Zooxanthellamide B, a novel large polyhydroxy metabolite from a marine dinoflagellate of Symbiodinium sp

Zooxanthellamide B, C(128)H(220)N(2)O(53)S(2), a polyhydroxy secondary metabolite, was isolated from a cultured marine dinoflagellate of the genus Symbiodinium. A detailed 2D NMR analysis revealed the chemical structure as a delta-lactone analogue of zooxanthellamide A, which had previously been isolated from the same dinoflagellate by us. The relative configuration of the delta-lactone moiety was determined by NOE experiments and a coupling constant analysis, and that of other ring systems was found to be the same as zooxanthellamide A by the chemical correlation between zooxanthellamides A and B.     

Helianthol a,a sesquiterpene alcohol from Helianthus tuberosus

A new sesquiterpene alcohol, helianthol A, was isolated from the aerial parts of Helianthus tuberosus. The structure of this compound has been established as (+)-2-methyl-6-[4-methyl-3′-cyclohexen-1′-(R)-yl]-3,6-heptadien-2-ol by chemical and spectroscopic methods.     

Lysianadioic acid, a carboxypeptidase B inhibitor from Lysiana subfalcata

A new natural product, lysianadioic acid, was isolated from the plant Lysiana subfalcata as a carboxypeptidase B (CPB) inhibitor. It is a potent inhibitor of CPB with an IC(50) of 0.36 microM. This is the first known example of a small molecule CPB inhibitor isolated from plant origin. Its structure was determined by NMR spectroscopy.     

Dorycnioside, a new phenylbutanone glucoside from Dorycnium pentaphyllum subsp. herbaceum

A new phenylbutanone glucoside, dorycnioside, was isolated from the methanol extract of the aerial parts of Dorycnium pentaphyllum subsp. herbaceum Vill. (Rouy) and identified as 4-(4'-O-beta-D-glucopyranosyl-3',5'-dimethoxyphenyl)-2-butanone (1). In addition, two known phenylbutanone glucosides, five flavonoids, one cyanogenic glucoside, one cyclitol and one hydroquinone glucoside were also isolated and identified. The major constituent of the methanol extract was found to be myricitrin. The structure of 1 was elucidated on the basis of its spectroscopic data. It is the first time that derivatives of phenylbutanone are isolated from the Leguminosae family.     

Trechonolide A,a new withanolide type from Trechonaetes laciniata

The structure of a new withanolide type isolated from Trechonaetes laciniata, having a hemiacetal ring system and a 5-member ring lactone has been elucidated by X-ray analysis as (23R)-5β,6β-epoxy-12β,17β-dihydroxy-1-oxo-12,22-hemiacetal-ergosta-2,24-dien-23,26-olide (trechonolide A). A second compound (trechonolide B) having at C-12 a β-methoxy group, has also been isolated and assumed to be an artifact since, by heating trechonolide A in methanol with a trace of acid, the methoxy derivative was produced.     

1,2-Dehydrolactarolide A, a new plant growth regulatory lactarane sesquiterpene from Lactarius vellereus

A new lactarane sesquiterpene, 1,2-dehydrolactarolide A (1), together with lactarorufin A (2), 3-O-ethyllactarolide A (3) and 3-O-ethyllactarolide B (4), was isolated from a mushroom of the Russulaceae family, Lactarius vellereus. Additionally, two lactarane sesquiterpenes, lactarorufin A (2) and lactarolide A (5) were isolated from L. subpiperatus. 1,2-Dehydrolactarolide A (1) showed promotional activity (152% at 3.6 x 10(1) microM) toward radicle elongation in lettuce seedlings.     

Brandioside, a phenylpropanoid glycoside from Brandisia hancei.

A new phenylpropanoid glycoside, brandioside, was isolated from Brandisia hancei. Its structure, [beta-(3',4'-dihydroxylphenyl)-ethyl]-(2-O-acetyl)-(3,6-O-di-alpha -L-rhamnopyranosyl)-(4-O-caffeoyl)-beta-D-glucopyranoside, was established by chemical and spectroscopic methods.     

