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Abstract
Protein phosphatases play essential roles as negative regulators of kinases and signaling cascades involved in cytoskeletal organization. Protein phosphatase 2A (PP2A) is highly conserved and is the predominant serine/threonine phosphatase in the nervous system, constituting more than 70% of all neuronal phosphatases. PP2A is involved in diverse regulatory functions, including cell cycle progression, apoptosis, and DNA repair. Although PP2A has historically been identified as a tumor suppressor, inhibition of PP2A has paradoxically demonstrated potential as a therapeutic target for various cancers. LB100, a water-soluble, small-molecule competitive inhibitor of PP2A, has shown particular promise as a chemo- and radio-sensitizing agent. Preclinical success has led to a profusion of clinical trials on LB100 adjuvant therapies, including a phase I trial in extensive-stage small-cell lung cancer, a phase I/II trial in myelodysplastic syndrome, a phase II trial in recurrent glioblastoma, and a completed phase I trial assessing the safety of LB100 and docetaxel in various relapsed solid tumors. Herein, we review the development of LB100, the role of PP2A in cancer biology, and recent advances in targeting PP2A inhibition in immunotherapy.
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Affiliation(s)
- Halle Ronk
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jared S. Rosenblum
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Timothy Kung
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhengping Zhuang
- Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Foley AR, Finn TS, Kung T, Hatami A, Lee HW, Jia M, Rolandi M, Raskatov JA. Trapping and Characterization of Nontoxic Aβ42 Aggregation Intermediates. ACS Chem Neurosci 2019; 10:3880-3887. [PMID: 31319029 DOI: 10.1021/acschemneuro.9b00340] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Amyloid β (Aβ) 42 is an aggregation-prone peptide and the believed seminal etiological agent of Alzheimer's disease (AD). Intermediates of Aβ42 aggregation, commonly referred to as diffusible oligomers, are considered to be among the most toxic forms of the peptide. Here, we studied the effect of the age-related epimerization of Ser26 (i.e., S26s chiral edit) in Aβ42 and discovered that this subtle molecular change led to reduced fibril formation propensity. Surprisingly, the resultant soluble aggregates were nontoxic. To gain insight into the structural changes that occurred in the peptide upon S26s substitution, the system was probed using an array of biophysical and biochemical methods. These experiments consistently pointed to the stabilization of aggregation intermediates in the Aβ42-S26s system. To better understand the changes arising as a consequence of the S26s substitution, molecular level structural studies were performed. Using a combined nuclear magnetic resonance (NMR)- and density functional theory (DFT)-computational approach, we found that the S26s chiral edit induced only local structural changes in the Gly25-Ser26-Asn27 region. Interestingly, these subtle changes enabled the formation of an intramolecular Ser26-Asn27 H-bond, which disrupted the ability of Asn27 to engage in the fibrillogenic side chain-to-side chain H-bonding pattern. This reveals that intermolecular stabilizing interactions between Asn27 side chains are a key element controlling Aβ42 aggregation and toxicity.
