Antimicrobial activities of Barringtonia acutangula

Crude extracts and VLC fractions from the stem bark of Barringtonia acutangula (L.) Gaertn (Fam. Lecythidaceae) were screened for their antimicrobial activities against two Gram-positive bacteria, two Gram-negative bacteria and two fungi using a microdilution titre assay. Among the crude extracts, petroleum ether extract showed good activity against all test organisms. The VLC fraction PE 16 was found to be very effective against Bacillus subtilis (MIC=25 microg/ml) and Aspergillus niger (MIC=12.5 microg/ml). The activities were compared to standard antibiotics-kanamycin and fluconazole. The major compound from PE16 was identified as 12, 20(29)-lupadien-3-ol by NMR spectroscopy.     

Barringtonia acutangula improves the biochemical parameters in diabetic rats简

AIM： This study was aimed at evaluating the anti-diabetic activity of the ethanol and aqueous extracts of the leaf material of Bar- ringtonia acutangula in a diabetic animal model. METHODS： The ethanolic and aqueous extracts （250 and 500 mg＇kg-1 body weight） of the leaves ofB. acutangula were assessed for antidiabetic activity in a streptozotocin （STZ）-induced diabetes animal model following 21 days of treatment. Glibenclamide （0.6 mg＇kg-1 p.o.） was used as a positive control. The hematological parameters, such as blood glucose level, urea, creatinin, cho- lesterol, HDL-C, and LDL-C levels were examined. RESULTS： An acute toxicity study （5 000 mg＇kg-1, p.o.） did not produce any symptoms of toxicity. Significant reductions in blood glucose level, and serum total cholesterol and triglyceride levels were noted in animals treated with the extract. The high density lipoprotein-cholesterol （HDLC） level was found to increase as compared with the diabetic control group. CONCLUSION： These results suggest that the leaf aqueous and ethanolic extracts of B. acutangula have anti-diabetic effects. The aqueous extract of B. acutangula produced a similar effect when compared with the ethanol extract. It is proposed that con- sumption of B. acutangula in some form like tea may help the management of diabetes.     

Acylated triterpenoid saponins from the stem bark of Foetidia africana

Nine new acylated triterpenoid saponins (4-12) were isolated from the stem bark of Foetidia africana. They all possess barringtogenol C as the aglycone, esterified by acetic and/or isovaleric acids. The sugar chain consists of up to three units: D-glucuronic acid (GlcUA) linked to C-3 of the aglycone and substituted by D-galactose (Gal) (at GlcUA C-2) and/or L-rhamnose (Rha) (at GlcUA C-4). The structures were established by acid and alkaline hydrolysis, by NMR experiments including (1)H-(1)H (COSY, HOHAHA, ROESY) and (1)H-(13)C (HSQC, HMBC) spectroscopy, and by mass spectrometry (ESIMS, ESIMS(n)).     

Two major saponins from seeds of Barringtonia asiatica: putative antifeedants toward Epilachna sp. larvae

Two major saponins have been isolated from a methanol extract of the seeds of Barringtonia asiatica, and their structures elucidated (mainly by two-dimensional NMR spectroscopy) as 3-O-[[beta-D-galactopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->2)]-beta-D-glucuronopyranosyloxy]-22-O-(2-methylbutyroyloxy)-15,16,28-trihydroxy-(3beta,15alpha,16alpha,22alpha)-olean-12-ene (3) and 3-O-[[beta-D-galactopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->2)]-beta-D-glucuronopyranosyloxy]-22-O-[2(E)-methyl-2-butenyloyloxy]-15,16,28-trihydroxy-(3beta,15alpha,16alpha,22alpha)-olean-12-ene (4). The antifeedant properties of 3 and 4 toward Epilachna larvae are discussed.     

Steroidal saponins from the bark of Dracaena draco and their cytotoxic activities

From the stem bark of Dracaena draco, three new compounds, namely, draconins A-C (1-3), were isolated, along with 17 known compounds. The structures of the new compounds isolated were elucidated on the basis of spectroscopic data interpretation. Several of the isolated compounds showed potent cytotoxic activities measured on the human leukemia cell line HL-60 (IC(50)'s from 2.0 to 9.7 microM at 72 h). The mechanism by which compounds 1 and 2 display their cytostatic properties is through induction of cell death by apoptosis, as evaluated by fluorescence microscopy and DNA fragmentation.     

