Alleviation of carbon tetrachloride-induced hepatocellular damage and oxidative stress with a leaf extract of Glyphae brevis (Tiliaceae).

Background Glyphae brevis leaf is reported in ethnomedicine as a treatment for hepatitis and jaundice; however, no studies have hitherto investigated the mechanistic basis of these claims. Methods A hepato-protective role of G. brevis hydromethanolic (GBH) leaf extract was established against carbon tetrachloride (CCl4)-induced hepatotoxicity. Twenty-four hours after a CCl4 challenge, rats were sacrificed and serum hematological indices, lipid profile, and biochemical parameters were determined. The antioxidant enzymes parameters (glutathione, catalase, and superoxide dismutase) and lipid peroxidation product (thiobarbituric reactive substances) levels in liver homogenates were evaluated. Changes in the liver cyto-architecture of different treatment groups were also investigated. Results The GBH extract produced no significant impact on weight and hematological indices. Intoxication with CCl4 significantly (p<0.001-0.05) increased total cholesterol (TC) and low-density lipoproteins (LDL) compared with control rats. Pretreatment with GBH leaf extract significantly reduced triglycerides, TC, and LDL to approaching control levels (p<0.001-0.05). The GBH leaf extract significantly alleviated CCl4-induced elevation of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and the CCl4-induced depression of total protein, and albumin. Liver antioxidant parameters were significantly increased in plant extract-treated rats, and this antagonized the pro-oxidant effect of CCl4. Histopathological studies also supported a hepato-protective effect of GBH. Collectively, the GBH leaf extract alleviated the CCl4-induced hepatotoxicity through improvement of innate antioxidant enzyme levels and lipid metabolism and stabilized the hepatocyte cyto-architecture of intoxicated rats. Conclusions This study establishes the ethnomedicinal role of G. brevis leaf in hepatitis and the mechanistic basis of hepato-protection against CCl4-induced hepatotoxicity.

Development and characterization of microsatellite loci in Excentrodendron hsienmu (Chun & How) H.T. Chang& R.H. Miau.

Microsatellite markers were isolated using dual-suppression-PCR for the endangered species Excentrodendron hsienmu (Tiliaceae) to evaluate the genetic diversity and population structure of this species. A total of 11 polymorphic microsatellite loci were characterized in E. hsienmu. The number of alleles per locus ranged from 2 to 9, with an average of 5.27. The expected heterozygosity value ranged from 0.053 to 0.780, with an average of 0.568 and the observed heterozygosity value ranged from 0 to 0.595, with an average of 0.268. The polymorphic information content value ranged from 0.051 to 0.740, with an average of 0.521. These newly designed markers will be of great potential significance and profound influence in future research related to the genetic diversity, population structure, and patterns of gene flow of this species, which will contribute to the implementation of conservation and management strategies for this species.

Qualitative phytochemical screening and evaluation of anti-inflammatory, analgesic and antipyretic activities of Microcos paniculata barks and fruits.

OBJECTIVE: The main objectives of this study were to qualitatively evaluate the profile of phytochemical constituents present in methanolic extract of Microcos paniculata bark (BME) and fruit (FME), as well as to evaluate their anti-inflammatory, analgesic and antipyretic activities. METHODS: Phytochemical constituents of BME and FME were determined by different qualitative tests such as Molisch's test, Fehling's test, alkaloid test, frothing test, FeCl3 test, alkali test, Salkowski's test and Baljet test. The anti-inflammatory, analgesic and antipyretic activities of the extracts were evaluated through proteinase-inhibitory assay, xylene-induced ear edema test, cotton pellet-induced granuloma formation in mice, formalin test, acetic acid-induced writhing test, tail immersion test and Brewer's yeast-induced pyrexia in mice. RESULTS: M. paniculata extracts revealed the presence of carbohydrates, alkaloids, saponins, tannins, flavonoids and triterpenoids. All of the extracts showed significant (P<0.05, vs aspirin group) proteinase-inhibitory activity, whereas the highest effect elicited by plant extracts was exhibited by the BME (75.94% proteinase inhibition activity) with a half-maximal inhibitory concentration (IC50) of 61.31 µg/mL. Each extract at the doses of 200 and 400 mg/kg body weight showed significant (P<0.05, vs control) percentage inhibition of ear edema and granuloma formation. These extracts significantly (P<0.05, vs control) reduced the paw licking and abdominal writhing of mice. In addition, BME 400 mg/kg, and FME at 200 and 400 mg/kg showed significant (P<0.05, vs control) analgesic activities at 60 min in the tail immersion test. Again, the significant (P<0.05, vs control) post-treatment antipyretic activities were found by BME 200 and 400 mg/kg and FME 400 mg/kg respectively. CONCLUSION: Study results indicate that M. paniculata may provide a source of plant compounds with anti-inflammatory, analgesic and antipyretic activities.