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Affiliation(s)
- Alejandro R. Foley
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Thomas S. Finn
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Timothy Kung
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Asa Hatami
- Sangamo Therapeutics, Richmond, California 94804, United States
| | - Hsiau-Wei Lee
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Manping Jia
- Department of Electrical Engineering, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Marco Rolandi
- Department of Electrical Engineering, University of California Santa Cruz, Santa Cruz, California 95064, United States
| | - Jevgenij A. Raskatov
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, United States
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Medrek S, Sahay S, Kung T, Zhao C, Frost A. Relationship between Race/Ethnicity and Survival in Patients with Pulmonary Arterial Hypertension (PAH). J Heart Lung Transplant 2019. [DOI: 10.1016/j.healun.2019.01.223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Szabó T, Scherbakov N, Sandek A, Kung T, von Haehling S, Lainscak M, Jankowska EA, Rudovich N, Anker SD, Frystyk J, Flyvbjerg A, Pfeiffer AFH, Doehner W. Plasma adiponectin in heart failure with and without cachexia: catabolic signal linking catabolism, symptomatic status, and prognosis. Nutr Metab Cardiovasc Dis 2014; 24:50-56. [PMID: 23791298 DOI: 10.1016/j.numecd.2013.04.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 03/05/2013] [Accepted: 04/17/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND AND AIMS Adiponectin (ADPN) as an adipose tissue hormone contributes to regulation of energy metabolism and body composition and is associated with cardiovascular risk profile parameters. Cardiac cachexia may develop as a result of severe catabolic derangement in chronic heart failure (CHF). We aimed to determinate an abnormal ADPN regulation as a link between catabolic signalling, symptomatic deterioration and poor prognosis. METHODS AND RESULTS We measured plasma ADPN in 111 CHF patients (age 65 ± 11, 90% male, left ventricular ejection fraction (LVEF) 36 ± 11%, peak oxygen consumption (peakVO2) 18.1 ± 5.7 l/kg*min, body mass index (BMI) 27 ± 4 kg/m(2), all mean ± standard deviation) and 36 healthy controls of similar age and BMI. Body composition was assessed by dual energy X-ray absorptiometry, insulin sensitivity was evaluated by homoeostasis model assessment, exercise capacity by spiroergometry. Plasma ADPN did not differ between CHF vs. controls (13.5 ± 11.0 vs. 10.5 ± 5.3 mg/l, p > 0.4), but increased stepwise with NYHA functional class (I/II/III: 5.7 ± 1.4/10.7 ± 8.3/19.2 ± 14.0 mg/l, ANOVA p < 0.01). Furthermore, ADPN correlated with VO2 at anaerobic threshold (r = -0.34, p < 0.05). ADPN was highest in cachectic patients (cCHF, 16%) vs. non-cachectic (ncCHF) (18.7 ± 15.0 vs. 12.5 ± 9.9 mg/l; p < 0.05). ADPN indicated mortality risk independently of established prognosticators (HR: 1.04 95% CI: 1.02-1.07; p < 0.0001). ADPN above the mean (13.5 mg/l) was associated with a 3.4 times higher mortality risk in CHF vs. patients with ADPN levels below the mean. CONCLUSION Circulating ADPN is abnormally regulated in CHF. ADPN may be involved in impaired metabolic signalling linking disease progression, tissue wasting, and poor outcome in CHF.
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Affiliation(s)
- T Szabó
- Applied Cachexia Research, Department of Cardiology, Charite Universitätsmedizin Berlin, Germany
| | - N Scherbakov
- Centre for Stroke Research Berlin, Charite Universitätsmedizin Berlin, Germany
| | - A Sandek
- Applied Cachexia Research, Department of Cardiology, Charite Universitätsmedizin Berlin, Germany
| | - T Kung
- Applied Cachexia Research, Department of Cardiology, Charite Universitätsmedizin Berlin, Germany
| | - S von Haehling
- Applied Cachexia Research, Department of Cardiology, Charite Universitätsmedizin Berlin, Germany
| | - M Lainscak
- Division of Cardiology, University Clinic, Golnik, Slovenia
| | - E A Jankowska
- Department of Heart Diseases, Wroclaw Medical University, Wroclaw, Poland
| | - N Rudovich
- Department of Endocrinology, Diabetes, and Nutritional Medicine, Universitätsmedizin Berlin, Germany
| | - S D Anker
- Centre for Clinical and Basic Research, IRCCS San Raffaele, Rome, Italy
| | - J Frystyk
- Department of Endocrinology and Internal Medicine & the Medical Research Laboratories, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - A Flyvbjerg
- Department of Endocrinology and Internal Medicine & the Medical Research Laboratories, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - A F H Pfeiffer
- Department of Endocrinology, Diabetes, and Nutritional Medicine, Universitätsmedizin Berlin, Germany
| | - W Doehner
- Applied Cachexia Research, Department of Cardiology, Charite Universitätsmedizin Berlin, Germany; Centre for Stroke Research Berlin, Charite Universitätsmedizin Berlin, Germany.
