quantified can be exploited in pharmacological and pharmacokinetical activities to fight against multi-resistant infectious agents and as well as oxidative stress and antiinflammatory diseases.展开更多
Gnetuhainin S, a new resveratrol dimer, was isolated from the lianas of Gnetum hainanense C. Y. Cheng. Its structure and relative configuration were established on the basis of spectroscopic evidence.
Gnetuhainin P, a new isorhapontigenin dimer, was isolated from the Lianas of Gnetum hainanense C. Y. Cheng. Its structure was established on the basis of spectroscopic evidence, especially 2D NMR techniques.
A pair of dimeric stilbenes, gnetifolin M and gnetifolin N were isolated from the lianas of Gnetum montanum. All attempts to separate them by HPLC were unsuccessful. Their str-uctures were elucidated by the spectrosco...A pair of dimeric stilbenes, gnetifolin M and gnetifolin N were isolated from the lianas of Gnetum montanum. All attempts to separate them by HPLC were unsuccessful. Their str-uctures were elucidated by the spectroscopic analysis including 2D-NMR studies on the peracetate.展开更多
This study was conducted to assess the toxic effect of hydroethanolic extract combinations of Gnetum africanum Welv. leaves and Gnetum buchholzianum Engl. (Gnetaceae) in experimental rats to test the validity of the t...This study was conducted to assess the toxic effect of hydroethanolic extract combinations of Gnetum africanum Welv. leaves and Gnetum buchholzianum Engl. (Gnetaceae) in experimental rats to test the validity of the treatment of liver disorders related to oxidative stress. The Combinations (m/m) 50-50 for E2 and 75-25 for E3 of ethanol-water extracts from plant leaves at the respective doses of 100, 200, and 400 mg/kg of body weight were used for 32-day toxicity. They were obtained after harvesting leaves, sorting, drying in the air cover for three weeks, and grinding. The resulting powder was doubly macerated with 70% ethanol for 48 hours and filtered. The filtrate was concentrated with the Heidolph-brand rotary rotavapor and each extract obtained was preserved. The administrations were carried out by gavage to wistar, male and non-pregnant female albino rats. In the end, the animals were sacrificed. The serum and organ homogenates were obtained for biochemical, tissue, and histopathological analyses respectively. The analyses revealed insignificant variations at the 5% probability threshold of the weight growth of experimental animals. These variations were found to be statistically significant at the same probability for biochemical and tissue parameters based on the dose of plant extracts and compared to control animals. Histopathological analysis of liver tissue showed leukodate infiltration that indicates extract-induced inflammation of the hepatocytes at the 400 mg/kg dose of body weight in females. However, this infiltration of the cells would have improved the regeneration of hepatocytes justified by the normal rate of transaminases. These results showed that combinations of hydroethanolic extracts of G. africanum and G. buchholzianumare non-toxicand may be potential candidates in the Cameroonian flora medicinal plant database shown in the monitoring of oxidative stress-related diseases.展开更多
The inhibition of copper corrosion by acid extract of Gnetum africana was studied using weight loss method of monitoring corrosion rate. The inhibition of Gnetum africana on copper corrosion was optimized by applicati...The inhibition of copper corrosion by acid extract of Gnetum africana was studied using weight loss method of monitoring corrosion rate. The inhibition of Gnetum africana on copper corrosion was optimized by application of 23 factorial design. While the interactive effects of temperature, inhibition concentration and reaction time were investigated, the input factors and output response were also optimized. Optimum conditions for inhibition of Gnetum africana on copper corrosion were recorded at temperature of 303 K, reaction time of 24 h and inhibition concentration of 0.003 g/L. It could be concluded that factorial design was adequately applicable in the optimization of process variables and that Gnetuma africana sufficiently inhibited the corrosion of copper at the conditions of the experiment.展开更多
Two new dimeric stilbenes, named gnetifolin L and gnetifolin O, were isolated from the alcoholic extract of lianas of Gnetum montanum. Their structures were elucidated mainly on the basis of spectroscopic data includi...Two new dimeric stilbenes, named gnetifolin L and gnetifolin O, were isolated from the alcoholic extract of lianas of Gnetum montanum. Their structures were elucidated mainly on the basis of spectroscopic data including 2D-NMR studies on peracetate derivatives.展开更多
Gnetupendin C, a new dimer coupled by a resveratrol and an oxyresveratrol unit, was isolated from the lianas of Gnetum pendulum C.Y. Cheng (Gnetaceae). Its structure was established on the basis of spectroscopic evide...Gnetupendin C, a new dimer coupled by a resveratrol and an oxyresveratrol unit, was isolated from the lianas of Gnetum pendulum C.Y. Cheng (Gnetaceae). Its structure was established on the basis of spectroscopic evidence, especially 2D techniques.展开更多