太白盯木根皮中两个新的齐墩果酸皂苷

目的：对新种太白木（ＡｒａｌｉａｔａｉｂａｉｅｎｓｉｓＺ．Ｚ．ＷａｎｇｅｔＨ．Ｃ．Ｚｈｅｎｇ）根皮的皂苷成分继续进行研究。方法：利用硅胶柱层析和高效液相层析进行分离，根据皂苷的理化性质和光谱数据鉴定其结构。结果：得到３个化合物，分别确定为齐墩果酸２８ＯβＤ吡喃葡萄糖苷（Ⅰ），３ＯβＤ吡喃葡萄糖醛酸丁酯齐墩果酸２８ＯβＤ吡喃葡萄糖苷（Ⅱ）和３ＯβＤ吡喃葡萄糖醛酸癸酯齐墩果酸２８ＯβＤ吡喃葡萄糖苷（Ⅲ）。结论：皂苷Ⅱ和Ⅲ为新化合物，分别命名为太白木皂苷Ⅳ（ｔａｉｂａｉｅｎｏｓｉｄｅⅣ）和太白木皂苷Ⅴ（ｔａｉｂａｉｅｎｏｓｉｄｅⅤ），皂苷Ⅰ为首次从该植物中分得。     

太白楤木根皮中两个新的齐墩果酸皂苷

 目的:对新种太白楤木(Aralia taibaiensis Z. Z. Wang et H. C. Zheng)根皮的皂苷成分继续进行研究。方法:利用硅胶柱层析和高效液相层析进行分离，根据皂苷的理化性质和光谱数据鉴定其结构。结果:得到3个化合物，分别确定为齐墩果酸-28- O-β-D_吡喃葡萄糖苷(Ⅰ)，3-O-β-D- 吡喃葡萄糖醛酸丁酯-齐墩果酸_28_O-βD-吡喃葡萄糖苷(Ⅱ)和3- O-β-D- 吡喃葡萄糖醛酸癸酯-齐墩果酸-28-O-β-D-吡喃葡萄糖苷( Ⅲ ) 。结论:皂苷Ⅱ和Ⅲ为新化合物，分别命名为太白楤木皂苷Ⅳ ( taibaienoside Ⅳ)和太白楤木皂普Ⅴ( taibaienoside Ⅴ) ,皂苷I为首次从该植物中分得。     

帽蕊木中的喹诺酸三萜皂苷

目的：研究帽蕊木Mitragyna rotundifolia 茎皮的正丁醇部位化学成分。方法：采用各种色谱法分离,运用多种波谱技术鉴定结构。结果：分离鉴定出6个化合物quinovic acid-3-O-β-D-6-Deoxy-glucopyranoside,28-O-β-D-glucopyranosyl ester(1),quinovic acid-27-O-α-L-Rhamnopyranosyl ester(2),quinovic acid-3-O-α-L-Rhamnopyranoside(3),qunovic acid-27-O-β-D-glucopyranosyl ester(4),quovic acid-3-O-β-D-6-Deoxy-glucopyranoside(5),qunovic acid-27-O-β-6-deoxy-D-glucopyranosyl ester(6)。结论：化合物1～6均为首次从该植物中得到,化合物1～4和6为首次从该属中得到。     

Antinociceptive effect and toxicological study of the aqueous bark extract of Barringtonia racemosa on rats

Barringtonia racemosa Linn. (Family Lecythidaceae) possess several bioactivities and is used in traditional medicine of Sri Lanka, but its analgesic potential has not been investigated so far. The aim of this study was therefore to examine the antinociceptive potential of an aqueous bark extract (500, 750, 1000 or 1500 mg/kg) of B. racemosa in male rats using three models of nociception (tail flick, hot plate and formalin tests). The results showed that the extract has antinociceptive activity (when evaluated in hot plate and formalin test but not in tail flick test) without producing unwanted side effects or toxicity. Further, the extract did not alter fertility, gestational length, peri- and neonatal development and appears to be non-teratogenic. The antinociceptive effect was mediated mainly via opioid mechanisms. Such inhibition of pain could arise from phenolic and steroidal constituents as was shown to be present in the extract.     

