ABSTRACT
Seaweeds of the red algal genus Laurencia are widely distributed worldwide in tropical, subtropical to temperate zones, and grow in Japan from Hokkaido to Okinawa. Laurencia is one of the most studied seaweeds by organic chemists because it produces a variety of compounds with unique structures. In Japan, various halogenated compounds have been found in Laurencia, while some species do not produce any halogenated compounds. Laurencia is one of the most difficult seaweeds to classify morphologically; however, the major halogenated secondary metabolites produced tend to be species-specific, and these compounds can be used as chemical markers for chemical systematics (chemotaxonomy). Similarly, it has been confirmed that domestic Laurencia species produce species-specific halogenated compounds of certain types. Laurencia is one of the "weedy seaweeds" that have not been effectively utilized at present, but it produces a wide variety of metabolites, so there is a good possibility that compounds with specific activity may be found. Thus, it can be seen that the secondary metabolites in Laurencia have many interesting aspects. In this review, we reported significant morphological features to distinguish species in this genus, and the morphological features, habitat, distribution, and chemical composition that help discriminate Japanese Laurencia species.
ABSTRACT
CALCIUM-DEPENDENT PROTEIN KINASE (CDPK) stimulates reactive oxygen species (ROS)-dependent signaling by activating RESPIRATORY BURST OXIDASE HOMOLOG (RBOH). The lysigenous aerenchyma is a gas space created by cortical cell death that facilitates oxygen diffusion from the shoot to the root tips. Previously, we showed that RBOHH is indispensable for the induction of aerenchyma formation in rice (Oryza sativa) roots under low-oxygen conditions. Here, we showed that CDPK5 and CDPK13 localize to the plasma membrane where RBOHH functions. Mutation analysis of the serine at residues 92 and 107 of RBOHH revealed that these residues are required for CDPK5- and CDPK13-mediated activation of ROS production. The requirement of Ca2+ for CDPK5 and CDPK13 function was confirmed using in vitro kinase assays. CRISPR/Cas9-based mutagenesis of CDPK5 and/or CDPK13 revealed that the double knockout almost completely suppressed inducible aerenchyma formation, whereas the effects were limited in the single knockout of either CDPK5 or CDPK13. Interestingly, the double knockout almost suppressed the induction of adventitious root formation, which is widely conserved in vascular plants, under low-oxygen conditions. Our results suggest that CDPKs are essential for the acclimation of rice to low-oxygen conditions, and also for many other plant species conserving CDPK-targeted phosphorylation sites in RBOH homologues.
ABSTRACT
Toward human immunodeficiency virus type-1 (HIV-1) cure, cells latently infected with HIV-1 must be eliminated from people living with HIV-1. We previously developed a protein kinase C (PKC) activator, diacylglycerol (DAG)-lactone derivative 3, with high HIV-1 latency-reversing activity, based on YSE028 (2) as a lead compound and found that the activity was correlated with binding affinity for PKC and stability against esterase-mediated hydrolysis. Here, we synthesized new DAG-lactone derivatives not only containing a tertiary ester group or an isoxazole surrogate but also several symmetric alkylidene moieties to improve HIV-1 latency reversing activity. Compound 9a, with a dimethyl group at the α-position of the ester group, exerted twice higher HIV-1 latency reversing activity than compound 3, and compound 26, with the isoxazole moiety, was significantly active. In addition, DAG-lactone derivatives with moderate hydrophobicity and potent biostability showed high biological activity.
Subject(s)
Anti-HIV Agents , HIV-1 , Lactones , Virus Latency , Humans , HIV-1/drug effects , HIV-1/physiology , Virus Latency/drug effects , Lactones/pharmacology , Lactones/chemistry , Lactones/chemical synthesis , Anti-HIV Agents/pharmacology , Anti-HIV Agents/chemistry , Anti-HIV Agents/chemical synthesis , Diglycerides/chemistry , Diglycerides/pharmacology , Diglycerides/chemical synthesis , HIV Infections/drug therapy , HIV Infections/virology , Protein Kinase C/metabolism , Protein Kinase C/antagonists & inhibitorsABSTRACT
The red algal genus Portieria is a prolific producer of halogenated monoterpenoids. In this study, we isolated and characterised monoterpenoids from the Okinawan red algae Portieria hornemannii. A new polyhalogenated cyclic monoterpenoid, 2(R)-chloro-1,6(S)-dibromo-3(8)(Z)-ochtoden-4(R)-ol (1), along with three known monoterpenoids, (2R,3(8)E,4S,6R)-6-bromo-2-chloro-1,4-oxido-3(8)-ochtodene (2), 1-bromo-2-chloroochtoda-3(8),5-dien-4-one (3), and 2-chloro-1-hydroxyochtoda-3(8),5-dien-4-one (4) were isolated from the methanol extract of three populations of P. hornemannii. These compounds were characterised using a combination of spectroscopic methods and chemical synthesis, and the absolute stereochemistry of compounds 1 and 2 was determined. In addition, all isolated compounds were screened for their anti-biofouling activity against the mussel Mytilus galloprovincialis, and 1 exhibited strong activity. Therefore, halogenated monoterpenoids have the potential to be used as natural anti-biofouling drugs.