Root failure is a key limiting factor in Gnetum spp. domestication and production of plants materials for farming. To overcome, root failure in Gnetum spp. may depend on adequate strategies set up and understanding of...Root failure is a key limiting factor in Gnetum spp. domestication and production of plants materials for farming. To overcome, root failure in Gnetum spp. may depend on adequate strategies set up and understanding of biochemical markers controlling the rooting process. The present work is principally based on phenolic compounds contents, peroxidasic and polyphenol oxidasic activities during rooting of cuttings (pretreated with IBA, ANA and IAA) at induction, initiation and expression phases of roots formation in Gnetum africanum Welw. and G. buchholzianum Engl. The study revealed that cuttings pretreated with IBA (150 mg/l) were more effective than IAA and NAA. Phenolic compounds analysis revealed that cuttings pretreated with IBA exhibited high phenolic compound contents at initiation and expression phases for both Gnetum species. Indicating that IBA pretreatment promotes phenolic compounds synthesis and accumulation necessary for roots differentiation. Enzyme contents appear to be high during the initiation stage for both species when they are pretreated with IBA (150 mg/l). Peroxidasic and Polyphenol oxidasic activities evolved on the synchroneous maner. This allows us to know that the implication of these enzymes in the rooting process is fundamental makers.展开更多
The leaves of Gnetum africanum were studied for their proximate (nutrient), mineral (elemental) and phytochemical constituents. All analyses were done using standard analytical procedures and the results obtained show...The leaves of Gnetum africanum were studied for their proximate (nutrient), mineral (elemental) and phytochemical constituents. All analyses were done using standard analytical procedures and the results obtained showed a moisture content, crude protein, ash content, crude fibre, crude lipids and carbohydrates of 10.9%, 20.12%, 6.70%, 7.10%, 2.79% and 52.39% respectively. The mineral (elemental) analysis showed the presence of sodium, magnessium, calcium, iron, zinc, manganesse, potassium and copper in that order of decreasing concentration while notably absent was chromium and lead in the examined leaves. The phytochemicals detected in the leaves using various selected solvents were alkaloids, saponins, glycosides and tannins with various concentrations while flavonoids, phenols and steroids were totally absent. From the results of the aforementioned analyses, it could be concluded that the leaves of Gnetum africanum contain some beneficial nutrients, mineral elements and secondary metabolites justifying the medicinal status and possible potency of the plant part.展开更多
Objective To investigate the effect of ethanolic and water extracts of the leaves of Gnetum africanum on the morphology of uterine smooth muscles of rats. Methods Three tolerated doses of the extracts, 10 mg/kg, 200 m...Objective To investigate the effect of ethanolic and water extracts of the leaves of Gnetum africanum on the morphology of uterine smooth muscles of rats. Methods Three tolerated doses of the extracts, 10 mg/kg, 200 mg/kg and 700 mg/kg per day, were obtained from the results of acute toxicity test and administered orally to three respective groups of female rats for 3 d and saline group of rats served as the negative control （0 mg/ml）, 17β-estradiol group of rats served as the positive group, 5 rats per group. Rats from each of the groups were sacrificed on the 4th day and their uteri were carefully isolated and examined. Results The study revealed that both extracts of the leaves of Gnetum africanum influenced the uterine muscle weight and growth of both adult and immature female rats in a similar manner as 17β-estradiol. Conclusion The leaves of Gnetum africanum may be phytoestrogenic and could influence fetal implantation or ova fertilization, therefore, abuse in the use of the leaves of Gnetum africanum as vegetable in some Nigerian meal. Meanwhile this effect is reversible, the plant-extracts could be possibly developed as a female contraceptive to control birth rate.展开更多
基金supported by the pilot project of Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-114)National Natural Science Foundation of China (40632010)
文摘A fossil with Gnetum affinity was found in the Jianshangou Member （Barremian Age） of the Yixian Formation （Lower Cretaceous Epoch） of the Jehol Group in western Liaoning, northeastern China. The single fossil specimen is represented by both elongate-cylindrical male spike strobiles which borne within a nodal bract of cauliflorous branch. The spike strobiles have apparent nodes, invisible internodes, and numerous verticillate involucral collars. The microsporangiate units within involucral collars are not seen. The male spike strobiles with verticillate involucral collars occur exclusively in Gnetum; hence, the fossil strobiles are attributed to a new taxon, Khitania columnispicata gen. ＆ sp. nov., being closely related to Gnetum. The general isotopic dating suggests an age of Barremian, ca. 125-122 million years （Myr） ago for the Jianshangou Member. The palaeoecological and palaeoclimatic inference based on the compositions of flora and fauna, and lithological characters of the fossil locality suggests that the fossil plants grew in a subtropical mesophytic forest and under a warmer climate. The remains of male spike strobiles are the first record of gnetalean macrofossil. It documents the evolution of the distinct gnetoid morphology and indicates a wider range of distribution of Gnetaceae in the Early Cretaceous than present day.