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Spond J, Case N, Chapman RW, Crawley Y, Egan RW, Fine J, Hey JA, Kreutner W, Kung T, Wang P, Minnicozzi M. Inhibition of experimental acute pulmonary inflammation by pirfenidone. Pulm Pharmacol Ther 2003; 16:207-14. [PMID: 12850123 DOI: 10.1016/s1094-5539(03)00026-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pirfenidone, a putative tumor necrosis factor-alpha (TNF-alpha) inhibitor, has recently gained recognition for its therapeutic use in the treatment of idiopathic pulmonary fibrosis. As pulmonary fibrosis may be the result of lung inflammatory processes, we examined the anti-inflammatory potential of pirfenidone in several models of acute pulmonary inflammation. In antigen-induced allergic paradigms, 24 h after antigen challenge, sensitized mice or guinea pigs develop a prominent pulmonary inflammation, reflected by a significant increase in the number of recoverable bronchoalveolar lavage (BAL) total cells and eosinophils. In both species, the pretreatment of animals with pirfenidone (10 and 30 mg/kg) resulted in a dose-dependent inhibition of the antigen-induced pulmonary inflammation, which was reflected by a significant decrease in the BAL eosinophils and total cells by the 30 mg/kg dose. In a non-allergic model of pulmonary inflammation, rats challenged with intratracheal LPS develop a significant increase in BAL neutrophils and total cells, along with significant increases in TNF-alpha and IL-6. Pretreatment with pirfenidone (3 and 30 mg/kg) showed a dose-dependent inhibition of the LPS-induced pulmonary inflammation, reflected by a significant decrease in the number of BAL total and neutrophilic cells at both the 3 and 30 mg/kg dose. However, pirfenidone had no effect on the peak BAL levels of TNF-alpha. In contrast, pirfenidone significantly inhibited BAL levels of IL-6. In summary, we have shown that pirfenidone can inhibit allergic and non-allergic inflammatory cell recruitment and that its pulmonary anti-inflammatory activity is independent of TNF-alpha inhibition.
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Affiliation(s)
- J Spond
- Schering Plough Research Institute, Allergy and Immunology, 2015 Galloping Hill Road, K-15-1600, Kenilworth, NJ 07033, USA
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Abstract
The growth and buoyant densities of two closely related strains of Escherichia coli in M9-glucose medium that was diluted to produce osmolarities that varied from as low as 5 to 500 mosM were monitored. At 15 mosM, the lowest osmolarity at which buoyant density could be measured reproducibly in Percoll gradients, both ML3 and ML308 had a buoyant density of about 1.079 g/ml. As the osmolarity of the medium was increased, the buoyant density also increased linearly up to about 125 mosM, at which the buoyant density was 1.089 g/ml. From 150 up to 500 mosM, the buoyant density again increased linearly but with a different slope from that seen at the lower osmolarities. The buoyant density at 150 mosM was about 1.091 g/ml, and at 500 mosM it was 1.101 g/ml. Both strains of E. coli could be grown in M9 medium diluted 1:1 with water, with an osmolarity of 120 mosM, but neither strain grew in 1:2-diluted M9 if the cells were pregrown in undiluted M9. (Note: undiluted M9 as prepared here has an osmolarity of about 250 mosM.) However, if the cells were pregrown in 30% M9, about 75 mosM, they would then grow in M9 at 45 mosM and above but not below 40 mosM. To determine which constituent of M9 medium was being diluted to such a low level that it inhibited growth, diluted M9 was prepared with each constituent added back singly. From this study, it was determined that both Ca2+ and Mg2+ could stimulate growth below 40 mosM. With Ca2+ - and Mg2+ -supplemented diluted M9 and cells pregrown in 75 mosM M9, it was possible to grow ML308 in 15 mosM M9. Strain ML3 would only haltingly grow at 15 mosM. Four attempts were made to grow both ML3 and ML308 at 5 mosM. In three of the experiments, ML308 grew, while strain ML3 grew in one experiment. While our experiments were designed to effect variations in medium osmolarity by using NaCl as an osmotic agent, osmolarity and salinity were changed concurrently. Therefore, from this study, we believe that E. coli might be defined as an euryhalinic and/or euryosmotic bacterium because of its ability to grow in a wide range of salinities and osmolarities.