毛萼香茶菜中的一个新二萜

从毛萼香茶菜中分得8个二萜,3-乙酰毛萼结晶S、毛萼结晶甲、毛萼结晶乙、毛萼结晶丙、毛萼结晶丁、trichrokaurin、edonicin和eriocalyxin B。其中3-乙酰毛萼结晶S为新的对映-贝壳杉烷型二萜。由波谱法确定其结构。     

Vibriobactin, a siderophore from Vibrio cholerae

A novel siderophore (microbial iron transport compound) has been isolated from low iron cultures of Vibrio cholerae. Belonging to the catecholamide family of chelators, it has been shown to contain three residues of 2,3-dihydroxybenzoic acid and two residues of threonine. Both threonine moieties are present in the form of oxazoline rings. Furthermore, the polyamine backbone of the molecule was proved to be not spermidine, but the rare N-(3-aminopropyl)-1,3-diaminopropane, norspermidine. The structure of the new siderophore has been determined to be N-[3-(2,3-dihydroxybenzamido)propyl]-1, 3-bis[2,3-dihydroxyphenyl)-trans-5-methyl-2-oxazoline-4-carboxamido]prop ane. The compound has been given the trivial name vibriobactin. Mutants defective in the synthesis and utilization of vibriobactin were isolated. In an iron-limited environment V. cholerae was found to respond more strongly to vibriobactin, agrobactin, and ferrichrome than to enterobactin.     

Isoangoroside C, a phenylpropanoid glycoside from Scrophularia scorodonia roots

A new phenylpropanoid glycoside isoangoroside C was isolated from the roots of Scrophularia scorodonia. Its structure was determined on the basis of spectral data as: 3-hydroxy-4-methoxy-beta-phenylethoxy-O-alpha-L-arabinopyranosy l-(1-->6)alpha L-rhamnopyranosyl-(1-->3)-4-O-Z-feruloyl-beta-D-glucopyranoside. Additionally, one known phenylpropanoid, angoroside C, and five known iridoid glycosides, harpagoside, bartsioside, 8-O-acetyl-harpagide, aucuboside and harpagide were isolated and identified.     

Cloning, sequencing and expression of a novel glutamate decarboxylase gene from a newly isolated lactic acid bacterium, Lactobacillus brevis OPK-3

Lactobacillus brevis OPK-3, having 84.292 mg/L/h of gamma-aminobutyric acid (GABA) productivity, was isolated from Kimchi, a traditional fermented food in Korea. A core fragment of glutamate decarboxylase (GAD) DNA was isolated from the L. brevis OPK-3, using primers based on two highly conserved regions of GAD. A full-length GAD (LbGAD) clone was subsequently isolated through rapid amplification of cDNA ends (RACE) PCR. Nucleotide sequence analysis revealed that the open reading frame (ORF) consisted of 1401 bases and encoded a protein of 467 amino acid residues with a calculated molecular weight of 53.4 kDa and a pI of 5.65. The amino acid sequence deduced from LbGAD ORF showed 83%, 71%, and 60% identity to the Lactobacillus plantarum GAD, Lactococcus lactis GAD, and Listeria monocytogenes GAD sequences, respectively. The LbGAD gene was expressed in Escherichia coli strain UT481, and the extract of transformed E. coli UT481 contained an induced 53.4 kDa protein and had significantly enhanced GAD activity.     

Pseudodeflectusin, a novel isochroman derivative from Aspergillus pseudodeflectus a parasite of the sea weed, Sargassum fusiform, as a selective human cancer cytotoxin

A new isochroman derivative named pseudodeflectusin was isolated from a culture broth of Aspergillus pseudodeflectus. The structure was determined by spectroscopic means as 9-hydroxy-7-methyl-2-(methylethylidine)-furano[3,2-H]isochroman-3-one. This compound exhibited cytotoxicity for several human cancer cell lines from the stomach (NUGC-3), cervix (HeLa-S3), and peripheral blood (HL-60), but did not affect those from the lung (A549) or colon (DLD-1). The LD50 value of this compound for HL-60 cells was 39 microM.     

Deoxycollybolidol,a sesquiterpene from collybia peronata

A crystalline compound, deoxycollybolidol, was isolated from the chloroform-methanol extracts of Collybia peronata. On the basis of elemental analysis and spectral data, the structure 3β-(3-furyl)-3,4,4aα,8β,9,9aα-hexahydro-5-β-methyl is proposed     

Soraphinol C, a new free-radical scavenger from Sorangium cellulosum

A new compound named soraphinol C (1) was isolated from myxobacteria Sorangium cellulosum KM1001 a soil isolate, together with a structurally related known compound, 4-hydroxysattabacin (2). These compounds were isolated by silica gel column chromatography and recycling preparative HPLC, consecutively. The structures of the compounds were determined on the basis of combined spectroscopic analyses. Compounds 1 and 2 exhibited antioxidant activity as a radical scavenger in the experiment using a hydrophilic free-radical initiator, 2,2'-azobis(2-amidinopropane)dihydrochloride with ORAC values of 0.956 and 0.617, respectively.     

