Porric acid D from marine-derived fungus <Emphasis Type="Italic">Alternaria</Emphasis> sp. isolated from Bohai Sea

Porric acid D (1), a new dibenzofuran derivative, was isolated from the methanol extract of a marine-derived fungus, Alternaria sp., isolated from the Bohai Sea, together with a known compound, altenusin. Their structures were elucidated by spectroscopic analysis, including high-resolution mass spectroscopy, and 1 and 2-dimensional NMR techniques. Compounds 1 and 2 showed inhibitory activity against Staphyloccocus aureus with MIC 100 and 25 μg/mL, respectively.     

A novel bromophenol from marine red alga <Emphasis Type="Italic">Symphyocladia latiuscula</Emphasis>

2,3,6-Tribromo-4,5-dihydroxybenzyl ethyl ether (1), a new bromophenol, was isolated from the ethanol extract of marine red alga Symphyocladia latiuscula, with a known compound, 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2). Their structures were elucidated by spectroscopic analysis, including high-resolution mass spectroscopy, and 1 and 2-dimensional NMR techniques. Compounds 1 and 2 showed inhibitory activity against Staphyloccocus aureus with IC₅₀ 102 and 50 μg/mL, respectively.     

Investigation of the effect of berberines alkaloids in <Emphasis Type="Italic">Coptis chinensis</Emphasis> Franch on <Emphasis Type="Italic">Bacillus shigae</Emphasis> growthby microcalorimetry

The inhibitory effects of five berberines alkaloids (BAs) from rhizoma of Coptis chinensis Franch, a traditional Chinese medicinal (TCM) herb, on Bacillus shigae (B. shigae) growth were investigated by microcalorimetry. The power-time curves of B. shigae with and without BAs were acquired; meanwhile, the extent and duration of inhibitory effects on the metabolism were evaluated by growth rate constants (k1, k2), half inhibitory ratio (IC50), maximum heat output (Pmax), and peak time (tp). The values of k1 and k2 of B. shigae in the presence of the five BAs decreased with the increasing concentrations of BAs. Moreover, Pmax was reduced, and the value of tp increased with increasing concentrations of the five drugs. The inhibitory activity varied with different drugs. IC50 of the five BAs was respectively 75 μg/mL for berberine, 90 μg/mL for coptisine, 115 μg/mL for palmatine, 220 μg/mL for epiberberine, and 400 μg/mL for jatrorrhizine. The sequence of antimicrobial activity of the five BAs berberine ＞ coptisine ＞ palmatine ＞ epiberberine ＞ jatrorrhizine. The functional groups methylenedioxy at C2 and C3 on phenyl ring improve antimicrobial activity more strongly than methoxyl at C2 and C3 on phenyl ring. However, the effect of bacteriostasis is not significant with methylenedioxy or methoxyl at C9 and C10 on phenyl ring.     

Chemistry and cytotoxic activities of polyketides produced by the mangrove endophytic fungus <Emphasis Type="Italic">Phomopsis</Emphasis> SP. ZSU-H76

A new polyketide, 2-(7′-hydroxyoxooctyl)-3-hydroxy-5-methoxybenzeneacetic acid ethyl ester (1), together with three known compounds dothiorelone A (2), B (3), and C (4) were isolated from the mangrove endophytic fungus Phomopsis sp. ZSU-H76 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. Primary bioassays showed that 1 exhibited cytotoxicity against HEp-2 and HepG2 cells with IC₅₀ values of 25 and 30 μg/mL, respectively.     

Chemistry and antiproliferative activities of 3-methoxyflavones isolated from <Emphasis Type="Italic">Varthemia iphionoides</Emphasis>

A new isolated flavone, 4′-hydroxy-3,5,6,7-tetramethoxyflavone (6), together with seven known 3-O-methylated flavones isolated from the ethanol extract of the aerial parts of Varthemia iphionoides, were studied for DPPH free radical-scavenging and cytotoxic activities. Flavones 2, 3, 4, and 8 were the most active DPPH free-radical scavengers with inhibition percentage of 63.5, 42.9, 47.9, and 55.6, respectively, at a concentration of 100 μg/mL. Flavones 2 and 8 were the most active as inhibitor for human leukemia HL-60 cells; the IC₅₀ values after 48 h incubation were 20.5 and 23.9 μg/mL, respectively.     

A new naphtho-<Emphasis Type="Italic">γ</Emphasis>-pyrone from mangrove endophytic fungus ZSU-H26

A new naphtho-γ-pyrone, 5-hydroxy-6,8-dimethoxy-2-benzyl-4H-naphtho[2,3-b]-pyran-4-one (1), together with three known compounds 5,7-dihydroxy-2-methylbenzopyran-4-one (2), 3,5-dihydroxy-2,7dimethylbenzopyran-4-one (3) and cyclo(Tyr-Tyr) (4) were isolated from the mangrove endophytic fungus Phomopsis sp. ZSU-H26 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. Primary bioassays showed that 1 exhibited cytotoxicity against HEp-2 and HepG2 cells with IC₅₀ values of 10 and 8 μg/mL, respectively.     