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Affiliation(s)
- W W Baldwin
- Northwest Center for Medical Education, Indiana University School of Medicine, Bloomington 47405
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Mauser PJ, Pitman A, Witt A, Fernandez X, Zurcher J, Kung T, Jones H, Watnick AS, Egan RW, Kreutner W. Inhibitory effect of the TRFK-5 anti-IL-5 antibody in a guinea pig model of asthma. Am Rev Respir Dis 1993; 148:1623-7. [PMID: 7504892 DOI: 10.1164/ajrccm/148.6_pt_1.1623] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
To investigate the role of IL-5 in airway hyperreactivity and pulmonary eosinophilia, we used a model of allergic asthma in guinea pigs and a neutralizing monoclonal antibody (TRFK-5) directed against murine IL-5. Sensitized guinea pigs were challenged with 1% ovalbumin (OVA) aerosol and assessed for airway eosinophilia (by bronchoalveolar lavage [BAL] and histologic evaluation of airway tissue) and bronchoconstrictor responsiveness to substance P (SP) (as RL100 and Cdyn40) 24 h later. OVA challenge of sensitized animals caused a significant increase in airway responsiveness to SP, with a 4.9-fold decrease in RL100 and a 4.7-fold decrease in Cdyn40. Accompanying this increased sensitivity to SP was a 9-fold increase in eosinophils recovered in BAL and a 4- to 5-fold increase in eosinophils in intrapulmonary bronchial tissue. Intraperitoneal treatment with 10 mg/kg of the IL-5 antibody 2 h before OVA challenge blocked BAL and lung tissue increases in eosinophils but had no effect on the development of airway sensitivity to SP. In contrast, similar treatment with 30 mg/kg of this antibody blocked OVA-induced increased sensitivity to SP as well as BAL and lung tissue eosinophilia. These data suggest a critical and possibly independent role for IL-5 in allergic airway hyperresponsiveness and the accumulation of eosinophils within the lung of the guinea pig.
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Affiliation(s)
- P J Mauser
- Schering-Plough Research Institute, Kenilworth, NJ 07033-0539
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Abstract
Sch 40120 (10-(3-chlorophenyl) - 6,8,9,10- tetrahydrobenzo [b] [1,8] naphthyridin-5 (7H)-one) is a leukotriene inhibitor that is also a potent inhibitor of acute inflammatory responses in rodent systems. In the present study, we have evaluated the effects of this drug on immune function as well as its activity in models of immune mediated chronic inflammatory disease. Sch 40120 was particularly effective in suppressing T cell proliferative responses in vitro. Antigen-specific and poly-clonally-induced in vitro antibody responses were also inhibited by the drug. However, the in vivo potency of Sch 40120 in suppressing immune responses and in inhibiting the pathological changes seen in rodent models of autoimmune disease (EAE and adjuvant arthritis) was somewhat less than that previously observed in models of acute inflammation. Nevertheless, the spectrum of activities exhibited by Sch 40120 suggests that it will be particularly useful in the treatment of psoriasis where T lymphocytes have been implicated in the development of disease and leukotrienes appear to have a role in the persistence of psoriatic plaques.
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Affiliation(s)
- S R Smith
- Schering Plough Research Institute, Bloomfield, NJ 07003
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Gulbenkian AR, Egan RW, Fernandez X, Jones H, Kreutner W, Kung T, Payvandi F, Sullivan L, Zurcher JA, Watnick AS. Interleukin-5 modulates eosinophil accumulation in allergic guinea pig lung. Am Rev Respir Dis 1992; 146:263-6. [PMID: 1626810 DOI: 10.1164/ajrccm/146.1.263] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Based on its involvement in eosinophil biology, interleukin 5 (IL-5) may play a role in the pulmonary eosinophilia associated with allergic reactions. We have examined that hypothesis using a neutralizing antibody to IL-5 in ovalbumin-sensitized guinea pigs challenged with aerosolized antigen. The extent of eosinophilia has been quantitated in bronchoalveolar lavage (BAL) and by histologic evaluation of lung tissue sections. Acute intraperitoneal administration of a rat IgG, monoclonal antibody to murine IL-5 derived from TRFK-5 cells prevented lung and BAL eosinophilia in a dose-dependent fashion at and above 10 micrograms per guinea pig. Treatment with either an experimentally irrelevant, isotype-matched antibody from GL113 cells or with heat-denatured IL-5 antibody was without effect. These studies demonstrate the importance of IL-5 to pulmonary eosinophilia in challenged, allergic guinea pigs.
