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From the leaves of Mallotus pallidus were isolated five phloroglucinol derivatives, namely pallidusol, dehydropallidusol, pallidol, mallopallidol and homomallopallidol. Their structures were determined by means of spectroscopic methods of analysis.
Three polyprenylated phloroglucinol derivatives, namely erectquione A, B, and C, were isolated from Hypericum erectum. Their structures were established using extensive spectral methods.
The isolation and identification of a new phloroglucinol derivative (2), a diterpenol (4), together with the known compounds flavesone (1) and sarothralen B (3), from the aerial parts of Hypericum japonicum are reported. Their structures were established by extensive spectral analysis and the structure of (3) has also been confirmed by a single crystal X-ray determination.
A new phloroglucinol derivative (1) and two known compounds (2 and 3) were isolated from the brown alga Eisenia bicyclis. These isolates exhibit inhibitory activity on glycation and alpha-amylase. Their structures were determined on the basis of spectroscopic data.
Two new and four known phloroglucinol derivatives were isolated from the dichloromethane extract of the Greek endemic plant Hypericum jovis. Their antioxidant activity was evaluated in vitro with the DPPH assay and in cell cultures using the DCFH-DA assay. All six compounds demonstrated significant antioxidant activity, while two of them possessed activity at a cellular level comparable to Trolox, protecting against ROS.
Three new phloroglucinols, garcinielliptones K (1), L (2), and M (3), and two new terpenoids, garcinielliptones N (4) and O (5), have been isolated from the seeds of Garcinia subelliptica. The structures of 1-5 including their relative configurations were elucidated by spectroscopic methods and supported by computer-generated molecular modeling. Compounds 2 and 3 showed potent inhibitory effects on the release of beta-glucuronidase, and on beta-glucuronidase and histamine, respectively, from peritoneal mast cells stimulated with p-methoxy-N-methylphenethylamine (compound 48/80) in a concentration-dependent manner. Compounds 2 and 3 showed potent effects on NO production in culture media of RAW 264.7 cells in response to lipopolysaccharide (LPS). Compound 2 also showed a potent effect on NO production in culture media of N9 cells in response to LPS/interferon-gamma (IFN-gamma).
Four acyl-phloroglucinol derivatives showing antiviral activity have been isolated from Kunzea sinclairii and Kunzea ericoides (Myrtaceae) from New Zealand. The structures of these compounds were deduced from analysis of spectral data. Two of these compounds, 1 and 2, are the isomers of isobutyryl methoxyresorcinol. The two new compounds, 3 and 4, were isolated as a mixture and determined to be 4-cyclohexene-1,3-dioxo-5-hydroxy-2,2,6,6-tetramethyl-4- (1-[2,6-dihydroxy-4- methoxy-3-(3-methyl-1-oxobutyl)phenyl]-3-methylbutyl) and its 2-methyl-1-oxopropyl analogue, respectively.
A new polyisoprenylated phloroglucinol derivative has been isolated from the twigs of Marila laxiflora and characterized on the basis of 1D and 2D NMR spectra. Laxifloranone (1) shows moderate inhibition of the cytopathic effects of in vitro HIV infection.
Bioactivity-guided fractionation of the petroleum ether extract of the aerial parts of Hypericum papuanum led to the isolation of five new tricyclic phloroglucinol derivatives. On the basis of extensive 1D and 2D NMR experiments as well as MS studies, their structures were elucidated as the C-3 epimers of 8-hydroxy-4,4, 7-trimethyl-9-(2-methylpropionyl)-3-(1-methylvinyl)-5beta -H-tricyclo[ 5.3.1.0(1,5)]undec-8-ene-10,11-dione (1,2); the C-3 epimers of 8-hydroxy-4,4, 7-trimethyl-9-(2-methylbutyryl)-3-(1-methylvinyl)-5beta-H-++ +tricyclo[5. 3.1.0(1,5)]undec-8-ene-10,11-dione (3, 4), and 8-hydroxy-4,4, 7-trimethyl-9-(2-methylpropionyl)-5beta-H-tricyclo[5.3 .1.0(1, 5)]undec-8-ene-10,11-dione (5), and their corresponding tautomers (1a, 2a, 3a, 4a, 5a). Compounds 1/1a-5/5a were named ialibinones A-E, respectively. Compounds 1/1a-4/4a showed antibacterial activity against Bacillus cereus, Staphylococcus epidermidis, and Micrococcus luteus.