Antifeedant and antifouling briaranes from the South China Sea gorgonian <Emphasis Type="Italic">Junceella juncea</Emphasis>

A new briarane diterpene, juncin ZII (1), along with three known briaranes (2–4), was isolated from the EtOH/CH₂Cl₂ extracts of the South China Sea gorgonian Junceella juncea. The structure of 1 was established by extensive spectroscopic analysis, including 1D and 2D NMR data. For compounds 1–4 and eight other briaranes (5–12) isolated from J. juncea previously, the antifeedant activity against second-instar larvae of Spodoptera litura and cytotoxicity against S. litura cells were investigated, and it was observed that they all exhibit medium antifeedant activity. Compounds 1, 8, 9, and 12 also showed potent antifouling activity against the larval settlement of barnacle Balanus amphitrite at nontoxic concentrations with EC₅₀ values of 0.004, 0.005, 2.82, and 0.447 μg/mL, respectively, while all compounds did not show obvious cytotoxicity against tumor cell lines K562, A549, Hela, and Hep-2. Their structure-activity relationship was discussed. Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 44–47, January–February, 2009.     

Structure–antibacterial relationship of nigericin derivatives

Two new polyether antibiotics 3, 5 together with three known ones 1, 2, 4 were isolated from Streptomyces hygroscopicus XM201. Based on the unambiguous NMR data assignments, their structures were determined to be 30-acetyl nigericin (1), 1-O-methyl-30-acetyl nigericin (2), 1,29-O-dimethyl-30-acetyl nigericin (3), nigericin (4), and 29-O-methyl abierixin (5), respectively. The antibacterial activities of the nigericin derivatives 1–4 were studied. Compounds 1 and 4 showed strong activities against Staphylococcus aureus ATCC25923 and Bacillus cereus 1126 with MIC of 0.25 μg/mL and 0.125 μg/mL, respectively. No inhibitory activities were observed against Escherichia coli CMCC44103 at a concentration of 25 μg/mL. Only 1 and 4 showed distinguished effects on the protoplast regeneration clones of B. cereus 1126 and E. coli CMCC44103 at a concentration of 1 μg/mL. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 285–288, May–June, 2009.     

GC-FID optimization and validation for determination of 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine and methamphetamine in ecstasy tablets

A methodology for the determination of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA) and methamphetamine (MA) in seized tablets using gas chromatography with a flame ionization detector (GC-FID) is described. The chromatographic conditions, i.e. gas flow rates and temperatures for the column, injector and detector were optimized. The optimum chromatographic conditions were as follows: a CP-SIL 24 CB WCOT fused silica capillary column (30 m × 0.32 mm I.D., 0.25 μm film thickness), N₂ carrier gas flowing at 2.6 mL/min, injector temperature at 290°C and detector temperature at 300°C. The oven temperature was ramped from 80°C at a rate of 20°C/min to final temperature of 270°C (1 min). All analytes were well separated within 7 min with an analysis time of 10.5 min. Calibration curves were linear over the concentration ranges of 3.125–200 μg/mL for MDMA and 6.25–200 μg/mL for MDA and MA (r > 0.990). The intra- and inter-day precisions for determining all analytes were 2.32–10.38% RSD and 1.15–9.77% RSD, respectively. The intra- and inter-day accuracies ranged from −19.79 to +17.51% DEV and −6.84 to +5.2% DEV, respectively. The lower limits of quantification (LLOQs) were 3.125 μg/mL for MDMA and 6.25 μg/mL for MDA and MA. All analytes were stable at room temperature during 24 h but significant loss occurred after 2-month storage at −20°C. The method was shown to be useful for determining the purity of MDMA in seized tablets.     

Determination of imidacloprid in paddy water and soil by liquid chromatography electrospray ionization-tandem mass spectrometry

A method for the determination of imidacloprid in paddy water and soil was developed using liquid chromatography electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS). Separation of imidacloprid was carried out on a Shimadzu C18 column (150 mm × 4.6 mm, 4.6 μm) with an acetonitrile-water (50: 50, v/v) mobile phase containing 0.1% of acetic acid. The flow rate was 0.3 mL/min in isocratic mode. The product ion at 209 m/z was selected for quantification in multiple-reaction monitoring scan mode. Imidacloprid residues in soil were extracted by a solid-liquid extraction method with acetonitrile. Water samples were filtered and directly injected for analysis without extraction. Detection limits of 0.5 μg/kg and 0.3 μg/L were achieved for soil and water samples, respectively. The method had recoveries of 90 ± 2% (n = 4) for soil samples and 100 ± 2% (n = 4) for water samples. A linear relationship was observed throughout the investigated range of concentrations (1–200 μg/L), with the correlation coefficients ranging from 0.999 to 1.000.     