文摘Research for bioactive molecules and not resistant to infectious agents remains topical for science. The total polyphenols (TPP) and total flavonoids (TFv) of the hydroethanolic extracts and fractions obtained were quantified according to the spectrophotometric method described in the literature using the Folin-Ciocalteu reagent and the colorless solutions of sodium nitrite 2.5% and aluminum chloride 10% respectively. The characterization of chemical compounds was made by coupling liquid chromatography (LC) and mass spectroscopy (MS). Thus, 15 chemical compounds were characterized, seven from Gnetum africanum (EBa) and eight from Gnetum buchholzianum (EBb). The majority of which were stilbens, such as Gnetupendin D, Dimethoxygnetulin, Methoxyparvifolol D, Isorhaponcitin from Eba and Gnetuhaidin P, Gnetupendin D, Gnetuhainin C, phenols (Alcohol Homovanillyl, Alcohol Erythro guaiacylglycerol-β-O-4'-coniferyl, and Alcohol Homovanillyl from EBb. The minority were flavonoids such as Dimethoxydihydropyraneriodictyol, Dimethoxyeriodictyol (EBa) and Dimethoxydihydropyraneriodictyol, Trimethoxyluteolin (EBb). The levels of total polyphenolics and total flavonoids content were respectively 14.520 ± 0.557 mg EAA/g Extract and 29.870 ± 2.485 mg EQ/g Extract for EBa. The levels of total polyphenolics and total flavonoids content for EBb were respectively 4.560 ± 0.010 mg EAA/g Extract and 2.233 ± 0.251 mg EQ/g Extract. The high levels of flavonoids content respectively 220.200 ± 35.500 and 335.300 ± 57.810 mg EQ/g Extract were shown in Dichlorometan fraction from EBa and EBb. These bioactive compounds identified and total phenolics compounds quantified can be exploited in pharmacological and pharmacokinetical activities to fight against multi-resistant infectious agents and as well as oxidative stress and antiinflammatory diseases.
文摘Gnetuhainin S, a new resveratrol dimer, was isolated from the lianas of Gnetum hainanense C. Y. Cheng. Its structure and relative configuration were established on the basis of spectroscopic evidence.
文摘Gnetuhainin P, a new isorhapontigenin dimer, was isolated from the Lianas of Gnetum hainanense C. Y. Cheng. Its structure was established on the basis of spectroscopic evidence, especially 2D NMR techniques.
文摘A pair of dimeric stilbenes, gnetifolin M and gnetifolin N were isolated from the lianas of Gnetum montanum. All attempts to separate them by HPLC were unsuccessful. Their str-uctures were elucidated by the spectroscopic analysis including 2D-NMR studies on the peracetate.
文摘This study was conducted to assess the toxic effect of hydroethanolic extract combinations of Gnetum africanum Welv. leaves and Gnetum buchholzianum Engl. (Gnetaceae) in experimental rats to test the validity of the treatment of liver disorders related to oxidative stress. The Combinations (m/m) 50-50 for E2 and 75-25 for E3 of ethanol-water extracts from plant leaves at the respective doses of 100, 200, and 400 mg/kg of body weight were used for 32-day toxicity. They were obtained after harvesting leaves, sorting, drying in the air cover for three weeks, and grinding. The resulting powder was doubly macerated with 70% ethanol for 48 hours and filtered. The filtrate was concentrated with the Heidolph-brand rotary rotavapor and each extract obtained was preserved. The administrations were carried out by gavage to wistar, male and non-pregnant female albino rats. In the end, the animals were sacrificed. The serum and organ homogenates were obtained for biochemical, tissue, and histopathological analyses respectively. The analyses revealed insignificant variations at the 5% probability threshold of the weight growth of experimental animals. These variations were found to be statistically significant at the same probability for biochemical and tissue parameters based on the dose of plant extracts and compared to control animals. Histopathological analysis of liver tissue showed leukodate infiltration that indicates extract-induced inflammation of the hepatocytes at the 400 mg/kg dose of body weight in females. However, this infiltration of the cells would have improved the regeneration of hepatocytes justified by the normal rate of transaminases. These results showed that combinations of hydroethanolic extracts of G. africanum and G. buchholzianumare non-toxicand may be potential candidates in the Cameroonian flora medicinal plant database shown in the monitoring of oxidative stress-related diseases.
