刺桐化学成分的研究

目的研究刺桐E ry thrina varieg a ta茎皮的化学成分。方法采用硅胶、Sephadex LH-20柱色谱分离化合物,运用波谱技术分析确定化学结构。结果从刺桐茎皮65%乙醇提取物的醋酸乙酯萃取层中分离得到9个化合物,利用理化性质及波谱分析确定其结构分别为:5,4′-二羟基-8-(3,3-二甲基烯丙基)-2,″2″-二甲基吡喃[5,6∶6,7]异黄酮(Ⅰ)、豆甾醇(Ⅱ)、erythrinas inate B(Ⅲ)、3-羟基-2,′2′-二甲基吡喃[5,6∶9,10]紫檀烷(Ⅳ)、5,7-二羟基-8-(3,3-二甲基烯丙基)-二氢黄酮(Ⅴ)、5,4′-二羟基-2,″2″-二甲基吡喃[5,6∶6,7]异黄酮(Ⅵ)、5,7,4′-三羟基-6,8-二(3,3-二甲基烯丙基)异黄酮(Ⅶ)、5,2,′4′-三羟基-8-(3,3-二甲基烯丙基)-2,″2″-二甲基吡喃[5,6∶6,7]异黄酮(Ⅷ)、5,4′-二羟基-6-(3,3-二甲基烯丙基)-2,″2″-二甲基吡喃[5,6∶7,8]异黄酮(Ⅸ)。结论化合物Ⅰ、Ⅲ、Ⅳ、Ⅶ、Ⅸ为首次从该植物中分离得到,化合物Ⅴ为首次从该属植物中分离得到。     

Isoprenylated flavonoids from the stem bark of Erythrina abyssinica

Three new prenylated flavanones, abyssinoflavanones V, VI, and VII (1-3), together with eight known flavanones (4-11) and two chalcones (12-13), were isolated from the stem bark of Erythrina abyssinica. Their structures were elucidated on the basis of spectroscopic and physicochemical analyses. All the isolates, with the exception of 1 and 8, strongly inhibited PTP1B activity in an in vitro assay with IC50 values ranging from 14.2 +/- 1.7 to 26.7 +/- 1.2 microM.     

Biologically active prenylated flavonoids from the genus Sophora and their structure–activity relationship—A review

The genus Sophora (Fabaceae) has been used in traditional medicine for years. Prenylated flavonoids are one of the constituents of Sophora species that play important roles in their biological properties. Different classes of prenylated flavonoids are produced by Sophora spp. including prenylated flavonol (e.g., sophoflavescenol), prenylated flavanone (e.g., sophoraflavanone G), prenylated flavonostilbene (e.g., alopecurones A and B), and prenylated chalcone (kuraridin). Prenylated flavonoids have a more lipophilic structure, which leads to its high affinity to the cell membranes and enhancement of the biological activity, which includes cytotoxicity, antibacterial, anti‐inflammatory, and estrogenic activities. However, it is reported that prenylation decreases the plasma absorption but increases the tissue accumulation. The presence of the prenyl or lavandulyl groups on C8 position of flavonoids plays an important role in the biological activity. It seems that prenylated flavonoids have the potential to be developed as new drugs or supplements for human health.     

Cytotoxic flavonoids from the stem bark of Lonchocarpus aff. fluvialis

Activity-guided fractionation of a chloroform-soluble extract of Lonchocarpus aff. fluvialis stem bark using a human epidermoid (KB) tumour cell line as a monitor afforded five rotenoids, one pterocarpan, one chalcone, three flavanones, one flavone and one triterpenoid. All of the compounds isolated proved to be of previously known structure. Among them, the rotenoids (-)-sumatrol and (+/-)-villosinol, the dibenzoylmethane derivative (+)-3,4-methylenedioxy-2'-methoxy-[2",3":4',3']-furanodibenzoylmethane, and the flavanones (-)-isoglabrachromene and (-)-candidone have been shown to exhibit significant cytotoxic activity against human cancer cells for the first time. This is the first report of the chemical constituents of this species, and the profile of compounds obtained was in accordance with the established chemosystematic patterns of species in the tribe Tephrosieae (Leguminosae, Papilionoideae).     