Isolating the metabolic pathways involved in the hepatoprotective effect of Muntingia calabura against CCl4-induced liver injury using LC/MS Q-TOF.

ETHNOPHARMACOLOGICAL RELEVANCE: Muntingia calabura L. has been used in Southeast Asia and tropical America as antipyretic, antiseptic, analgesic, antispasmodic and liver tonic. This study aims to determine the acute toxicity and the metabolic pathways involved in the hepatoprotective mechanism of M. calabura. MATERIALS AND METHODS: CCl4-induced hepatotoxic rat model was developed and a dose dependent effect of M. calabura was conducted. Body weight, food and water consumption were measured every day and rats were sacrificed to collect the serum samples at the end of the 10-days treatment. Liquid chromatography-mass spectrometry quadrapole time of flight (LC/MS-QTOF) combined with principal component analysis (PCA) were used to determine differentially expressed metabolites due to treatment with CCl4 and M. calabura extracts. Metabolomics Pathway Analysis (MetPA) was used for analysis and visualization of pathways involved. RESULTS: Body weight, food and water consumption were significantly decreased and histopathological study revealed steatosis in CCl4-induced rats. PCA score plots show distinct separation in the metabolite profiles of the normal group, CCl4-treated group and extract of M. calabura (MCME) pre-treated groups. Biomarkers network reconstruction using MetPA had identified 2 major pathways which were involved in the protective mechanism of MCME. These include the (i) biosynthesis of the primary bile acid, (ii) metabolism of arachidonic acid. CONCLUSION: This study has successfully isolated 2 major pathways involved in the hepatoprotecive effect of MCME against CCl4-induced liver injury using the LC/MS Q-TOF metabolomics approach. The involvement of archidonic acid and purine metabolism in hepatoprotection has not been reported previously and may provide new therapeutic targets and/or options for the treatment of liver injury.

Qualitative phytochemical screening and evaluation of anti-inflammatory, analgesic and antipyretic activities of Microcos paniculata barks and fruits / 中西医结合学报

<p><b>OBJECTIVE</b>The main objectives of this study were to qualitatively evaluate the profile of phytochemical constituents present in methanolic extract of Microcos paniculata bark (BME) and fruit (FME), as well as to evaluate their anti-inflammatory, analgesic and antipyretic activities.</p><p><b>METHODS</b>Phytochemical constituents of BME and FME were determined by different qualitative tests such as Molisch's test, Fehling's test, alkaloid test, frothing test, FeCl3 test, alkali test, Salkowski's test and Baljet test. The anti-inflammatory, analgesic and antipyretic activities of the extracts were evaluated through proteinase-inhibitory assay, xylene-induced ear edema test, cotton pellet-induced granuloma formation in mice, formalin test, acetic acid-induced writhing test, tail immersion test and Brewer's yeast-induced pyrexia in mice.</p><p><b>RESULTS</b>M. paniculata extracts revealed the presence of carbohydrates, alkaloids, saponins, tannins, flavonoids and triterpenoids. All of the extracts showed significant (P<0.05, vs aspirin group) proteinase-inhibitory activity, whereas the highest effect elicited by plant extracts was exhibited by the BME (75.94% proteinase inhibition activity) with a half-maximal inhibitory concentration (IC50) of 61.31 μg/mL. Each extract at the doses of 200 and 400 mg/kg body weight showed significant (P<0.05, vs control) percentage inhibition of ear edema and granuloma formation. These extracts significantly (P<0.05, vs control) reduced the paw licking and abdominal writhing of mice. In addition, BME 400 mg/kg, and FME at 200 and 400 mg/kg showed significant (P<0.05, vs control) analgesic activities at 60 min in the tail immersion test. Again, the significant (P<0.05, vs control) post-treatment antipyretic activities were found by BME 200 and 400 mg/kg and FME 400 mg/kg respectively.</p><p><b>CONCLUSION</b>Study results indicate that M. paniculata may provide a source of plant compounds with anti-inflammatory, analgesic and antipyretic activities.</p>

Chemical constituents from Gouania longipetala and Glyphaea brevis.