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Affiliation(s)
- A R Gulbenkian
- Schering-Plough Research, Allergy and Cell Biology, Bloomfield, New Jersey 07003
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Gulbenkian AR, Fernandez X, Kreutner W, Minnicozzi M, Watnick AS, Kung T, Egan RW. Anaphylactic challenge causes eosinophil accumulation in bronchoalveolar lavage fluid of guinea pigs. Modulation by betamethasone, phenidone, indomethacin, WEB 2086, and a novel antiallergy agent, SCH 37224. Am Rev Respir Dis 1990; 142:680-5. [PMID: 2117872 DOI: 10.1164/ajrccm/142.3.680] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Eosinophil infiltration into bronchoalveolar areas of the lung has been assessed in guinea pigs sensitized to ovalbumin (OA) and then challenged with the aerosolized antigen. Cell content, histamine, and guinea pig albumin (GPA) have been measured in bronchoalveolar lavage (BAL) fluid from these animals. Extensive eosinophil accumulation resulted from sensitization followed by OA challenge; monocytes that initially accounted for greater than 80% of the BAL cells remained essentially constant, and neutrophils comprised less than 3% of the population throughout. Eosinophils were elevated at 3 h, peaked with a fivefold increase at 24 h, and remained elevated for at least 7 days. Histopathologic changes observed in lungs taken from sensitized guinea pigs 24 h after OA challenge confirm this eosinophilia. Increased histamine and GPA were detected only at 5 min. Oral treatment with betamethasone (ED50 = 0.4 mg/kg), phenidone (ED50 = 15 mg/kg), Sch 37224 (ED50 = 0.5 mg/kg), and WEB 2086 (ED50 = 4 mg/kg) decreased eosinophil accumulation in the BAL fluid, indicating roles for 5-lipoxygenase products and PAF in this multimediator-dependent model of allergic inflammation. On the other hand, 4 mg/kg of indomethacin increased total cells with no effect on eosinophils, precluding a major role for cyclooxygenase products. Sch 37224, an antileukotriene agent and an orally active novel antiallergy agent in sheep, guinea pigs, and humans, is as potent as betamethasone at blocking eosinophil infiltration, suggesting that it may also suppress human pulmonary inflammation.
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Affiliation(s)
- A R Gulbenkian
- Department of Allergy and Inflammation, Schering-Plough Research, Bloomfield, NJ 07003
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Gullo V, Conover M, Cooper R, Federbush C, Horan AC, Kung T, Marquez J, Patel M, Watnick A. Sch 36605, a novel anti-inflammatory compound. Taxonomy, fermentation, isolation and biological properties. J Antibiot (Tokyo) 1988; 41:20-4. [PMID: 3346189 DOI: 10.7164/antibiotics.41.20] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A novel anti-inflammatory compound, Sch 36605, belonging to the blasticidin family of nucleoside compounds was isolated from the fermentation filtrate of a Streptomyces sp. Sch 36605, as well as blasticidin S, demonstrated anti-inflammatory activity in the reverse passive Arthus reaction and the adjuvant arthritic rat at doses ranging between 1-10 mg/kg and 0.3-6.0 mg/kg, respectively. A minor component, Sch 366606, co-produced in the in the fermentation was isolated and identified as a known compound in the blasticidin family of compounds.
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Affiliation(s)
- V Gullo
- Pharmaceutical Research Division, Schering Plough Corporation, Bloomfield, New Jersey 07003
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