[reaction: see text] A remarkable phenylboronic acid mediated triple condensation reaction of phloroglucinol (1,3,5-trihydroxybenzene) with a series of alpha,beta-unsaturated carbonyl compounds is reported. This experimentally simple reaction afforded novel C3-symmetric 2H-chromene derivatives. These derivatives represent structural analogues of the natural product xyloketal A, which has been reported to be a potent inhibitor of acetylcholine esterase.
[structure: see text] Three novel phloroglucinol derivatives of lysidicins A-C (1-3) have been isolated from the roots of Lysidice rhodostegia and structures were elucidated by comprehensive NMR and MS spectroscopic analysis. 1 and 2 possess spirocyclic benzodihydrofuran skeleton. Their relative stereochemistries were assigned by NOE or NOESY experiment. A plausible pathway for the biosynthesis of 1-3 from 4 and a ketose derivative was postulated.
Cytotoxic activity against the P388 cell line was seen in a crude extract of the New Zealand shrub Lophomyrtus bullata(Myrtaceae). Bioactivity-guided isolation led to a compound with NMR spectra complicated by the presence of two isomers. These crystallised together and an X-ray structure showed them to be stereoisomeric hybrids of triketone, phloroglucinol and bullatenone units. NMR measurements on the mixed isomers, as well as a cyclic ether produced from them by acid catalysed dehydration, were consistent with these structures. The natural products, named bullataketals A and B, have cytotoxic activity against the P388 cell line (IC(50) 1 microg ml(-1)), and antimicrobial activity against Bacillus subtilis.
A genomic lambda-library of Pelobacter acidigallici has been established. Proteolytic digestion of homogeneous pyrogallol-phloroglucinol transhydroxylase from the same microorganism afforded polypeptide fragments whose N-terminal sequences allowed the generation of oligonucleotide primers. Together with primers deduced from the known N-terminal sequences of the two intact subunits these were used in PCR experiments to obtain three amplificates. Screening the lambda-library with the three amplificates led eventually to clones containing the whole gene coding for the transhydroxylase. Sequencing the gene revealed two open reading frames coding for 875 and 275 amino acids which correspond to the alpha- and beta-subunits of THL, respectively. The two subunits are separated by a 48-bp noncoding region. Comparison of the sequence with those of other molybdopterin cofactor (MoCo)-enzymes places THL in the dimethylsulfoxide reductase family. Possible contact sites to the MoCo and to the iron-sulphur clusters were spotted. Using the expression vectors pQE 30 and pT 7-7 three constructs harbouring the THL gene were created. One of them carried a His6-tag at the N-terminus of the alpha-subunit, another at the C-terminus of the beta-subunit. Immunoblot analysis showed high expression of THL, but the inclusion bodies could not be refolded to active enzyme.
Two new cytotoxic alkylene phloroglucinols and one known compound were isolated through chromatographic separation from the methanolic extract of the dried fruits of Protorhus thouvenotii (Anacardiaceae). The compounds showed marginal in vitro cytotoxicity in the A2780 ovarian cancer cell line assay with an IC50 of 11 microg/mL.
Eleven compounds have been identified from the whole plants of Syzygium levinei (Myrtaceae) on the basis of spectroscopic analysis and chemical methods. Among these compounds, (Z)-1-(2,6-dihydroxy-4-methoxyphenyl)-oct-5-en-1-one (1), (3 E,7 Z)-1-(2,6-dihydroxy-4-methoxyphenyl)-deca-3,7-dien-1-one (2), and 1-(2-O-beta-D-glucopyranosyl-5,6-dihydroxy-4-methoxyphenyl)-octan-1-one (3) were characterized as new alkyl phloroglucinol derivatives, and 1-(2,6-dihydroxy-4-methoxyphenyl)-hexan-1-one (4) was identified as a new natural product. Compounds 1, 2, and 4 were found to inhibit the proliferation of leukemia K562 and HL-60 cells and also to induce the differentiation of K562 cells as determined by the appearance of matured morphology and the increase in the intracellular hemoglobin level.