Five compounds were isolated altogether from the two medicinal plants. Glycerol monotricosanoate (1), palmarumycin BG1 (2) and de-O-methyllasiodiplodin (3) were isolated from Gouania longipetala. In addition, epicatechin (4) and its dimer procyanidin B2 (5) were isolated from the stem bark of Glyphaea brevis. Their structures were elucidated by using spectroscopic experiments. They exhibited radical scavenging and moderate antibacterial effects.

A new taraxerol derivative from the roots of Microcos tomentosa.

A new 3beta-O-vanilloyl-taraxerol, microcisin (1) and eight known compounds, 3beta-taraxerol acetate (2), 3beta-taraxerol (3), cholest-4-en-3-one (4), cholest-4-en-6beta-ol-3-one (5), beta-sitosterol (6), 7-hydroxycadalene (7), mellein (8) and vanillin (9), were isolated from the roots of Microcos tomentosa. The structures were determined by extensive analysis of their spectroscopic data. All isolated compounds were evaluated for their cytotoxicity against KB and HeLa cells.

Avaliação da toxicidade aguda do extrato aquoso de Apeiba tibourbou Aubl (Tiliaceae), em camundongos e ratos / Assessment of acute toxicity of water extract from Apeiba tibourbou Aubl (Tiliaceae) in mice and rats

O teste de toxicidade aguda estima a dose letal mediana (DL50 ) e classifica os toxicantes quanto à periculosidade, inclusive para extratos de plantas. A espécie Apeiba tibourbou Aubl (Tiliaceae), conhecida como pau-de-jangada ou pente-de-macaco, é empregada popularmente como antirreumática, antiespasmódica e expectorante, embora seja desconhecida quanto aos seus efeitos tóxicos. Assim, o objetivo desta pesquisa foi investigar o potencial de toxicidade aguda do extrato aquoso de A. tibourbou (EAT), administrado por gavagem, em camundongos fêmeas e ratos fêmeas, seguindo as diretrizes OECD Guideline 423/2001 e o screening hipocrático. Os camundongos fêmeas foram divididos em três grupos de três animais cada (C1 – controle, água filtrada, 0,25 mL; C2 –300 mg/kg de EAT; e C3 – 2000 mg/kg de EAT). Os ratos fêmeas foram divididos em dois grupos de três animais cada (R1 – controle, água filtrada, 0,5 mL; e R2 – 2000 mg/kg de EAT). O grupo C2 consumiu 28% de água a mais que o grupo C1 (p < 0,05); o grupo C3 produziu 31% de excretas a mais que o grupo C1 (p < 0,0001); o grupo R2 reduziu o consumo de ração e a produção de excretas em 20% e 28% em relação ao grupo R1 (p < 0,05), respectivamente. No screening hipocrático, nenhuma alteração motora e/ou sensorial foi observada. Não houve morte nem estado moribundo de nenhum animal. Conclui-se que o EAT possui DL50 estimada maior que 2000 mg/kg (Classe 5 de toxicidade, segundo o Globally Harmonized System – GHS, ONU), demonstrando reduzido potencial de toxicidade aguda.