Anasterocerebroside A,a new glucosylceramide from the Patagonian starfish Anasterias minuta

Eight glucosylceramides (1-8) were isolated from the water-insoluble lipid fraction of a methylene chloride/methanol/water extract of the Patagonian starfish Anasterias minuta. One of the constituents was identified as a new glucosylceramide, anasterocerebroside A (1), while the known glucosylceramide 7 was isolated and characterized for the first time as a pure compound. The structures of 1 and 7 were established by spectroscopic and chemical methods.     

Production, purification, and characterization of antifungal metabolite from Pseudomonas aeruginosa SD12, a new strain obtained from tannery waste polluted soil

A new strain, SD12, was isolated from tannery waste polluted soil and identified as Pseudomonas aeruginosa on the basis of phenotypic traits and by comparison of 16S rRNA sequences. This bacterium exhibited broad-spectrum antagonistic activity against phytopathogenic fungi. The strain produced phosphatases, cellulases, proteases, pectinases, and HCN and also retained its ability to produce hydroxamate-type siderophore. A bioactive metabolite was isolated from P. aeruginosa SD12 and was characterized as 1-hydroxyphenazine ((1-OH-PHZ) by nuclear magnetic resonance (NMR) spectral analysis. The strain was used as a biocontrol agent against root rot and wilt disease of pyrethrum caused by Rhizoctonia solani. The stain is also reported to increase the growth and biomass of Plantago ovata. The purified compound, 1-hydroxyphenazine, also showed broad-spectrum antagonistic activity towards a range of phytopathogenic fungi, which is the first report of its kind.     

Quantification of siderophore and hemolysin from Stachybotrys chartarum strains, including a strain isolated from the lung of a child with pulmonary hemorrhage and hemosiderosis

A strain of Stachybotrys chartarum was recently isolated from the lung of a pulmonary hemorrhage and hemosiderosis (PH) patient in Texas (designated the Houston strain). This is the first time that S. chartarum has been isolated from the lung of a PH patient. In this study, the Houston strain and 10 strains of S. chartarum isolated from case (n = 5) or control (n = 5) homes in Cleveland were analyzed for hemolytic activity, siderophore production, and relatedness as measured by random amplified polymorphic DNA analysis.     

Cyclonatsudamine A, a new vasodilator cyclic peptide from Citrus natsudaidai

A new cyclic heptapeptide, cyclonatsudamine A (1), cyclo (-Gly-Tyr-Leu-Leu-Pro-Pro-Ser-), has been isolated from the peels of Citrus natsudaidai and the structure was elucidated by 2D NMR analysis and chemical degradation. Cyclonatsudamine A (1) relaxed norepinephrine-induced contractions of rat aorta, which may be mediated through the increased release of NO from endothelial cells.     

Agrobactin, a siderophore from Agrobacterium tumefaciens.

A siderophore (microbial iron transport compound) was isolated from low iron cultures of Agrobacterium tumefaciens B6. The substance was characterized as a threonyl peptide of spermidine acylated with 3 residues of 2,3-dihydroxybenzoic acid, the carbonyl group of 1 residue of the latter participating in an oxazoline ring with the beta-hydroxyl of the threonine moiety. The compound, N-[3-(2,3-dihydroxybenzamido)propyl]-N-[4-(2,3-dihydroxybenzamido)butyl]-2-(2,3-dihydroxyphenyl)-trans-5-methyl-oxazoline-4-carboxamide, was given the trivial name agrobactin. Exposure to acid opened the oxazoline ring to afford agrobactin A. Ferric agrobactin A and agrobactin A itself, but not agrobactin or its ferric complex, had some capacity to feed iron to enterobactin-deficient strains of Escherichia coli and Salmonella typhimurium. Agrobactin was produced by A. tumefaciens in response to iron deficiency and was able to reverse the iron starvation in this organism precipitated by the presence of a ferric complexing agent not utilized by the cells.     

Isosojagol,a coumestan from Phaseolus coccineus

A novel coumestan isolated from Phaseolus coccineus has been characterized as 3,9-dihydroxy-10-(γ,γ-dimethylallyl)-coumestan and named isosojagol.