Subject(s)
Biofouling , Monoterpenes , Rhodophyta , Animals , Biofouling/prevention & control , Halogenation , Molecular Structure , Monoterpenes/isolation & purification , Monoterpenes/chemistry , Monoterpenes/pharmacology , Rhodophyta/chemistry , Guanethidine/chemistry , Guanethidine/isolation & purification , Guanethidine/pharmacologyABSTRACT
Actinomycetes are well-known as the main producers of bioactive compounds such as antibiotics, anticancers, and immunosuppressants. Screening of natural products from actinomycetes has been an essential part of several drug discovery programs. Finding such novel biologically active metabolites is immensely important because of their beneficial health effects. Recently, the discovery of new compounds has diverted attention to rare actinomycetes, since they are rich sources of natural products. In this study, a collection of rare actinomycetes at Kitasato University has been screened for potential novel compound producers. Among the rare actinomycetes, Saccharopolyspora sp. KR21-0001 isolated from soil on Oha Island, Okinawa, Japan was selected as a potential producer. The strain was cultured in 20 L of production medium in a jar fermenter and the culture broth was extracted. Further purification revealed the presence of a new compound designated KR21-0001A (1). The structure was elucidated by NMR, and the absolute stereochemistry was determined by advanced Marfey's method. The results indicated that 1 is a new analog of dihydroxybenzoic acid. 1 has no antimicrobial activity against bacteria and fungi but showed potent antioxidant activity.
ABSTRACT
An improvement of the two-photon excitation was achieved using 8-azacoumarin-type caged compounds, which showed large values of the two-photon uncaging action cross-section (δu >0.1 Goeppert-Mayer (GM)). In particular, the 7-hydroxy-6-iodo-8-azacoumarin (8-aza-Ihc)-caged compound showed an excellent uncaging action cross-section value (δu = 1.28 GM). Therefore, 8-azacoumarin-type photolabile protecting groups (PPGs) can be used as two-photon excitation sources.
Subject(s)
PhotonsABSTRACT
PURPOSE: This retrospective study was performed to investigate the recent trend of occurrence of cancer of the remnant colorectal segment(RCRS)after ileal-pouch anal anastomosis(IPAA)/ileorectal anastomosis(IRA)and to consider the optimal surveillance methods in patients with familial adenomatous polyposis(FAP)undergoing(procto)colectomy. PATIENTS AND METHODS: The subject was a total of patients with FAP undergoing IPAA or IRA between 2005 and 2022. Clinicopathological data were extracted from medical charts and analyzed. Cumulative incidence of cancer in the RCRS and overall survival after treatment of such tumors were calculated by the Kaplan-Meier method. RESULTS: There were 45 male and 56 female. IPAA was performed in 49 patients(hand-sewn; n=33, stapled; n=16)and IRA was performed in 52 patients. The median age at initial colorectal surgery was 32 years old(range, 13-66 years old). Median postoperative follow-up was 11 years(range, 1-48 years). Eighty-one patients were confirmed to have pathogenic variant of APC by genetic test. The cumulative incidence of cancer of the RCRS did not differ between patients undergoing IPAA and those undergoing IRA(p= 0.73, 4.1% versus 1.9% at 10 years). The cumulative 5-year overall survival rate after additional surgery for the tumor of RCRS was 82%. CONCLUSION: This study has several limitations due to single institutional retrospective study with small cases and non-standardized postoperative endoscopic surveillance. However, our results seem to show satisfactory oncological outcomes of patients with FAP in terms of the control of cancer of the RCRS under postoperative periodic surveillance, regardless of the type of colorectal resection.