The acute toxicity test estimates the median lethal dose (LD50) against a given test organism and classifies toxic substances, including plant extracts, according to their intrinsic toxicity. Apeiba tibourbou Aubl (Tiliaceae), a tree known in Brazil as “raft-wood” or “monkey’s comb”, is popularly used as an antirheumatic, antispasmodic and expectorant agent, although its toxic effects are unknown. The objective of this research was therefore to investigate the potential acute toxicity to female mice and rats of a water extract of A. tibourbou leaves (WET), administered by gavage, following OECD Guideline 423/2001 and hippocratic screening. The female mice were divided into three groups of three animals each (C1 – control, given 0.25 mL filtered water; C2 – treated with 300 mg/kg WET; C3 – with 2000 mg/kg WET). The female rats were divided into two groups of three animals each (R1 – control, given 0.5 mL filtered water; R2 – 2000 mg/kg WET). Group C2 consumed 28% more water than group C1 (p < 0.05); group C3 produced 31% more excreta than group C1 (p < 0.0001); group R2 reduced food consumption and excretion by 20% and 28%, relative to group R1 (p < 0.05), respectively. During the Hippocratic screening, no motor and/or sensorial alterations were observed. Neither death nor symptoms of impending death were observed in any animals. It can be concluded that WET has an estimated LD50greater than 2000 mg/kg (Class 5 toxicity, according to the UN Globally Harmonized System – GHS), demonstrating low acute toxicity potential.

New Meliolaceae from the Brazilian Atlantic forest 2: species on host families Annonaceae, Cecropiaceae, Meliaceae, Piperaceae, Rubiaceae, Rutaceae and Tiliaceae.

Continuing the study of black mildews in fragments of the Atlantic forest, three new species and five new records are described herein. Irenopsis luheae-grandiflorae, Meliola vicosensis and Meliola xylopia-sericiae are new species. Cecropia hololeuca, Piper gaudichaudianum and Trichilia lepidota are new hosts for Asteridiella leucosykeae, Asteridiella glabroides and Meliola trichiliae respectively. Asteridiella obesa and Meliola psychotriae var. chiococcae are reported for the first time from Brazil. The new species are described and illustrated based on light and scanning electron microscopy and tables with main characteristics of morphologically similar specimens with species collected in Viçosa are provided. Other species belonging to Meliolaceae collected on hosts belonging to the Annonaceae, Meliaceae and Tiliaceae in Brazil also were studied.

5-Hydroxy-7-methoxyflavone inhibits N-formyl-L-methionyl-L-leucyl-L-phenylalanine-induced superoxide anion production by specific modulate membrane localization of Tec with a PI3K independent mechanism in human neutrophils.

Respiratory burst mediates crucial bactericidal mechanism in neutrophils. However, undesirable respiratory burst leads to pathological inflammation and tissue damage. This study investigates the effect and the underlying mechanism of 5-hydroxy-7-methoxyflavone (MCL-1), a lignan extracted from the leaves of Muntingia calabura L. (Tiliaceae), on N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP)-induced respiratory burst and cathepsin G release in human neutrophils. Signaling pathways regulated by MCL-1 to oppose fMLP-induced respiratory burst were evaluated by membrane localization of Tec induced by fMLP and by immunoblotting analysis of downstream phosphorylation targets of Tec. Briefly, MCL-1 specific inhibited fMLP-induced superoxide anion production in a concentration-dependent (IC(50)=0.16±0.01 µM) and Tec kinase-dependent manner, however, MCL-1 did not affect fMLP-induced cathepsin G release. Further, MCL-1 suppressed fMLP-induced Tec translocation from the cytosol to the inner leaflet of the plasma membrane, and subsequently activation of phospholipase Cγ2 (PLCγ2). Moreover, MCL-1 attenuated PLCγ2 activity and intracellular calcium concentration notably through extracellular calcium influx. Consequently, fMLP-induced phosphorylation of protein kinase C (PKC) and membrane localization of p47(phox) were decreased by MCL-1 in a Tec-dependent manner, while the phosphorylation of extracellular signal-regulated kinase (ERK), p38, AKT and Src tyrosine kinase family remained unaffected. In addition, MCL-1 neither inhibited NADPH oxidase activity nor increased cyclicAMP levels. MCL-1 specific opposes fMLP-mediated respiratory burst by inhibition of membrane localization of Tec and subsequently interfered with the activation of PLCγ2, protein kinase C, and p47(phox).

Antimicrobial activity of the extracts from Benchalokawichian remedy and its components.