文摘The inhibition of copper corrosion by acid extract of Gnetum africana was studied using weight loss method of monitoring corrosion rate. The inhibition of Gnetum africana on copper corrosion was optimized by application of 23 factorial design. While the interactive effects of temperature, inhibition concentration and reaction time were investigated, the input factors and output response were also optimized. Optimum conditions for inhibition of Gnetum africana on copper corrosion were recorded at temperature of 303 K, reaction time of 24 h and inhibition concentration of 0.003 g/L. It could be concluded that factorial design was adequately applicable in the optimization of process variables and that Gnetuma africana sufficiently inhibited the corrosion of copper at the conditions of the experiment.
文摘Two new dimeric stilbenes, named gnetifolin L and gnetifolin O, were isolated from the alcoholic extract of lianas of Gnetum montanum. Their structures were elucidated mainly on the basis of spectroscopic data including 2D-NMR studies on peracetate derivatives.
文摘Gnetupendin C, a new dimer coupled by a resveratrol and an oxyresveratrol unit, was isolated from the lianas of Gnetum pendulum C.Y. Cheng (Gnetaceae). Its structure was established on the basis of spectroscopic evidence, especially 2D techniques.
文摘Root failure is a key limiting factor in Gnetum spp. domestication and production of plants materials for farming. To overcome, root failure in Gnetum spp. may depend on adequate strategies set up and understanding of biochemical markers controlling the rooting process. The present work is principally based on phenolic compounds contents, peroxidasic and polyphenol oxidasic activities during rooting of cuttings (pretreated with IBA, ANA and IAA) at induction, initiation and expression phases of roots formation in Gnetum africanum Welw. and G. buchholzianum Engl. The study revealed that cuttings pretreated with IBA (150 mg/l) were more effective than IAA and NAA. Phenolic compounds analysis revealed that cuttings pretreated with IBA exhibited high phenolic compound contents at initiation and expression phases for both Gnetum species. Indicating that IBA pretreatment promotes phenolic compounds synthesis and accumulation necessary for roots differentiation. Enzyme contents appear to be high during the initiation stage for both species when they are pretreated with IBA (150 mg/l). Peroxidasic and Polyphenol oxidasic activities evolved on the synchroneous maner. This allows us to know that the implication of these enzymes in the rooting process is fundamental makers.
文摘The leaves of Gnetum africanum were studied for their proximate (nutrient), mineral (elemental) and phytochemical constituents. All analyses were done using standard analytical procedures and the results obtained showed a moisture content, crude protein, ash content, crude fibre, crude lipids and carbohydrates of 10.9%, 20.12%, 6.70%, 7.10%, 2.79% and 52.39% respectively. The mineral (elemental) analysis showed the presence of sodium, magnessium, calcium, iron, zinc, manganesse, potassium and copper in that order of decreasing concentration while notably absent was chromium and lead in the examined leaves. The phytochemicals detected in the leaves using various selected solvents were alkaloids, saponins, glycosides and tannins with various concentrations while flavonoids, phenols and steroids were totally absent. From the results of the aforementioned analyses, it could be concluded that the leaves of Gnetum africanum contain some beneficial nutrients, mineral elements and secondary metabolites justifying the medicinal status and possible potency of the plant part.
文摘Objective To investigate the effect of ethanolic and water extracts of the leaves of Gnetum africanum on the morphology of uterine smooth muscles of rats. Methods Three tolerated doses of the extracts, 10 mg/kg, 200 mg/kg and 700 mg/kg per day, were obtained from the results of acute toxicity test and administered orally to three respective groups of female rats for 3 d and saline group of rats served as the negative control （0 mg/ml）, 17β-estradiol group of rats served as the positive group, 5 rats per group. Rats from each of the groups were sacrificed on the 4th day and their uteri were carefully isolated and examined. Results The study revealed that both extracts of the leaves of Gnetum africanum influenced the uterine muscle weight and growth of both adult and immature female rats in a similar manner as 17β-estradiol. Conclusion The leaves of Gnetum africanum may be phytoestrogenic and could influence fetal implantation or ova fertilization, therefore, abuse in the use of the leaves of Gnetum africanum as vegetable in some Nigerian meal. Meanwhile this effect is reversible, the plant-extracts could be possibly developed as a female contraceptive to control birth rate.
