17T223A, a new spiroximicin family compound from Streptomyces sp.

In this study, we successfully isolated two compounds, 17T223A (1, C22 H22 O10 ) and 17T223B (2, C22 H20 O9 ), from a culture of Streptomyces sp. 17T223. Spectroscopic analyses revealed that these two compounds belong to the spiroximicin family. The chemical structure of 2 was consistent with that of the established antibiotic spiroximicin, whereas 1 was previously unknown. Furthermore, 1 exhibited moderate radical -scavenging activity, with an ED 50 of 1000 µM, whereas 2 showed no radical -scavenging activity, even at an ED50 of 2000 µM. Significant antimicrobial activity was exhibited by 2 whereas 1 exhibited no antimicrobial activity, suggesting that the epoxide portion of 2 influences its antimicrobial activity.

Absorption and Metabolism of Luteolin in Rats and Humans in Relation to in Vitro Anti-inflammatory Effects.

Luteolin is a flavonoid present in plants in the form of aglycone or glucosides. In this study, luteolin glucosides (i.e., luteolin-7- O-ß-d-glucoside, luteolin-7- O-[2-(ß-d-apiosyl)-ß-d-glucoside], and luteolin-7- O-[2-(ß-d-apiosyl)-6-malonyl-ß-d-glucoside]) prepared from green pepper leaves as well as luteolin aglycone were orally administered to rats. Regardless of the administered luteolin form, luteolin glucuronides were mainly detected from plasma and organs. Subsequently, luteolin aglycone, the most absorbed form of luteolin in rats, was orally administered to humans. As a result, luteolin-3'- O-sulfate was mainly identified from plasma, suggesting that not only luteolin form but also animal species affect the absorption and metabolism of luteolin. When LPS-treated RAW264.7 cells were treated with luteolin glucuronides and luteolin sulfate (the characteristic metabolites identified from rats and humans, respectively), the different luteolin conjugates were metabolized in different ways, suggesting that such difference in metabolism results in their difference in anti-inflammatory effects.

12T061A and 12T061C, two new julichrome family compounds, as radical scavengers from Streptomyces sp.

We identified two new radical scavengers, 12T061A (1, C19H20O7) and 12T061C (2, C20H22O7), from a culture of the Streptomyces sp. Spectroscopic analysis indicated that these compounds are new julichrome family compounds. Compounds 1 and 2 showed radical-scavenging activity with an ED50 of 370 µM and 18 µM, respectively. Moreover, 1 showed tumor cell growth suppressive activity in HepG2 cells, (IC50: 3.6 µM); however, no suppressive activity was shown in 2 (IC50: > 100 µM).

Effect of heat processing on antibody reactivity to allergen variants and fragments of black tiger prawn: A comprehensive allergenomic approach.

SCOPE: Prawn allergy is one of the leading causes of IgE-mediated hypersensitivity to food. Alterations of IgE-antibody reactivity to prawn allergens due to thermal processing are not fully understood. The aim of this study was to analyze the impact of heating on prawn allergens using a comprehensive allergenomic approach. METHODS AND RESULTS: Proteins from raw and heat-processed black tiger prawn (Penaeus monodon) extracts as well as recombinant tropomyosin (rPen m1) were analyzed by SDS-PAGE and immunoblotting using sera from 16 shellfish allergic patients. IgE antibody binding proteins were identified by advanced mass spectroscopy, characterized by molecular structure analysis and their IgE reactivity compared among the prepared black tiger prawn extracts. Heat processing enhanced the overall patient IgE binding to prawn extracts and increased recognition of a number of allergen variants and fragments of prawn allergens. Allergens identified were tropomyosin, myosin light chain, sarcoplasmic calcium binding protein, and putative novel allergens including triose phosphate isomerase, aldolase, and titin. CONCLUSION: Seven allergenic proteins are present in prawns, which are mostly heat-stable and form dimers or oligomers. Thermal treatment enhanced antibody reactivity to prawn allergens as well as fragments and should be considered in the diagnosis of prawn allergy and detection of crustacean allergens in processed food.

Impact of heat processing on the detection of the major shellfish allergen tropomyosin in crustaceans and molluscs using specific monoclonal antibodies.

The major heat-stable shellfish allergen, tropomyosin, demonstrates immunological cross-reactivity, making specific differentiation of crustaceans and molluscs for food labelling very difficult. The aim of this study was to evaluate the application of allergen-specific monoclonal antibodies in differential detection of shellfish-derived tropomyosin in 11 crustacean and 7 mollusc species, and to study the impact of heating on its detection. Cross-reactive tropomyosin was detected in all crustacean species, with partial detection in molluscs: mussels, scallops and snails but none in oyster, octopus and squid. Furthermore, we have demonstrated that heating of shellfish has a profound effect on tropomyosin detection. This was evident by the enhanced recognition of multiple tropomyosin variants in the analysed shellfish species. Specific monoclonal antibodies, targetting the N-terminal region of tropomyosin, must therefore be developed to differentiate tropomyosins in crustaceans and molluscs. This can help in correct food labelling practices and thus protection of consumers.