BACKGROUND: Infectious diseases cause serious health problems worldwide due to multiresistant bacterial strains. Thai traditional formula such as Benchalokawichian remedy has been used to relieve fever, common cold and influenza. The remedy has been scientifically proved for antipyretic and antiseptic activities. However; the remedy and its components have not been fully studied for antimicrobial activity against pathogenic bacteria. OBJECTIVE: To determine antimicrobial activity of extracts from Benchalokawichian remedy and its components against clinical isolates by disk diffusion method. MATERIAL AND METHOD: The bacterial strains used in the present study were clinical isolates from Thammasat Hospital, Thailand. The ethanolic and water extracts of Benchalokawichian remedy and its components were screened for antimicrobial activity. The tests were performed in triplicate. The results were recorded by measuring diameter of growth inhibition zone. Means +/- SD of the obtained results were calculated. RESULTS: The results of antimicrobial activity demonstrated that the ethanolic extracts of Benchalokawichian remedy and its components were effective against Candida albicans, Gram positive and Gram negative bacteria except some isolates. Tiliacora triandra and Clerodendrum petasites exhibited the most effective antimicrobial activity among other ethanolic extracts. The water extracts of Capparis micracantha, Tiliacora triandra and Harrisonia perforata were able to inhibit the tested strains. Both etahnolic and water extracts of Tiliacora triandra were the only one component of Benchalokawichian remedy that could inhibit the growth of C. albicans. CONCLUSION: The present study provides basic knowledge of the antimicrobial activity of Benchalokawichian remedy and its components. Tiliacora triandra and Clerodendrum petasites were the most effective antimicrobial activity among other ethanolic extracts. They are potential candidates to produce medicinal formula for alternative medicine. Further study on minimum inhibitory concentration and minimum bactericidal concentration assay will be carried out in order to obtain more detailed insightful knowledge to develop medicinal products for treatment of bacterial infection and other infectious diseases.

Specificity between Neotropical tree seedlings and their fungal mutualists leads to plant-soil feedback.

A growing body of evidence obtained largely from temperate grassland studies suggests that feedbacks occurring between plants and their associated soil biota are important to plant community assemblage. However, few studies have examined the importance of soil organisms in driving plant-soil feedbacks in forested systems. In a tropical forest in central Panama, we examined whether interactions between tree seedlings and their associated arbuscular mycorrhizal fungi (AMF) lead to plant-soil feedback. Specifically, do tropical seedlings modify their own AMF communities in a manner that either favors or inhibits the next cohort of conspecific seedlings (i.e., positive or negative feedback, respectively)? Seedlings of two shade-tolerant tree species (Eugenia nesiotica, Virola surinamensis) and two pioneer tree species (Luehea seemannii, Apeiba aspera) were grown in pots containing identical AMF communities composed of equal amounts of inoculum of six co-occurring AMF species. The different AMF-host combinations were all exposed to two light levels. Under low light (2% PAR), only two of the six AMF species sporulated, and we found that host identity did not influence composition of AMF spore communities. However, relative abundances of three of the four AMF species that produced spores were influenced by host identity when grown under high light (20% PAR). Furthermore, spores of one of the AMF species, Glomus geosporum, were common in soils of Luehea and Eugenia but absent in soils of Apeiba and Virola. We then conducted a reciprocal experiment to test whether AMF communities previously modified by Luehea and Apeiba differentially affected the growth of conspecific and heterospecific seedlings. Luehea seedling growth did not differ between soils containing AMF communities modified by Luehea and Apeiba. However, Apeiba seedlings were significantly larger when grown with Apeiba-modified AMF communities, as compared to Apeiba seedlings grown with Luehea-modifed AMF communities. Our experiments suggest that interactions between tropical trees and their associated AMF are species-specific and that these interactions may shape both tree and AMF communities through plant-soil feedback.

In vitro antimicrobial activity of extracts and compounds of some selected medicinal plants from Cameroon.

