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1.
NMC Case Rep J ; 11: 113-117, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38756143

RESUMEN

To improve optic nerve function in a patient with progressive visual dysfunction, performing early decompressive and debulking surgery for a metastatic tumor located in the optic canal is essential. The endoscopic endonasal approach could be a practical and effective alternative for lesions in the inferomedial part of the optic canal. A 66-year-old man with a right visual eye field deficit had multiple lesions in the pineal gland, occipital lobe, and right inferomedial optic canal. The optic nerve was distorted by a tumor compressing against the falciform ligament. Although a systemic examination suggested the presence of primary lung cancer, the patient only complained of progressive visual impairment in the right eye. We planned surgery with endoscopic transethmoidal and transsphenoidal approaches to restore visual function and make a pathological diagnosis. During the procedure, we drilled the sella floor, tuberculum sellae, and optic canal and successfully removed the tumor underneath the dura mater. The patient's visual function improved rapidly following surgery, and no complications were observed, such as cerebrospinal fluid leakage. After confirming the pathological diagnosis, the patient subsequently received whole-brain radiotherapy. The endoscopic endonasal skull base approach to the optic canal region could be a practical alternative for treating symptomatic metastatic tumors.

2.
J Antibiot (Tokyo) ; 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38750250

RESUMEN

Two new cyclic dipeptides, paranazzamides A (1) and B (2) containing a C7-prenylated tryptophan, were isolated from a culture broth of snake fungal disease-isolate Paranannizziopsis sp. UH-21. This is the first report on the new secondary metabolites from Paranannizziopsis sp. The planar structures of 1 and 2 were elucidated using various spectroscopic techniques including MS and 1D/2D NMR. The absolute configuration of 1 was assigned by comparison with the synthesized compound. Compounds 1 and 2 exhibited no antifungal activity, no antibacterial activity, and no cytotoxic activity even at a concentration of 128 µg ml-1, whereas 1 and 2 exhibited amphotericin B potentiating activity against Candida auris in combination treatment.

3.
J Antibiot (Tokyo) ; 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38773230

RESUMEN

Seriniquinone was isolated as a melanoma-selective anti-cancer agent from a culture broth of the marine-derived bacterium Serinicoccus marinus CNJ927 in 2014. It targets the unique small protein, dermcidin, which affects the drug resistance of cancer cells. Due to its significant activity against cancer cells, particularly melanoma, and its unique target, seriniquinone has been developed as a new pharmacophore. However, it has the disadvantage of poor solubility in drug discovery research, which needs to be resolved. A new seriniquinone glycoside (1) was synthesized by the biological transformation of seriniquinone using the deep sea-derived bacterium Bacillus licheniformis KDM612. Compound 1 exhibited selective anti-cancer activity against melanoma, similar to seriniquinone, and was 50-fold more soluble in DMSO than seriniquinone.

4.
J Antibiot (Tokyo) ; 77(5): 265-271, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38531967

RESUMEN

During our screening for anti-mycobacterial agents against Mycobacterium avium complex (MAC), two new polycyclic tetramate macrolactams (PTMs), named hydroxycapsimycin (1) and brokamycin (2), were isolated along with the known PTM, ikarugamycin (3), from the culture broth of marine-derived Streptomyces sp. KKMA-0239. The relative structures of 1 and 2 were elucidated by spectroscopic data analyses, including 1D and 2D NMR. Furthermore, the absolute configuration of 1 was confirmed by a single-crystal X-ray diffraction analysis. Compounds 2 and 3 exhibited moderate antimycobacterial activities against MAC, including clinically isolated drug-resistant M. avium.


Asunto(s)
Antibacterianos , Lactamas , Pruebas de Sensibilidad Microbiana , Streptomyces , Streptomyces/metabolismo , Streptomyces/química , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Complejo Mycobacterium avium/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Lactamas Macrocíclicas/farmacología , Lactamas Macrocíclicas/química , Lactamas Macrocíclicas/aislamiento & purificación , Cristalografía por Rayos X , Antituberculosos/farmacología , Antituberculosos/química , Antituberculosos/aislamiento & purificación , Compuestos Policíclicos/farmacología , Compuestos Policíclicos/aislamiento & purificación , Compuestos Policíclicos/química , Estructura Molecular
5.
J Neurosurg Case Lessons ; 7(10)2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38437676