Transgenic Pseudomonas fluorescens 5-2/4 with reinforced 2,4-diacetyl phloroglucinol (phl) production had shown increased biocontrol ability towards Pythium ultimum (Pu), but inferior root colonization ability compared to its wild type 5.014. Therefore, enhanced root colonization ability of the transgenic strain by repeated inoculation and reisolation on tomato plants was suggested. As a preparation for repeated inoculation and reisolation cycles, the construction of a negative control of the transgenic strain 5-2/4 by marking with lacZY and screening for a mutant possessing qualities comparable to 5-2/4 was performed. Morphologically, colonies of all of the 11 selected mutants were similar on MLXgal medium. The root colonization ability of two of the lacZY-marked strains (mutants 1 and 10) was comparable to the parental strain. These were also able to compete with the resident microflora of tomato seedlings to the same extent as the parental strain. Five mutants were excluded due to lower growth rates on Yeast Malt, King's B Medium (KB) and 0.1 Tryptic Soy Agar (mutant 4, 5 and 8), excessive growth and higher siderophore production on KB (mutant 10) and increased protease production (mutant 2). With respect to in vitro-antagonism of Pu, no differences could be found between the target strain and mutants 1, 3, 6, 7 and 9. Examination of sole carbon source utilization of these five lacZY-marked strains revealed a significantly higher utilization of alpha-D-lactose and lactulose compared to 5-2/4. However, significant differences could be found for 51% of the utilized carbon sources. Cluster analysis showed a high degree of similarity between 5-2/4 and mutant 1 both when analyzed with and without alpha-D-lactose. As mutant 1 also represented the colonization pattern most similar to the parental strain 5-2/4, it presents a presumptive subject for a negative control in the following inoculation and reisolation studies on tomato.
PURPOSE: Recent studies show the interesting efficacy of different drug combinations for the spontaneous expulsion of distal ureteral stones. We performed a randomized, prospective study to assess and compare the efficacy of 3 drugs as medical expulsive therapy for distal ureteral calculi. MATERIALS AND METHODS: A total of 210 symptomatic patients with distal ureteral calculi greater than 4 mm were randomly allocated to home treatment with phloroglucinol, tamsulosin or nifedipine (groups 1 to 3, respectively). Each group was given a corticosteroid drug and antibiotic prophylaxis with an injectable nonsteroidal anti-inflammatory drug was also used on demand. The primary end point was the expulsion rate and the secondary end points were expulsion time, analgesic use, need for hospitalization and endoscopic treatment as well as the number of workdays lost, quality of life and drug side effects RESULTS: The expulsion rate was significantly higher in group 2 (97.1%) than in groups 1 (64.3%, p <0.0001) or 3 (77.1%, p <0.0001). Group 2 significantly achieved stone passage in a shorter time than the other 2 groups and showed a significantly decreased number of hospitalizations as well as a better decrease in endoscopic procedures performed to remove the stone. The control of renal colic pain was significantly superior in group 2 compared with the other groups, resulting in fewer workdays lost. Group 3 showed lower analgesic use and decreased workdays lost compared with group 1. No difference in side effects was observed among the groups. CONCLUSIONS: Medical expulsive therapy should be considered for distal ureterolithiasis without complications before ureteroscopy or extracorporeal lithotripsy. The use of tamsulosin in this treatment regimen produced stone expulsion in almost all cases in a short time, allowing complete home patient treatment.
Under anaerobic conditions, resting cell suspensions of Coprococcus sp. Pe15 degraded 1 molecule of phloroglucinol to 2 molecules of acetic acid and 2 molecules of carbon dioxide. The organism metabolized the flavonoids rhamnetin and quercetin anaerobically in 20% rumen fluid medium but failed to grow under similar conditions at the expense of any of 39 other aromatic or flavonoid compounds tested.