AIM OF THE STUDY: Seven extracts and eight compounds from four selected Cameroonian medicinal plants, Solanecio mannii Hook f. (Asteraceae), Monodora myristica Dunal (Annonaceae), Albizia gummifera (J.F. Gmel) C.A. Smith (Fabaceae/Mimosoideae) and Glyphaea brevis (Spreng) Monachino (Tiliaceae), traditionally used for the treatment of hepatitis, parasites and other infectious diseases, were tested in vitro for their antimicrobial activity against Gram-positive (5 species) and Gram-negative (4 species) bacteria species and pathogenic yeasts (2 Candida species), to establish whether or not they have antimicrobial activity and to validate scientifically their use in traditional medicine. MATERIALS AND METHODS: The agar disc diffusion and the microbroth dilution methods were used to determine the zone of inhibition between the edge of the filter paper and the edge of the inhibition area (IZ) and the minimal inhibitory concentration (MIC) respectively. RESULTS: The most active extracts against Candida albicans and Candida krusei were respectively the cyclohexane extract from the fruits of Monodora myristica and the ethyl acetate extract from the stem bark of Albizia gummifera (MIC=6.3 microg/ml for both extracts). The lowest MIC value (1.6 microg/ml) for purified compounds was obtained on Candida albicans with a mixture of linear aliphatic primary alcohols (n-C24H50O to n-C30H62O), with n-hexacosanol (1b) as major compound and mixture of fatty acid esters of diunsaturated linear 1,2-diols (6). CONCLUSION: These results afford ground informations for the potential use of the crude extracts of these species as well as of some of the isolated compounds in bacterial and fungal infections.

Activation of nitric oxide/cGMP/PKG signaling cascade mediates antihypertensive effects of Muntingia calabura in anesthetized spontaneously hypertensive rats.

We previously reported that the leaf extract of Muntingia calabura L. (Tiliaceae) exerts a potent hypotensive effect in the normotensive rats. The antihypertensive activity of this plant extract, however, is currently unknown. In the present study, we investigated the antihypertensive effects of the n-butanol soluble fraction (BSF) from methanol leaf extract of M. calabura in spontaneously hypertensive rats (SHR), and delineated is underlying mechanisms. The intravenous bolus administration of the BSF (10-100 mg/kg) of M. calabura produced biphasic dose-related antihypertensive and bradycardiac effects in SHR. The BSF-induced initial cardiovascular depressive effects lasted for 10 min, and the delayed effects commenced 40 min and lasted for at least 120 min postinjection. These cardiovascular depressive effects of BSF treatments were greater in SHR than in normotensive Wistar-Kyoto (WKY) rats. Both the initial and delayed antihypertensive and bradycardiac effects of BSF (25 mg/kg, i.v.) in SHR, were significantly blocked by pretreatment with a nonselective nitric oxide (NO) synthase (NOS) inhibitor, a soluble guanylyl cyclase (sGC) inhibitor, or a protein kinase G (PKG) inhibitor. Moreover, the initial effects of BSF in SHR were inhibited by pretreatment with a selective endothelial NOS (eNOS) inhibitor; whereas the delayed effects were attenuated by a selective inducible NOS (iNOS) inhibitor. These results indicate that the BSF from the leaf of M. calabura elicited both transient and delayed antihypertensive and bradycardiac actions in SHR, which might be mediated through NO generated respectively by eNOS and iNOS. Furthermore, activation of sGC/cGMP/PKG signaling pathway may participate in the M. calabura-induced biphasic cardiovascular effects.

[Study on the enrichment and purification of total flavonoids in Microcos paniculata by macroporous adsorption resin].

OBJECTIVE: To establish an optimum enrichment and purification process of total flavonoids in Microcos paniculata by macroporous resins. METHODS: Five kinds of resins were compared and the best one was chosen. Then the parameters of the process were optimized by single factor tests, uniform design and statistical methods. RESULTS: DI01 was selected for its excellent adsorption and desorption properties, 70% ethanol was found to be the best elution solution. As far as the yield was considered, the best result was based on the followings: feed rate-1.0 BV/h, elution flow rate-2.0 BV/h, sample concentration-7.88 mg/mL, eluting agent amount-2.0 BV, pH value 4.8; then the yield reached 90.18% and the purity was 54.37%. If the purity was considered, the best parameters wereas follows: feed rate-1.0 BV/h, elution flow rate-2.0 BV/h, sample concentration-2.0 mg/mL, eluting agent amount-2.8 BV, pH value 7.8; then the purity reached 61.77% and the yield was 80.25%. CONCLUSION: The total flavonoids of Microcos paniculata can be effectively purificated and separated by D101 macroporous resin.