Trigonosins A-F, daphnane diterpenoids from Trigonostemon thyrsoideum

Phytochemical study of the roots of Trigonostemon thyrsoideum led to the isolation of four new oxygenated daphnane-type diterpenoids, trigonosins A-D (1-4), and two new modified daphnanes, trigonosins E and F (5 and 6). The structures and relative configurations were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D NMR experiments. All compounds isolated were evaluated for their cytotoxicity against HL-60, A549, and MCF-7 human cancer cell lines.     

Gymnasterkoreaynes A-F,cytotoxic polyacetylenes from Gymnaster koraiensis

Six new polyacetylenes, gymnasterkoreaynes A-F (1-6), were isolated from the roots of Gymnaster koraiensis, together with 2,9,16-heptadecatrien-4,6-diyn-8-ol (7) and 1,9,16-heptadecatriene-4,6-diyn-3,8-diol (8), by bioassay-guided fractionation using the L1210 tumor cell line as a model for cytotoxicity. The structures of compounds 1-6 were established spectroscopically, which included 2D NMR experiments. Gymnasterkoreaynes A-F (1-6) are linear diacetylenes and are structurally related to falcarinol, panaxynol, panaxydiol, and panaxytriol. Of the compounds isolated, gymnasterkoreaynes B (2), C (3), F (6), and 1,9,16-heptadecatrien-4,6-diyn-3,8-diol (8) exhibited significant cytotoxicity against L1210 tumor cells with ED(50) values of 0.12-3.3 microg/mL.     

Flacourtosides A-F, phenolic glycosides isolated from Flacourtia ramontchi

In an effort to identify novel inhibitors of chikungunya (CHIKV) and dengue (DENV) virus replication, a systematic study with 820 ethyl acetate extracts of madagascan plants was performed in a virus-cell-based assay for CHIKV, and a DENV NS5 RNA-dependent RNA polymerase (RdRp) assay. The extract obtained from the stem bark of Flacourtia ramontchi was selected for its significant activity in both assays. Six new phenolic glycosides, named flacourtosides A-F (1-6), phenolic glycosides itoside H, xylosmin, scolochinenoside D, and poliothrysoside, and betulinic acid 3β-caffeate were obtained using the bioassay-guided isolation process. Their structures were elucidated by comprehensive analyses of NMR spectroscopic and mass spectrometric data. Even though several extracts and fractions showed significant selective antiviral activity in the CHIKV virus-cell-based assay, none of the purified compounds did. However, in the DENV RNA polymerase assay, significant inhibition was observed with betulinic acid 3β-caffeate (IC(50) = 0.85 ± 0.1 μM) and to a lesser extent for the flacourtosides A and E (1 and 5, respectively), and scolochinenoside D (IC(50) values ~10 μM).     

Phyllanemblinins A-F, new ellagitannins from Phyllanthus emblica.

Six new ellagitannins, phyllanemblinins A-F (1-6), were isolated from Phyllanthus emblica, along with 30 known tannins and related compounds. Their structures were determined by spectral and chemical methods. Phyllanemblinins A (1) and B (2) were confirmed to be ellagitannins having a tetrahydroxybenzofuran dicarboxyl group and a hexahydroxydiphenoyl group, respectively, by chemical synthesis from furosin (8). Phyllanemblinin C (3) has a new acyl group at the glucose 2,4-positions and is structurally related to chebulagic acid. Phyllanemblinins D (4), E (5), and F (6) were found to be positional isomers of neochebuloyl 1(beta)-O-galloylglucose.     