6'-Hydroxyoxosorbicillinol, a new lipoxygenase inhibitor and PGD2/LTB4 release suppressor from Penicillium sp.

A new lipoxygenase inhibitor, 6'-hydroxyoxosorbicillinol (1, C(14) H(16)O(6)), was identified from a culture of Penicillium sp. A known compound, oxosorbicillinol (2, C(14)H(16)O(5)), was also isolated. Compound 1 showed an approximately 10 times greater inhibitory effect on soybean lipoxygenase (IC(50), 16 µM) than 2 (IC(50), 150 µM), and also showed prostaglandin D(2) (PGD(2)) and leucotriene B(4) (LTB(4)) release suppression activity (IC(50), 10 µM for PGD(2) and 100 µM for LTB(4)).

10T024A, a new phenazine derivative, as a radical scavenger and a prostaglandin, leukotriene release suppressor.

We identified a new radical scavenger, 10T024A (C(15)H(12)N(2)O(4)), from a culture of the Streptomyces sp. Spectroscopic elucidation indicated that this compound is a new phenazine derivative. 10T024A showed radical-scavenging activity with an ED(50) of 125 µM. Moreover, it showed prostaglandin D(2) (PGD(2)) and leukotriene B(4) (LTB(4)) release suppressive activity in rat basophilic leukemia (RBL-2H3) cells, at IC(50): 8 µM and 10 µM respectively.

Ansaetherone, a new radical scavenger from Streptomyces sp.

We identified a new radical scavenger, ansaetherone (C26 H33 NO7), from a culture of the Streptomyces sp. USF-4727 strain. In our previous study, it was shown that this strain produced four lipoxygenase inhibitors, tetrapetalones A, B, C and D. The chemical structure of ansaetherone was elucidated by the spectroscopic method, indicating that this compound was constructed with an aglycon and a sugar moiety. This chemical structure suggested that ansaetherone was related to the tetrapetalones. This finding provided information regarding tetrapetalone biosynthesis. Ansaetherone showed radical scavenging activity with an ED50 value of 300 microM in our assay.

Biosynthesis of tetrapetalones.

The biosynthesis of tetrapetalones (tetrapetalones A, B, C, and D) in Streptomyces sp. USF-4727 was studied by feeding experiments with [1-13C] sodium propanoate, [1-13C] sodium butanoate, [carbonyl-13C] 3-amino-5-hydroxybenzoic acid (AHBA) hydrochloride, and [1-13C] glucose, followed by analysis of the 13C-NMR spectra. These feeding experiments revealed that the four tetrapetalones were polyketide compounds constructed from propanoate, butanoate, AHBA, and glucose. The tetrapetalone biosynthetic pathway was also suggested in this study. In this pathway, tetrapetalone A (1) is synthesized by polyketide synthase (PKS) using AHBA as a starter unit, then the side chain of 1 is subjected to acetoxylation to produce tetrapetalone B (2). Additionally, 1 is oxidized and transformed into tetrapetalone C (3). In a similar way, 2 is converted to tetrapetalone D (4). Therefore, the biosynthetic relationship of the four tetrapetalones was indicated.

Novel lipoxygenase inhibitors, tetrapetalone B, C, and D from Streptomyces sp.

Three novel lipoxygenase inhibitors, tetrapetalone B (2, C(28)H(35)NO(9)), C (3, C(26)H(34)NO(8)), and D (4, C(28)H(36)NO(10)), were isolated from a culture broth of Streptomyces sp. USF-4727 that produced a lipoxygenase inhibitor tetrapetalone A (1) simultaneously. Each chemical structure was revealed by spectroscopic evidence, this suggests that these three compounds are structurally related to 1. They had a tetracyclic skeleton and a beta-D-rhodinosyl moiety. Tetrapetalone B, C, and D inhibited soybean lipoxygenase with IC(50): 320, 360, and 340 microM respectively.

Tetrapetalone A, a novel lipoxygenase inhibitor from Streptomyces sp.

A simple new assay was designed for lipoxygenase inhibitors. This assay was used to find the novel lipoxygenase inhibitor, tetrapetalone A (1). Tetrapetalone A (1), C26H33NO7, was isolated from Streptomyces sp. USF-4727 strain. Its planar structure was determined by spectroscopic evidence and by methylating with diazomethane to show the presence of a novel tetracyclic skeleton and a beta-D-rhodinosyl moiety. The stereochemistry of 1 was investigated by the coupling constant in the 1H-NMR spectrum, NOE correlations, modified Mosher's method and derivation. We have reported the structural elucidation of 1 in our previous paper. However, further investigation gave another structure for 1, which is described in this paper. Tetrapetalone A showed similar inhibitory activity against soybean lipoxygenase to the two well-known lipoxygenase inhibitors, kojic acid and NDGA, while methylated tetrapetalone A (2) showed little inhibitory activity, even at a concentration of 1 mM.