Anticonvulsant activity of hydroalcoholic extracts from Erythrina velutina and Erythrina mulungu

The anticonvulsant effects of hydroalcoholic extracts (HAEs) from the stem bark of Erythrina velutina and Erythrina mulungu on pentylenetetrazole (PTZ) and strychnine-induced seizure tests and the potentiation of pentobarbital-induced sleeping time in mice with the extracts were examined in this study. These medicinal plants belong to the Fabaceae family and are popularly used in Brazil for their effects on the central nervous system. The extracts of Erythrina velutina (intraperitoneally or orally) and Erythrina mulungu (intraperitoneally) were administered in mice at single doses (200 or 400mg/kg). While Erythrina velutina and Erythrina mulungu did not exhibit any protector effect in PTZ-induced seizures, at any dose, an increase in the latency of convulsion and in the death time was observed with both doses and routes of Erythrina velutina and at higher dose of Erythrina mulungu, in strychnine-induced seizure. No alteration was observed with Erythrina velutina and Erythrina mulungu on sleeping latency at both doses as compared to control (362.8+/-59.5). However, the sleeping time was increased in both plants as compared to control (943.8+/-129.6). In conclusion, we showed that the hydroalcoholic extracts of Erythrina velutina and Erythrina mulungu have anticonvulsant effects only in the strychnine-induced seizure model, suggesting their possible action in glycine system and a potentiation of pentobarbital sleeping time, suggesting depressant action in the central nervous system.     

The genus Erythrina L.: A review on its alkaloids,preclinical, and clinical studies

Erythrina L. genus (Fabaceae) comprises about 115 species, and it has been extensively studied, mainly because of its alkaloids, which have pharmacological properties. References demonstrated that Erythrina spp. have a potential to act in the central nervous system, presenting anxiolytic and anticonvulsant properties already established. Phytochemical investigations confirmed the presence of tetracyclic alkaloids as the major compounds. However, other alkaloid classes have also been reported, including dimeric and trimeric substances, coupled through direct polymerization or two erythrinine units via an acetyl glucose. The present review covers the relevant literature from 1990 until 2017 and outlines the current data on chemical composition and preclinical and clinical studies on Erythrina species. Additionally, the quite striking analogy in the biosynthetic route of erythrin, morphinans, and Amaryllidaceae family alkaloids was also discussed.     

Antibacterial activity of flavonoids and their structure–activity relationship: An update review

Based on World Health Organization reports, resistance of bacteria to well‐known antibiotics is a major global health challenge now and in the future. Different strategies have been proposed to tackle this problem including inhibition of multidrug resistance pumps and biofilm formation in bacteria and development of new antibiotics with novel mechanism of action. Flavonoids are a large class of natural compounds, have been extensively studied for their antibacterial activity, and more than 150 articles have been published on this topic since 2005. Over the past decade, some promising results were obtained with the antibacterial activity of flavonoids. In some cases, flavonoids (especially chalcones) showed up to sixfold stronger antibacterial activities than standard drugs in the market. Some synthetic derivatives of flavonoids also exhibited remarkable antibacterial activities with 20‐ to 80‐fold more potent activity than the standard drug against multidrug‐resistant Gram‐negative and Gram‐positive bacteria (including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus). This review summarizes the ever changing information on antibacterial activity of flavonoids since 2005, with a special focus on the structure–activity relationship and mechanisms of actions of this broad class of natural compounds.     

Antibacterial activity of flavonoids and phenylpropanoids from Marrubium globosum ssp. libanoticum