Russujaponols A-F, illudoid sesquiterpenes from the fruiting body of Russula japonica

Six new illudoid sesquiterpenes, russujaponols A-F (1-6), were isolated from the fruiting bodies of Russula japonica Hongo. Their structures were established primarily by 2D NMR experiments, and the structure of the main compound, russujaponol A (1), was confirmed by X-ray crystallographic analysis of its benzoate (1a). Russujaponol A (1) suppressed invasion of human fibrosarcoma (HT1080) cells into Matrigel in a concentration-dependent manner and caused 63% inhibition at 3.73 microM.     

Marinoquinolines A-F, pyrroloquinolines from Ohtaekwangia kribbensis (Bacteroidetes)

Marinoquinoline A (1) was isolated from the gliding bacterium Ohtaekwangia kribbensis together with the novel marinoquinolines B-F (2-6). Their structures were elucidated from NMR and HRESIMS data. The pyrroloquinolines showed weak antibacterial and antifungal activities and moderate cytotoxicity against four growing mammalian cell lines with IC(50) values ranging from 0.3 to 8.0 μg/mL. In a screening against tropical parasites marinoquinolines A-F (1-6) showed activity against Plasmodium falciparum K1 with IC(50) values between 1.7 and 15 μM.     

Asmarines A-F, novel cytotoxic compounds from the marine sponge Raspailia species

Three pairs of nitrogen-containing metabolites, asmarines A-F (1-6), were isolated from the Red Sea sponge Raspailia sp., collected in the Dahlak Archipelago, Eritrea. Although the first pair could fully be separated to give compounds 1 and 2, the other two pairs could only be enriched up to about 80% of one isomer. The structures of the new compounds were established by spectroscopic means. Besides the asmarines, methyl 3-oxo-cholan-24-oate (12) was also isolated. The absolute configuration of asmarine A (1) was determined on the basis of CD measurements of its unstable 18-oxo derivative (7) and mainly the Cotton effect of the dicarbonyl derivative (9) of chelodane (8). A O,N(7')-dimethyl derivative (10) and a second, unexpected, methylated product (11) were obtained from 2.     

Goniolactones A-F,six new styrylpyrone derivatives from the roots of Goniothalamus cheliensis

Six new styrylpyrone derivatives, goniolactones A-F (1-6), have been isolated from the roots of Goniothalamus cheliensis. The structures and stereochemistry of the new compounds were elucidated by interpretation of spectroscopic data and chemical methods. The relative configuration of goniolactone A (1) was determined by X-ray crystallography analysis, and the absolute configurations of goniolactones A (1) and B (2) were established by Mosher's method. Goniolactone B (2) exhibited significant cytotoxicity against A2780, HCT-8, and KB cells with IC(50) values of 7.40, 4.43, and 7.23 microM, respectively.     

Phaeosphaerins A-F, cytotoxic perylenequinones from an endolichenic fungus, Phaeosphaeria sp

Six novel phototoxins, phaeosphaerins A-F, together with six known perylenequinones were isolated from an endolichenic fungus Phaeosphaeria sp. Their structures were determined unequivocally on the basis of comprehensive analysis of MS and NMR data as well as electronic circular dichroism calculations. These toxins kill cancer cells in vitro with accumulation in lysosomes, and the killing effects were potently intensified in the presence of light.     

Rhabdastrellins A-F, isomalabaricane triterpenes from the marine sponge Rhabdastrella aff. distincta

Chemical examination of the marine sponge Rhabdastrella aff. distincta resulted in the isolation of six new isomalabaricane triterpenes, rhabdastrellins A-F (1-6), which were present as minor components, along with stellettins L and M. Their structures were elucidated on the basis of extensive spectroscopic data analyses and comparison with spectroscopic data of known analogues. The cytotoxicity of compounds 1-6 against a small panel of human tumor cell lines was also evaluated.     

Bitungolides A-F,new polyketides from the Indonesian sponge Theonella cf. swinhoei

Six new polyketides, bitungolides A-F (1-6), have been isolated from the Indonesian sponge Theonella cf. swinhoei and their structures elucidated by spectroscopic data and X-ray diffraction analysis. The bitungolides are a new class of Theonella metabolites that inhibit dual-specificity phosphatase VHR.