Extraction–thermal lens quantification of cobalt with Nitroso-R-Salt in two-phase aqueous systems with water-soluble polymer polyethylene glycol

A novel method is proposed for the extraction-thermal lens quantification of cobalt with Nitroso-R-Salt based on the distribution of the colored complex in a two-phase aqueous system on the basis of poly-ethylene glycol (PEG) and an ammonium sulfate solution followed by its thermal lens detection in the extract. The limit of detection is 0.3 μM (20 ng/mL); the lower limit of the analytical range is 0.7 μM (40 ng/mL); the relative standard deviation for the concentrations 1–50 μM makes 1–3% (n = 6, P = 0.95). In the determination of cobalt by spectrophotometry under the same conditions, the detection limit is 10 μM (0.6 μg/mL) and the lower limit of the analytical range is 40 μM (2.5 μg/mL). The precision of thermal lens measurements in PEG solutions is higher in comparison to that in aqueous ones because of the weaker interference of convection in aqueous solutions of PEG.     

Development of spectrofluorimetric methods for the determination of levosulpiride in pharmaceutical formulation

Simple, accurate, rapid, and sensitive spectrofluorimetric methods for the determination of levosulpiride in pharmaceutical formulation were developed utilizing its fluorescence reaction with Fe³⁺ (method A) and Al³⁺ (method B). The calibration curves were found to be linear in the concentration range 0.239–3.44 μg/mL and 0.310–2.730 μg/mL with limit of detection 0.005 μg/mL and 0.0032 μg/mL, respectively, for method A and method B. The reaction conditions were studied and optimized. In addition, the complexation of Mg²⁺ and Ca²⁺ was also studied. In all cases, an enhancement in fluorescence emission of levosulpiride upon formation of complex with metal ions was observed. A 2: 1 (drug: metal) stoichiometry for all the complexes was established. Benesi-Hildebrand method was applied for calculation of association constant at 25 and 35°C. The thermodynamic parameters obtained in this study revealed that the interaction process was spontaneous and mainly ΔS-driven.     

Antioxidant flavonoids from <Emphasis Type="Italic">Tamus communis</Emphasis> ssp. <Emphasis Type="Italic">cretica</Emphasis>

A new flavonoid, kaempferol-3,4′-di-O-α-L-rhamnopyranoside (1), and three known flavonoids (2–4) were isolated from the aerial parts of T. communis L. The structure of the new compound was elucidated on the basis of spectroscopic data. Compounds 1 and 2 showed significant antioxidant activity (IC₅₀ 187.151 ± 0.821 μM, and 92.079±0.513 μM, respectively), whereas compounds 3 and 4 showed moderate activity in DPPH free radical scavenging assays. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 295–297, May–June, 2009.     

A new xanthone derivative from mangrove endophytic fungus No. ZSU-H16

A new xanthone derivative, 3,5,8-trihydroxy-2,2-dimethyl-3,4,4-trihydro-2H,6H-pyrano[3,2-b]-xanthen-6one (1), together with three known compounds, 5,8-dihydroxy-2,2-dimethyl-2H,6H-pyrano[3,2-b]xanthen6-one (2), cyclo-(N-O-methyl-L-Trp-L-Ile-D-Pip-L-2-amino-8-oxo-decanoyl) (3), and cyclo-(Phe-Tyr) (4), was isolated from the mangrove endophytic fungus No. ZSU-H16 obtained from the South China Sea coast. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. Compound 1 exhibited cytotoxicity against KB and KB_V 200 cells with IC₅₀ values greater than 50 μg/mL, respectively.     

A new acylated triterpene with antimicrobial activity from the leaves of <Emphasis Type="Italic">Rauvolfia vomitoria</Emphasis>

A new acylated tritrepene, 3β-hexadecanoyloxy-lup-20(29)-en-21-ol (1), along with seven known compounds, lupeol (2), betulinic acid (3), ursonic acid (4), -sitosterol (5), β-stigmasterol (6), 3-O-β-D-glucopyranosyl-β-stigmasterol (7), and palmitic acid (8), were isolated from the leaves of Rauvolfia vomitoria (Apocynaceae). Their structures were established on the basis of spectroscopic analysis and chemical evidence. The new acylated triterpene exhibited interesting antimicrobial activity against Candida albicans (a yeast) with the MIC value 64 μg/mL.     