Subject(s)
Adenomatous Polyposis Coli , Neoplasms , Humans , Male , Female , Adolescent , Young Adult , Adult , Middle Aged , Aged , Retrospective Studies , Ileum/surgery , Adenomatous Polyposis Coli/surgery , Anastomosis, Surgical/adverse effectsABSTRACT
Several bacterial strains, including probiotic strains, have undergone evaluations for their safety and potential beneficial health effects. Some of these strains have been introduced into various markets, including that for infant products. However, certain probiotic strains have been linked to serious infections in infants, such as septicemia and meningitis. Given this, it is crucial to assess the safety of each probiotic strain, including those of Bifidobacterium, which is a common genus of probiotics. One such strain, Bifidobacterium bifidum OLB6378 (NITE BP-31), referred to as OLB6378 hereafter, has been selected for use in infants. To determine its genotoxicity and general toxicity potential, a heat-treated OLB6378 concentrate was subjected to various tests, including the bacterial reverse mutation test, in vitro chromosome aberration test, in vivo micronucleus test, and single- and 90-day oral gavage toxicity studies in rats. No significant differences were observed compared with negative controls in any of genotoxicity tests. The single-dose toxicity study employed dose levels of 560, 1,693, and 5,092â mg/kg, representing the total solid contents of culture concentrates containing OLB6378 (equivalent to 8.1 × 1011, 2.4 × 1012, and 7.4 × 1012 cells/kg of Bifidobacterium, respectively). In the 90-day toxicity study, dose levels of 280, 853, and 2,546â mg/kg/day were used (equivalent to 4.0 × 1011, 1.2 × 1012, and 3.7 × 1012 cells/kg/day, respectively). Importantly, the heat-treated OLB6378 concentrate did not induce any signs of toxicity in any of the conducted toxicity studies. In conclusion, the heat-treated OLB6378 concentrate exhibited no genotoxicity potential, and the no-observed-adverse-effect level in the 90-day toxicity study was determined to be 2,546â mg/kg/day (equivalent to 3.7 × 1012 cells/kg/day). This suggests that heat-treated OLB6378 can be safely utilized as a food source.
ABSTRACT
The capsid of human immunodeficiency virus type 1 (HIV-1) forms a conical structure by assembling oligomers of capsid (CA) proteins and is a virion shell that encapsulates viral RNA. The inhibition of the CA function could be an appropriate target for suppression of HIV-1 replication because the CA proteins are highly conserved among many strains of HIV-1, and the drug targeting CA, lenacapavir, has been clinically developed by Gilead Sciences, Inc. Interface hydrophobic interactions between two CA molecules via the Trp184 and Met185 residues in the CA sequence are indispensable for conformational stabilization of the CA multimer. Our continuous studies found two types of small molecules with different scaffolds, MKN-1 and MKN-3, designed by in silico screening as a dipeptide mimic of Trp184 and Met185 have significant anti-HIV-1 activity. In the present study, MKN-1 derivatives have been designed and synthesized. Their structure-activity relationship studies found some compounds having potent anti-HIV activity. The present results should be useful in the design of novel CA-targeting molecules with anti-HIV activity.
Subject(s)
Anti-HIV Agents , HIV-1 , Humans , Capsid Proteins/chemistry , Capsid Proteins/genetics , Capsid Proteins/metabolism , Virus Assembly , Capsid/metabolism , Anti-HIV Agents/pharmacology , Anti-HIV Agents/chemistry , Anti-HIV Agents/metabolismABSTRACT
Six aromatic secondary metabolites, pestalone (1), emodin (2), phomopsilactone (3), pestalachlorides B (4), C (5), and D (6), were isolated from Pestalotiopsis sp. FKR-0115, a filamentous fungus collected from white moulds growing on dead branches in Minami Daito Island. The efficacy of these secondary metabolites against methicillin-resistant Staphylococcus aureus (MRSA) with and without meropenem (ß-lactam antibiotic) was evaluated using the paper disc method and broth microdilution method. The chemical structures of the isolated compounds (1-6) were characterised using spectroscopic methods, including nuclear magnetic resonance and mass spectrometry. All six isolated compounds exhibited synergistic activity with meropenem against MRSA. Among the six secondary metabolites, pestalone (1) overcame bacterial resistance in MRSA to the greatest extent.