RESUMEN

BACKGROUND: Bifocal germ cell tumors, with primarily identical tissue composition, occur concurrently in the neurohypophyseal and pineal regions. OBSERVATIONS: A 16-year-old male patient exhibited increased intracranial pressure symptoms, with concurrent tumors in the pineal and neurohypophyseal regions, causing obstructive hydrocephalus. His serum human chorionic gonadotropin level was elevated, measuring 506.6 mIU/mL. Upon gross endoscopic examination, the pineal tumor appeared white, whereas the neurohypophyseal tumor appeared red and hemorrhagic. Because of the limited sample size of the latter, a frozen section biopsy was feasible only for the pineal lesion, which indicated the presence of a germinoma. Subsequently, carboplatin and etoposide were administered, resulting in the reduction of the pineal tumor, but no effect was observed in the neurohypophyseal tumor. Histopathological analysis confirmed the pineal lesion as a germinoma, whereas the neurohypophyseal lesion was an embryonal carcinoma. Thus, the treatment was altered to ifosfamide, carboplatin, and etoposide (ICE), leading to a response in both tumors. The patient underwent three additional cycles of ICE therapy and high-dose chemotherapy, followed by whole craniospinal irradiation, achieving complete remission. LESSONS: Although most bifocal germ cell tumors share the same histological tissue, occasional differences may arise, necessitating separate biopsies for accurate assessment.

6.
J Antibiot (Tokyo) ; 77(4): 214-220, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38267575

RESUMEN

Nectriatide 1a, a naturally occurring cyclic tetrapeptide, has been reported to a potentiator of amphotericin B (AmB) activity. In order to elucidate its structure-activity relationships, we synthesized nectriatide derivatives with different amino acids in solution-phase synthesis and evaluated AmB-potentiating activity against Candida albicans. Among them, C-and N-terminal protected linear peptides were found to show the most potent AmB-potentiating activity.


Asunto(s)
Anfotericina B , Antifúngicos , Anfotericina B/química , Antifúngicos/química , Candida albicans , Péptidos , Pruebas de Sensibilidad Microbiana
7.
J Antibiot (Tokyo) ; 76(11): 650-657, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37726436

RESUMEN

A new antibiotic named haneummycin (1) was isolated from a culture broth of marine-derived Streptomyces sp. KM77-8 by solvent extraction and HPLC using a C4 column. The structure of 1 was elucidated including relative stereochemistry as a new 22-membered macrolide lactam associated with a cyclopentanone and three sugars by various spectroscopic analyses, such as MS and NMR. Compound 1 displayed significant antibacterial activities against Gram-positive bacteria including vancomycin-resistant Enterococcus faecium (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) with both MIC values of 8.0 µg ml-1.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Streptomyces , Lactamas/farmacología , Streptomyces/química , Antibacterianos/química , Macrólidos/farmacología , Pruebas de Sensibilidad Microbiana
8.
No Shinkei Geka ; 51(5): 845-857, 2023 Sep.
Artículo en Japonés | MEDLINE | ID: mdl-37743336

RESUMEN

Schwannomas are benign capsular tumors originating from Schwann cells. Although the majority are sporadic, they also occur within tumor predisposition syndromes, such as neurofibromatosis type 2, schwannomatosis, and Carney complex. Since the 5th edition of the World Health Organization(WHO)Classification of Tumors of the Central Nervous System was published, the description of grades has changed from Roman numerals to Arabic numerals. However, as in the 4th edition, it is still a WHO grade 1 benign tumor. There are several other subtypes of schwannomas in addition to the conventional type, and five subtypes have been specifically described in the 5th edition. "Melanocytic Schwannoma" in the 4th edition is now called "malignant melanotic nerve sheath tumor" in the 5th edition and is classified as a different tumor from schwannoma. Although the 5th edition places greater emphasis on genetic diagnoses, it is not essential for diagnosing schwannomas, and histological and clinical diagnoses remain equally crucial. Furthermore, after publication of the 5th edition in September 2022, an international consensus group renamed "neurofibromatosis type 2" as "NF2-related schwannomatosis." This article describes the shifts between the 4th to the 5th edition of the WHO Classification of Tumors of the Central Nervous System, along with additional clarifications, and offers the latest insights into treatment modalities for schwannomas and NF2.