Marrubium globosum Montbr. et Auch. ex Benth. ssp. libanoticum Boiss. (Lamiaceae) is a medicinal plant used for the treatment of inflammatory diseases, asthma, coughs and other pulmonary and urinary problems. The goal of our study was to assess the biological activity of M. globosum testing the methanol extract of aerial parts for its antibacterial activity against bacteria known to cause respiratory, gastrointestinal, skin and urinary disorders; the extract showed antibacterial effects against all the strains of bacteria used. A purification of this active extract showed the presence, as main constituents, of verbascoside, isorhamnetin 3-O-beta-D-rutinoside, quercetin 3-O-beta-D-rutinoside, naringenin 7-O-beta-D-glucoside, kaempferol 3-O-beta-D-rutinoside, isorhamnetin 3-O-beta-D-glucoside, quercetin 3-O-beta-D-glucoside, apigenin 7-O-(3'-p-coumaryl)-glucoside, p-methoxy-cinnamic acid, kaempferol 3-O-beta-D-glucoside and apigenin 7-O-beta-D-glucoside. The pure compounds were tested for their antibacterial activity; quercetin 3-O-beta-D-rutinoside, verbascoside and naringenin 7-O-beta-D-glucoside showed the greatest activity.     

Acute and subchronic oral toxicity assessment of the aqueous extract from the stem bark of Erythrina senegalensis DC (Fabaceae) in rodents

Aim of the study

The decoction of the stem bark of Erythrina senegalensis (EAES) is traditionally used in the Western region of Cameroon against liver disorders. The present study evaluated the potential toxicity of this decoction after acute and sub-chronic administration in rodents.

Materials and methods

In acute study, a single administration of EAES was given orally to mice at doses ranging from 1.25 to 12.5 g/kg. General behaviour, adverse effects and mortality were determined for up to 14 days post treatment. In the sub-chronic study, EAES was given orally as a single administration to Wistar rats at doses of 300, 600 and 1200 mg/kg/day for 28 days. Animal body weight was observed throughout the experimental period while haematological and biochemical parameters of blood and urine, as well as kidney and liver tissues histology were evaluated at the end of the experiment.

Results

In the acute study in mice, none of the doses used induced mortality or significant behavioural changes. In the sub-chronic study in rats, daily oral administration of EAES at the dose of 600 mg/kg resulted in a significant increase in the relative body weight at the last week of treatment. The relative weights of organs were not affected by the treatment. No haematological changes were observed a part of a significant increase in WBC count at the dose of 600 mg/kg. Serum AST, ALT, ALP, total protein, total cholesterol and triglycerides decreased significantly while total and conjugated bilirubin significantly increased. Renal function indices assay in blood showed significant modification in all the treated groups compared to control while, in urine, only urea excretion markedly reduced at a dose of 1200 mg/kg. Histological analysis did no show any liver or kidney alteration.

Conclusion

These results demonstrated that there is a wide margin of safety for the therapeutic use of EAES and further corroborated the traditional use of this extract as a hepatoprotective agent.     

桑属植物中异戊烯基黄酮类化合物及其药理活性研究进展

桑科桑属植物在我国分布广泛,其枝、叶、根皮、果实均可入药,具有很高的药用价值。目前从桑属植物中分离得到的化学成分有黄酮、生物碱、香豆素、萜类、多糖等,其中异戊烯基黄酮类化合物为其特征成分,具有抗菌、抗炎、抗肿瘤、抗病毒、降血压、降血糖、抗氧化等多种药理活性。主要对桑属植物中异戊烯基黄酮类化合物及其药理活性的研究进展进行综述,为桑属植物的开发利用和药效物质研究提供参考。     

Erythrina alkaloids and a pterocarpan from the bark of Erythrina subumbrans

Three new erythrina alkaloids, (+)-10,11-dioxoerythratine (1), (+)-10,11-dioxoepierythratidine (2), and (+)-10,11-dioxoerythratidinone (3), and a new pterocarpan, 1-methoxyerythrabyssin II (4), were isolated from the bark of Erythrina subumbrans, together with seven known pterocarpans, erythrabyssin II, erybraedin A, erystagallin A, erycristagallin, erythrabissin-1, eryvarin A, and hydroxycristacarpone, three flavanones, 5-hydroxysophoranone, abyssinone V, and lespedezaflavanone B, three triterpenes, sophoradiol, soyasapogenol B, and lupeol, and one isoflavanone, vogelin C. Their structures were elucidated on the basis of spectroscopic data. Some isolates were tested for antiplasmodial, antimycobacterial, and cytotoxic activities.     