Antitumor sesquiterpene polyol esters from <Emphasis Type="Italic">Celastrus angulatus</Emphasis>

Two new antitumor sesquiterpene polyol esters with the β-dihydroagarofuran skeleton, 1 and 2, and three known compounds 3–5 were isolated from the high-polar MeOH extracts of the root bark of Celastrus angulatus. Their chemical structures were elucidated mainly by analyses of MS and NMR spectral data. Preliminary antitumor and insecticidal activities of these compounds were evaluated. Compounds 1 and 2 exhibited moderate antitumor activity against human breast cancer cell line (Bcap-37); the IC50 were 54.08 and 61.35 μM, respectively, and all the tested compounds were shown to possess minimal or no inhibitory activities against human colon (HT-29) and lung (NCI-H460) cancer cell lines. In addition, compounds 1–5 displayed mild insecticidal activities against the 4th instar larvae Mythimna separate, the KD50 were 610.5, 308.8, 917.8, 510.6 and 1120.5, respectively.     

A new stilbene glycoside from the <Emphasis Type="Italic">n</Emphasis>-butanol fraction of <Emphasis Type="Italic">Veratrum dahuricum</Emphasis>

A new stilbene glycoside, 5-methylresveratrol-3,4′-O-β-D-diglucopyranoside (1), was isolated from the n-butanol fraction of the rhizomes of Veratrum dahuricum, together with five known stilbenoids: resveratrol-3-O-β-D-glycoside (2), 4′-methylresveratrol-3-O-β-D-glycoside (3), oxyresveratrol-4′-O-β-D-glycoside (4), oxyresveratrol-3-O-β-D-glycoside (5), and oxyresveratrol-3,4′-O-β-D-diglycoside (6), and found for the first time in the investigated plant. The structures of six isolates were identified on the basis of 1D and 2D NMR data. Compounds 1–6 showed platelet aggregation inhibition, and compound 1 had an IC₅₀ value of 383.6 μM against platelet aggregation induced by AA. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 279–282, May–June, 2009.     

Airlanggins A-B,two new isoprenylated benzofuran-3-ones from the stem bark of Calophyllum soulattri

Two new isoprenylated benzofuran 3-ones, airlanggin A (1) and B (2) along with two known xanthones, ananixanthone (3) and trapezifolixanthone (4) were isolated from the stem bark of Calophyllum soulattri. Structures of all the compounds were elucidated using extensive spectroscopic methods, including UV, IR, HRESIMS, 1D and 2D NMR. Compounds 1–4 were evaluated for their cytotoxicity against P-388 cells, showing that compound 3 was the most active with IC₅₀ 0.68 μg/mL and compound 1 showed moderate activity with IC₅₀ 5.80 μg/mL.     

Two novel phenolic compounds from <Emphasis Type="Italic">Stenoloma chusanum</Emphasis> and their antifungal activity

Two new phenolic compounds, 4-O-β-D-(6-O-gentisoylglucopyranosyl) vanillic acid (1), 2-O-β-D-(6-O-gentisoylglucopyranosyl) gentisic acid (2), together with three known compounds, vanillic acid (3), syringic acid (4), and gentisic acid (5), were isolated from the whole part of Stenoloma chusanum (L.) Ching. Structures of the two new compounds 1, 2 were elucidated on the basis of spectroscopic methods, including twodimensional NMR techniques and HR ESI-MS analysis. The compounds′ activities against Candida albicans, Cryptococcus neoformans, Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, Epidermophyton floccosum, and Aspergillus niger were determined, and the minimal inhibitory concentrations (MIC) were 25–100 μg/mL. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 161–164, March–April, 2009.     

Sequential injection technique for determination of phenoxybenzamine hydrochloride and metoclopramide in pharmaceutical formulations

A sequential injection analysis (SIA) system is described for the determination of phenoxybenzamine hydrochloride and metoclopramide using spectrophotometer as detector. The method is based on the detection of an unstable red intermediate compound resulting from the reaction of phenoxybenzamine hydrochloride or metoclopramide with the diazotizating product of p-phenylenediamine with sodium nitrite in hydrochloric acid medium. The sampling frequency is 69 h⁻¹ and 75 h⁻¹ for phenoxybenzamine hydrochloride and metoclopramide, respectively. The linear range is 10–400 μg/mL for phenoxybenzamine hydrochloride with a detection limit of 0.081 μg/mL and 20–250 μg/mL for metoclopramide with a detection limit of 0.034 μg/mL. The RSD is 1.01 and 0.45% for phenoxybenzamine hydrochloride and metoclopramide, respectively. The proposed methods were used to determine phenoxybenzamine hydrochloride and metoclopramide in pharmaceuticals. The results are compared with those obtained by pharmacopoeia method. The article is published in the original.