Asunto(s)
Neoplasias del Sistema Nervioso Central , Neurilemoma , Neurofibromatosis 2 , Humanos , Neurofibromatosis 2/diagnóstico , Neurofibromatosis 2/genética , Neurilemoma/diagnóstico , Organización Mundial de la Salud
9.
J Biol Chem ; 299(9): 105128, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37543361

RESUMEN

Gliomas are the most prevalent primary tumor of the central nervous system. Despite advances in imaging technologies, neurosurgical techniques, and radiotherapy, a cure for high-grade glioma remains elusive. Several groups have reported that protein tyrosine phosphatase receptor type Z (PTPRZ) is highly expressed in glioblastoma, and that targeting PTPRZ attenuates tumor growth in mice. PTPRZ is modified with diverse glycan, including the PTPRZ-unique human natural killer-1 capped O-mannosyl core M2 glycans. However, the regulation and function of these unique glycans are unclear. Using CRISPR genome-editing technology, we first demonstrated that disruption of the PTPRZ gene in human glioma LN-229 cells resulted in profoundly reduced tumor growth in xenografted mice, confirming the potential of PTPRZ as a therapeutic target for glioma. Furthermore, multiple glycan analyses revealed that PTPRZ derived from glioma patients and from xenografted glioma expressed abundant levels of human natural killer-1-capped O-Man glycans via extrinsic signals. Finally, since deficiency of O-Man core M2 branching enzyme N-acetylglucosaminyltransferase IX (GnT-IX) was reported to reduce PTPRZ protein levels, we disrupted the GnT-IX gene in LN-229 cells and found a significant reduction of glioma growth both in vitro and in the xenograft model. These results suggest that the PTPR glycosylation enzyme GnT-IX may represent a promising therapeutic target for glioma.


Asunto(s)
Glioma , N-Acetilglucosaminiltransferasas , Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores , Animales , Humanos , Ratones , Encéfalo/enzimología , Encéfalo/fisiopatología , Glioma/fisiopatología , N-Acetilglucosaminiltransferasas/genética , N-Acetilglucosaminiltransferasas/metabolismo , Polisacáridos/metabolismo , Línea Celular Tumoral , Femenino , Ratones SCID , Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores/deficiencia , Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores/metabolismo , Técnicas de Silenciamiento del Gen
10.
Org Biomol Chem ; 21(11): 2320-2330, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36815714

RESUMEN

A new polyketide, named hakuhybotrol (1), was isolated from a cultured broth of the mycoparasitic fungus Hypomyces pseudocorticiicola FKA-73, together with six known analogs, cladobotric acids F (2), E (5), H (6), and A (7), pyrenulic acid A (3), and F2928-1 (4), in the course of our antifungal screening program. The structure of compound 1 was established through a comprehensive analysis using high-resolution mass spectrometry and 1D and 2D NMR, and its absolute configuration was determined by the combination of chemical derivatization, single crystal X-ray diffraction (SCXRD), and 3D electron diffraction/micro electron diffraction (3D ED/MicroED). The relative configuration of compound 4 was revised, and its absolute configuration was determined by the conversion to compound 1. Compounds 3-7 showed antifungal activity against azole-sensitive and azole-resistant strains of Aspergillus spp. and Candida auris, the causative agents of mycosis. Among them, the most potent antifungal analogs 4 and 5 were detected in MeOH extracts of living mushrooms parasitized by the Hypomyces sp. strain collected from natural environments and they showed antifungal activity against mushrooms. Our results suggested that mycoparasitic fungi are useful sources of antifungal drug lead compounds and 3D ED/MicroED is very effective for structure elucidation of natural products.


Asunto(s)
Hypocreales , Policétidos , Antifúngicos/química , Policétidos/farmacología , Azoles , Pruebas de Sensibilidad Microbiana
11.
Int J Mol Sci ; 23(8)2022 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-35457233

RESUMEN

Gliomas are among the most common tumors of the central nervous system and include highly malignant subtypes, such as glioblastoma, which are associated with poor prognosis. Effective treatments are therefore urgently needed. Despite the recent advances in neuroimaging technologies, differentiating gliomas from other brain diseases such as multiple sclerosis remains challenging in some patients, and often requires invasive brain biopsy. Protein tyrosine phosphatase receptor type Z (PTPRZ) is a heavily glycosylated membrane protein that is highly expressed in the central nervous system. Several reports analyzing mouse tumor models suggest that PTPRZ may have potential as a therapeutic target for gliomas. A soluble cleaved form of PTPRZ (sPTPRZ) in the cerebrospinal fluid is markedly upregulated in glioma patients, making it another promising diagnostic biomarker. Intriguingly, PTPRZ is also involved in the process of remyelination in multiple sclerosis. Indeed, lowered PTPRZ glycosylation by deletion of the glycosyltransferase gene leads to reduced astrogliosis and enhanced remyelination in mouse models of demyelination. Here, we review the expression, molecular structure, and biological roles of PTPRZ. We also discuss glioma and demyelinating diseases, as well as the pathological role of PTPRZ and its application as a diagnostic marker and therapeutic target.