Antibacterial steroid alkaloids from the stem bark of Holarrhena pubescens

Holarrhena pubescens (syn. H. antidysenterica) (L.) WALL. stem bark was tested for antibacterial efficacy against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa using the microdilution broth method as well as the disc diffusion method. The crude methanolic extract was active against all tested bacteria. Further chemical fractionation indicated that the antibacterial activity was mainly associated with the alkaloids. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for the crude extract, the total alkaloids and the neutral fraction using microdilution broth method. The results were compared with reference antibiotics. The total alkaloids showed remarkable activity against S. aureus (MIC = 95 microg/ml).     

Cyclooxygenase inhibitory flavonoids from the stem bark of Semecarpus anacardium Linn

The ethyl acetate extract of stem bark of Semecarpus anacardium showing in vivo anti-in fl ammatory activity in carrageenan induced rat paw edema assay was investigated in order to identify its active compounds. Chemical investigation of the ethyl acetate extract of S.anacardium afforded 3,4,2',4'-tetrahydroxychalcone (butein) and 7,3',4'-trihydroxy fl avone. Evaluation of COX-1 inhibitory activity of 3,4,2',4'-tetrahydroxychalcone and 7,3',4'-trihydroxy fl avone provided the IC(50) values of 28.4 and 36.7 micro M respectively. Further investigation of these compounds for COX-2 inhibitory activity revealed moderate potency towards this enzyme.     

Inhibition of phospholipase C activity by auriculatin and 8-prenylluteone isolated from Erythrina senegalensis

Auriculatin and 8-prenylluteone were isolated from Erythrina senegalensis (Leguminosae) as inhibitors of phospholipase C (PLC) and phosphoinositides (PI)-turnover in PLC-γ1 overexpressing NIH3T3 fibroblasts (NIH3T3γ1). Auriculatin (1) and 8-prenylluteone (2) showed inhibitory activity with an IC₅₀ value of 20 μm on PLC in vitro as well as the formation of inositol phosphates in platelet-derived growth factor (PDGF)-stimulated NIH3T3γ1 cells. They also showed a moderate cytotoxicity against several human tumour cell lines with an IC₅₀ of 9.0–20 μm , i.e. PC-3 (prostate), NCI-H226 (lung), CRL1579 (melanoma) in vitro. © 1998 John Wiley & Sons, Ltd.     

Antibacterial activity studies of flavonoids from Salvia palaestina

Ten aglycones and six glycosides of luteolin and apigenin were identified from the leaves of Salvia palaestina Bentham (Labiatae). Among them cirsimaritin showed a high activity against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Pseudomonas aeruginosa, while the others have little or no activity against the same bacterial strains.     

Antibacterial activity of essential oils from Australian native plants

To date, of the Australian essential oils, only tea tree (Melaleuca alternifolia) and Eucalyptus spp. have undergone extensive investigation. In this study a range of Australian essential oils, including those from Anethole anisata, Callistris glaucophyllia, Melaleuca spp. and Thyptomine calycina, were assayed for in vitro antibacterial activity. M. alternifolia was also included for comparison purposes. Activity was determined using standard disc diffusion assays with each oil assayed at 100%, 10% and 1% against five bacteria (Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Pseudomonas aeruginosa and Alcaligenes faecalis) and the yeast, Candida albicans. All bacteria, with the exception of Ps. aeruginosa, were susceptible to one or more of the essential oils at 100%, with only Eremophilia mitchelli inhibiting the growth of any bacteria at 1% (inhibition of Sal. typhimurium). Where multiple samples of a single oil variety were tested variability in activity profiles were noted. This suggests that different methods of preparation of essential oils, together with variability in plant chemical profiles has an impact on whether or not the essential oil is of use as an antimicrobial agent. These results show that essential oils from Australian plants may be valuable antimicrobial agents for use alone or incorporated into cosmetics, cleaning agents and pharmaceutical products.     