[Seperation and structure elucidation of alkaloids from Chinese drug buzhaye, Folium Microcos].

From the chloroform extracts of the dried Folium Microcos, four compounds were isolated by using repeated column chromatography on silica gel and recrystallization and their structures were elucidated by physicochemical properties and UV, MS and NMR, separately. They are N-methyl-6alpha-(deca-1', 3', 5'-trienyl)-3beta-methoxy-2beta-methylpiperidine, 6-(deca-1', 3', 5'-trienyl)-3-methoxy-2-methylpiperidine, N-methyl-6-(deca-1', 3', 5'-trienyl)-2, 3-dimethylpiperidine and N-methyl-6-(deca-1', 3', 5'-trienyl)-2-methylpiperidine, named as micropiperidine A, micropiperidine B, micropiperidine C and micropiperidine D, respectively. The latter three are new compounds.

Seperation and structure elucidation of alkaloids from Chinese drug buzhaye, Folium Microcos / 药学学报

From the chloroform extracts of the dried Folium Microcos, four compounds were isolated by using repeated column chromatography on silica gel and recrystallization and their structures were elucidated by physicochemical properties and UV, MS and NMR, separately. They are N-methyl-6alpha-(deca-1', 3', 5'-trienyl)-3beta-methoxy-2beta-methylpiperidine, 6-(deca-1', 3', 5'-trienyl)-3-methoxy-2-methylpiperidine, N-methyl-6-(deca-1', 3', 5'-trienyl)-2, 3-dimethylpiperidine and N-methyl-6-(deca-1', 3', 5'-trienyl)-2-methylpiperidine, named as micropiperidine A, micropiperidine B, micropiperidine C and micropiperidine D, respectively. The latter three are new compounds.

Two new piperidine alkaloids from the leaves of Microcos paniculata.

Two new piperidine alkaloids, microcosamines A (1) and B (2), were isolated from the leaves of Microcos paniculata. Their structures were elucidated by spectroscopic analysis. Both new compounds showed significant larvicidal activity against Culex quinquefasciatus.

New dihydrochalcones and anti-platelet aggregation constituents from the leaves of Muntingia calabura.

Two new dihydrochalcones, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone (1) and 4,2',4'-trihydroxy-3'-methoxydihydrochalcone (2), and a new flavanone, (2R,3R)-(-)-3,5-dihydroxy-6,7-dimethoxyflavanone (3), together with nineteen known compounds have been isolated from the leaves of Muntingia calabura. The structures of three new compounds were determined through spectral analyses including extensive 2D-NMR data. Among the isolates, 2,3-dihydroxy-4,3',4',5'-tetramethoxydihydrochalcone, 5,7-dihydroxy-3-methoxyflavone, 5,7-dihydroxy-6-methoxyflavone, 5,4'-dihydroxy-3,7-dimethoxyflavone, (2S)-7,8,3',4',5'-pentamethoxyflavan, (2S)-5'-hydroxy-7,8,3',4'-tetramethoxyflavan, and methyl gallate exhibited significant anti-platelet aggregation activity in vitro.

Characterization of lignin isolated from some nonwood available in Bangladesh.

Lignins isolated from cotton stalks, jute stick and dhaincha by acidolytic dioxane were characterized using alkaline nitrobenzene oxidation, elemental analysis, methoxyl analysis and molecular weight analysis and UV, IR (1)H NMR spectroscopy. The C(9) formulas for cotton stalks, jute stick and dhaincha (Sesbania aculeata) lignin were C(9)H(9.36)O(4.50)(OCH(3))(1.23), C(9)H(9.02)O(4.57)(OCH(3))(1.35) and C(9)H(8.88)O(4.65)(OCH(3))(1.50), respectively. All three lignins were of the guaiacyl-syringyl type. Cotton stalks lignin contained more p-hydroxy phenyl unit than dhaincha and jute stick lignins as observed by alkaline nitrobenzene oxidation products. The beta-O-4 units in these nonwood lignins had predominately erythro stereochemistry type.