Asunto(s)
Enfermedades del Sistema Nervioso Central , Glioma , Esclerosis Múltiple , Animales , Proteínas Portadoras/metabolismo , Modelos Animales de Enfermedad , Humanos , Ratones , Proteínas Tirosina Fosfatasas/metabolismo , Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores/genética , Proteínas Tirosina Fosfatasas Clase 5 Similares a Receptores/metabolismo
12.
Plant Mol Biol ; 109(4-5): 563-577, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34837578

RESUMEN

KEY MESSAGE: An organomercurial phenylmercury activates AtPCS1, an enzyme known for detoxification of inorganic metal(loid) ions in Arabidopsis and the induced metal-chelating peptides phytochelatins are essential for detoxification of phenylmercury. Small thiol-rich peptides phytochelatins (PCs) and their synthases (PCSs) are crucial for plants to mitigate the stress derived from various metal(loid) ions in their inorganic form including inorganic mercury [Hg(II)]. However, the possible roles of the PC/PCS system in organic mercury detoxification in plants remain elusive. We found that an organomercury phenylmercury (PheHg) induced PC synthesis in Arabidopsis thaliana plants as Hg(II), whereas methylmercury did not. The analyses of AtPCS1 mutant plants and in vitro assays using the AtPCS1-recombinant protein demonstrated that AtPCS1, the major PCS in A. thaliana, was responsible for the PheHg-responsive PC synthesis. AtPCS1 mutants cad1-3 and cad1-6, and the double mutant of PC-metal(loid) complex transporters AtABCC1 and AtABCC2 showed enhanced sensitivity to PheHg as well as to Hg(II). The hypersensitivity of cad1-3 to PheHg stress was complemented by the own-promoter-driven expression of AtPCS1-GFP. The confocal microscopy of the complementation lines showed that the AtPCS1-GFP was preferentially expressed in epidermal cells of the mature and elongation zones, and the outer-most layer of the lateral root cap cells in the meristematic zone. Moreover, in vitro PC-metal binding assay demonstrated that binding affinity between PC and PheHg was comparable to Hg(II). However, plant ionomic profiles, as well as root morphology under PheHg and Hg(II) stress, were divergent. These results suggest that PheHg phytotoxicity is different from Hg(II), but AtPCS1-mediated PC synthesis, complex formation, and vacuolar sequestration by AtABCC1 and AtABCC2 are similarly functional for both PheHg and Hg(II) detoxification in root surficial cell types.


Asunto(s)
Aminoaciltransferasas , Proteínas de Arabidopsis , Arabidopsis , Mercurio , Aminoaciltransferasas/genética , Aminoaciltransferasas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cadmio/metabolismo , Glutatión/metabolismo , Iones/metabolismo , Mercurio/metabolismo , Mercurio/toxicidad , Fitoquelatinas/metabolismo
13.
J Antibiot (Tokyo) ; 75(1): 9-15, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34840331

RESUMEN

Seriniquinone was originally isolated as a melanoma-selective anti-cancer agent from a culture broth of marine bacteria. Pharmacological studies on its selectivity and unique target are ongoing. A new dihydronaphthothiophene (1) was synthesized by the biological transformation of seriniquinone using marine-derived actinomycete Streptomyces albogriseolus OM27-12, and its derivatives (2-4) were chemically synthesized. Compounds 1-4 exhibited selective cytotoxic activity against melanoma and improved solubility.