Antiparasitic activity of C-geranyl flavonoids from Mimulus bigelovii

Bioactivity‐directed fractionation of the MeOH fraction of the extract of Mimulus bigelovii by means of an axenic Leishmania amastigote assay and chromatographic techniques resulted in the isolation of four C‐geranyl flavanones, diplacone (1), 3′‐O‐methyldiplacone (2), 4′‐O‐methyldiplacone (3), 3′‐O‐methyldiplacol (4), together with a geranylated flavone, cannflavin A (5). These compounds were separated from M. bigelovii for the first time. All compounds showed moderate antileishmanial activity against axenic Leishmania donovani amastigotes with IC₅₀ values ranging from 4.8 to 14.6 μg/mL. The compounds were also tested against the related kinetoplastid parasite Trypanosoma brucei brucei and they showed activity with IC₅₀ values ranging from 1.4 to 7.2 μg/mL. Copyright © 2011 John Wiley & Sons, Ltd.     

毛茛属药用植物中黄酮和内酯类成分的研究进展

我国毛茛属药用植物资源丰富,医药前景良好。目前研究发现毛茛属药用植物中主要含有黄酮和内酯类成分,药理活性主要表现为抗肿瘤、抗菌和抗炎,并对心血管系统也有一定的影响。主要对近年来毛茛属药用植物的黄酮和内酯类化学成分的研究进行了综述,希望能够有助于毛茛属药用植物的开发和利用。     

Antibacterial activity of Marula (Sclerocarya birrea (A. rich.) Hochst. subsp. caffra (Sond.) Kokwaro) (Anacardiaceae) bark and leaves.

Marula bark is widely used for bacteria-related diseases by indigenous cultures in Africa. This study was undertaken to investigate whether the ethnobotanical use can be validated by laboratory studies. Bark and leaves were extracted with acetone and MIC values were determined using a microplate serial dilution technique with Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis as test organisms. All extracts were active with MIC values from 0.15 to 3 mg/ml. Based on minimum inhibitory concentration values, inner bark extracts tended to be the most potent followed by outer bark and leaf extracts, but the differences were not statistically significant. There were two major bioactive components visible after bioautography of leaf extracts: one strongly polar and the other highly non-polar. The bioactive components could be separated from 92% of the non-active dry matter by solvent-solvent fractionation into the carbon tetrachloride, chloroform and n-butanol fractions; these fractions, however, still contained many different compounds. Using bark may be detrimental to the plant, but leaf material can also be used for antibacterial application.     

Anti-cancer activity of compounds from Bauhinia strychnifolia stem

Ethnopharmacological relevance

The stem and root of Bauhinia strychnifolia Craib (Fabaceae family) have been traditionally used in Thailand to treat fever, alcoholic toxication, allergy and cancer. An EtOH extract of Bauhinia strychnifolia showed good inhibitory activity against several cancer cell lines including HT-29, HeLa, MCF-7 and KB. As there has been no previous reports on chemical constituents of Bauhinia strychnifolia, this study is aimed to isolate the pure compounds with anti-cancer activity.

Materials and methods

Five pure compounds were isolated from EtOH extract of Bauhinia strychnifolia stem using silica gel, dianion HP-20 and sephadex LH-20 column chromatography and were tested for their cytotoxic effects against HT-29, HeLa, MCF-7 and KB cell lines using the Sulforhodamine B (SRB) assay.

Results

Among five compounds, 3,5,7,3′,5′-pentahydroxyflavanonol-3-O-α-l-rhamnopyranoside (2) possessed very potent activity against KB (IC₅₀=0.00054 μg/mL), HT-29 (IC₅₀=0.00217 μg/mL), MCF-7 (IC₅₀=0.0585 μg/mL) and HeLa cells (IC₅₀=0.0692 μg/mL). 3,5,7-Trihydroxychromone-3-O-α-l-rhamnopyranoside (3) also showed good activity against HT-29 (IC₅₀=0.02366 μg/mL), KB (IC₅₀=0.0412 μg/mL) and MCF-7 (IC₅₀=0.297 μg/mL), respectively. The activity of 2 (IC₅₀=0.00054 μg/mL) against KB cell was ten times higher than that of the positive control, Camptothecin (anti-cancer drug, IC₅₀=0.0057 μg/mL). All compounds did not show any cytotoxicity with normal cells at the concentration of 1 μg/mL.

Conclusion

This is the first report of compounds 2 and 3 on anti-cancer activity and based on the anti-cancer activity of extracts and pure compounds isolated from Bauhinia strychnifolia stem, it might be suggested that this plant could be useful for treatment of cancer.