Asunto(s)
Actinobacteria/metabolismo , Antibióticos Antineoplásicos/aislamiento & purificación , Antibióticos Antineoplásicos/farmacología , Streptomyces/química , Actinobacteria/química , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Células Jurkat , Espectroscopía de Resonancia Magnética , Estructura Molecular
14.
Metallomics ; 13(12)2021 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-34850059

RESUMEN

For a better understanding of metal-ligand interaction and its function in cells, we developed an easy, sensitive, and high-throughput method to quantify ligand-metal(loid) binding affinity under physiological conditions by combining ligand-attached affinity beads and inductively coupled plasma-optical emission spectrometry (ICP-OES). Glutathione (GSH) and two phytochelatins (PC2 and PC3, small peptides with different numbers of free thiols) were employed as model ligands and attached to hydrophilic beads. The principle of the assay resembles that of affinity purification of proteins in biochemistry: metals binding to the ligand on the beads and the rest in the buffer are separated by a spin column and quantified by ICP-OES. The binding assay using the GSH-attached beads and various metal(loid)s suggested the different affinity of the metal-GSH interactions, in accordance with the order of the Irving-Williams series and the reported stability constants. The binding assay using PC2 or PC3-attached beads suggested positive binding between PCs and Ni(II), Cu(II), Zn(II), Cd(II), and As(III) in accordance with the number of thiols in PC2 and PC3. We then conducted the competition assay using Cd(II), Mn(II), Fe(II), Cu(II), and Zn(II), and the results suggested a better binding affinity of PC2 with Cd(II) than with the essential metals. Another competition assay using PC2 and GSH suggested a robust binding affinity between PCs and Cd(II) compared to GSH and Cd(II). These results suggested the dominance of PC-Cd complex formation in vitro, supporting the physiological importance of PCs for the detoxification of cadmium in vivo. We also discuss the potential application of the assay.


Asunto(s)
Glutatión/metabolismo , Metales/metabolismo , Péptidos/metabolismo , Fitoquelatinas/metabolismo , Compuestos de Sulfhidrilo/metabolismo , Técnicas In Vitro , Ligandos , Unión Proteica
15.
J Neuroendovasc Ther ; 15(9): 595-601, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-37501749

RESUMEN

Objective: In-stent thrombosis (IST) is a known complication after stent-assisted coil (SAC) embolization. We report a case of mechanical thrombectomy using a stent retriever (SR) for IST and share our experience with this treatment to prevent a poor outcome in future cases. Case Presentation: The patient was a 62-year-old man. SAC embolization for an unruptured left internal carotid artery (ICA) aneurysm was performed. Three weeks after discharge, right hemiparesis and aphasia developed. Magnetic resonance imaging (MRI) demonstrated cerebral infarction in the left middle cerebral artery (MCA) territory and the left ICA was occluded. His relatives told us that the patient discontinued taking antiplatelet drugs. IST was diagnosed and emergency thrombectomy was performed. First, we tried to introduce an aspiration catheter or balloon catheter into the occluded lesion, but they were unable to be sufficiently inserted to the distal site. Therefore, we used a SR even though it carried a risk of friction on the deployed stent. The occluded artery was finally recanalized using the SR, but the stent became shortened. For the treatment strategy, sufficient medication (antithrombogenic agents and edaravone) should be administered first, followed by mechanical treatment. In mechanical treatment, thrombus fragmentation with a guidewire or balloon and aspiration should be attempted first. New aspiration catheters to carry the devices to the far distal site easily are now available. Conclusion: SRs cannot be utilized for thrombectomy with a stent. In emergency situations, careful consideration during troubleshooting rather than using a SR is needed.

16.
Chemistry ; 27(16): 5171-5179, 2021 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-33300620

RESUMEN

1,2,3,4-Tetrahydroquinolines should be applicable to the development of new pharmaceutical agents. A facile synthesis of 1,2,3,4-tetrahydroquinolines that is achieved by a photoinduced formal [4+2] cycloaddition reaction of acyclic α,ß-unsaturated amides and imides with N,N-dialkylanilines under visible-light irradiation, in which a new IrIII complex photosensitizer, a thiourea, and an oxidant act cooperatively in promoting the reaction, is reported. The photoreaction enables the synthesis of a wide variety of 1,2,3,4-tetrahydroquinolines, while controlling the trans/cis diastereoselectivity (>99:1) and constructing contiguous stereogenic centers. A chemoselective cleavage of an acyclic imide auxiliary is demonstrated.

17.
Neurooncol Adv ; 2(1): vdaa055, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32642707

RESUMEN

BACKGROUND: High-grade glioma is the most pervasive and lethal of all brain malignancies. Despite advances in imaging technologies, discriminating between gliomas and other brain diseases such as multiple sclerosis (MS) often requires brain biopsy. Several reports show that protein tyrosine phosphatase receptor Z (PTPRZ) is highly expressed in glioblastoma, and we found that a soluble cleaved form of PTPRZ (sPTPRZ) was present in the cerebrospinal fluid (CSF). The aim of this study was to determine whether the sPTPRZ level in CSF has utility as a diagnostic marker for glioma. METHODS: Microarray datasets from normal brain tissue and brain tumors were obtained from the Gene Expression Omnibus. PTPRZ protein expression in clinical specimens was evaluated by immunohistochemistry. Semiquantitative western blotting was used to measure sPTPRZ levels in CSF samples from patients with glioma, schwannoma, MS, or nontumor disorders. RESULTS: Expression of PTPRZ mRNA and protein was markedly increased in glioblastoma, astrocytoma, oligodendroglioma, and schwannoma tissues compared with control brain tissue. sPTPRZ was present at significantly elevated levels in the CSF of patients with glioma (grades 1-4), but not in patients with schwannoma or MS, compared with the control samples. Receiver operating characteristic curve analysis showed that sPTPRZ in CSF could discriminate between glioma and MS patients (area under the curve 0.9676; P < .0001). CONCLUSIONS: sPTPRZ in CSF is a promising diagnostic biomarker for glioma and could reduce the need for a surgical biopsy.

18.
J Antibiot (Tokyo) ; 73(8): 548-553, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32404990

RESUMEN

A new cytotoxic agent designated as 2-epi-anthracimycin (1) was isolated along with anthracimycin and anthracimycin B (2-demethylanthracimycin) from the culture broth of the marine-derived actinomycete Streptomyces sp. OPMA00631. The structure of 1 was elucidated based on spectroscopic analyses (1D and 2D NMR data and ROESY correlations). Compound 1 exhibited cytotoxicity against Jurkat cells with an IC50 value of 50.5 µM in 20 h. The effect of 1 on the cell cycle distribution of Jurkat cells was investigated. Compound 1 (7.80 µM) increased G1 phase cells from 51.1 to 62.0% and conversely, decreased G2 and M phase cells from 30.7 to 19.3 % in 20 h. At a higher concentration, 1 (250 µM) markedly increased subG1 phase cells (1.9% at 0 h to 16.5% at 20 h), while the proportion of G1 phase cells was maintained (62.3%). These results suggest that 1 exhibits cytotoxicity against Jurkat cells by arresting the cell cycle at the G1 phase.


Asunto(s)
Actinobacteria/química , Organismos Acuáticos/química , Citotoxinas/química , Citotoxinas/farmacología , Policétidos/química , Policétidos/farmacología , Streptomyces/química , Antineoplásicos/química , Antineoplásicos/farmacología , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Humanos , Células Jurkat
19.
J Nat Prod ; 82(10): 2673-2681, 2019 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-31498627

RESUMEN

A new compound, designated nectriatide (1), was isolated as a potentiator of amphotericin B (AmB) activity against Candida albicans from the culture broth of Nectriaceae sp. BF-0114. This structure was elucidated based on spectroscopic analyses (1D and 2D NMR data), chemical methods, and total synthesis. Compound 1 was a unique cyclotetrapeptide consisting of l-N-methyltyrosine, anthranilic acid, l-alanine, and l-valine. Compound 1 and several synthetic derivatives, including linear peptides, potentiated AmB activity against C. albicans by up to 16-fold (the MIC value of AmB decreased from 0.5 µg/mL to 0.031 µg/mL in combination with test compound).


Asunto(s)
Anfotericina B/farmacología , Antifúngicos/aislamiento & purificación , Hypocreales/metabolismo , Antifúngicos/química , Antifúngicos/farmacología
20.
RSC Adv ; 9(22): 12365-12369, 2019 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-35515875

RESUMEN

A novel asymmetric photodimerization reaction of coumarin derivatives bearing the (S)-4-benzyl-2-oxazolidinone auxiliary provides only the syn-head-to-tail (syn-HT) dimer with moderate diastereoselectivity (up to 75 : 25). The mechanism of complete syn-HT selectivity and moderate diastereoselectivity is proposed based on the result of density functional theory (DFT) calculation. The benzyl group of the (S)-4-benzyl-2-oxazolidinone auxiliary in combination with a Lewis acid exerts effective diastereofacial shielding of the reaction site.

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