Subject(s)
Benzophenones , Methicillin-Resistant Staphylococcus aureus , Methicillin-Resistant Staphylococcus aureus/metabolism , Anti-Bacterial Agents/pharmacology , Meropenem/metabolism , Meropenem/pharmacology , Pestalotiopsis , beta-Lactams/pharmacology , beta-Lactams/metabolism , beta-Lactam Resistance , Microbial Sensitivity TestsABSTRACT
In the development of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) drugs, its main protease (Mpro), which is an essential enzyme for viral replication, is a promising target. To date, the Mpro inhibitors, nirmatrelvir and ensitrelvir, have been clinically developed by Pfizer Inc. and Shionogi & Co., Ltd., respectively, as orally administrable drugs to treat coronavirus disease of 2019 (COVID-19). We have also developed several potent inhibitors of SARS-CoV-2 Mpro that include compounds 4, 5, TKB245 (6), and TKB248 (7), which possesses a 4-fluorobenzothiazole ketone moiety as a reactive warhead. In compounds 5 and TKB248 (7) we have also found that replacement of the P1-P2 amide of compounds 4 and TKB245 (6) with the corresponding thioamide improved their pharmacokinetics (PK) profile in mice. Here, we report the design, synthesis and evaluation of SARS-CoV-2 Mpro inhibitors with replacement of a digestible amide bond by surrogates (9-11, 33, and 34) and introduction of fluorine atoms in a metabolically reactive methyl group on the indole moiety (8). As the results, these compounds showed comparable or less potency compared to the corresponding parent compounds, YH-53/5h (2) and 4. These results should provide useful information for further development of Mpro inhibitors.
Subject(s)
COVID-19 , Animals , Mice , SARS-CoV-2 , Amides/pharmacology , Halogens , Protease Inhibitors/chemistry , Viral Nonstructural Proteins , Antiviral Agents/chemistryABSTRACT
Solid pseudopapillary tumor (SPT) is a low-grade malignant tumor of the pancreas. SPT typically affects women and can occur in ectopic pancreatic region; however, it also occurs rarely in retroperitoneum. The tumor may be bulky at the time of diagnosis since there is no specific clinical manifestation. Here we present an older male case with retroperitoneal SPT. A 67-year-old man consulted for intermittent fever and lumbago. His basal hormonal profile screened out a functional tumor. Computed tomography (CT) showed a gigantic mass in his left adrenal region. A normal left adrenal gland was not identified, and the tumor's feeding artery was recognized as the left adrenal artery by the contrast-enhanced CT. Adrenal malignant tumor was suspected, and tumor resection was performed. The resected tumor size was 15 × 10 × 9â cm. Histologically, epithelial-like cells with round nuclei and a small amount of eosinophilic cytoplasm proliferated in papillary (around the blood vessels) or uniformly solid form. By immunostaining, tumor cells were vimentin, CD56, cytokeratin AE1/AE3, CD10, ß-catenin in the nucleus, cyclin D1, and PgR positive. These findings led to the diagnosis of SPT. Although rare, SPT should be considered as a differential diagnosis in cases of a mass arising from the adrenal region.
ABSTRACT
Immune checkpoint inhibitors(ICIs)are widely used for the treatment of unresectable gastric cancer. We treated approximately 70 patients with ICIs. ICI treatment with pembrolizumab was administered for MSI-high cases and nivolumab for MSS cases in the second- or third-line chemotherapy. We observed 5 cases of complete response. Among these, 2 patients presented with liver metastases, 2 with peritoneal disseminations, and 1 with pulmonary metastasis. In 1 patient, the primary tumor invaded the diaphragm and descending aorta; whereas, in another patient the primary tumor invaded the pancreas and liver. All patients had progressive disease after first-line chemotherapy.
Subject(s)
Immune Checkpoint Inhibitors , Stomach Neoplasms , Humans , Stomach Neoplasms/drug therapy , Nivolumab/therapeutic use , Diaphragm , LiverABSTRACT
Hepatitis B is a viral hepatitis, which is caused by infection of hepatitis B virus (HBV). This disease progresses to chronic hepatitis, cirrhosis and liver cancer. To treat hepatitis B, exclusion of virus and covalently closed circular DNA (cccDNA) that is formed in hepatocyte nucleus is necessary. A hepatitis B capsid protein (HBc) is an indispensable protein, which forms the capsid that encapsulates viral DNA. Since HBc is correlated to the transcriptional regulation of cccDNA, this protein would be an attractive target for complete cure of hepatitis B. By in silico screening of a library of compounds, a small compound, Cpd4 (1), which binds to a hydrophobic cavity located in the inner pocket on the tetramer interface of HBc proteins, was identified. In anti-HBV assays, this synthetic compound, Cpd4 (1) decreased the amount of HBV core related antigen (HBcrAg), which has been correlated with the proliferation of HBV, and decreased the amount of HBV surface antigen (HBsAg), which is correlated with the amount of cccDNA. Based on Cpd4 (1) as a lead compound, 20 derivatives of 1 were designed and synthesized and their structure-activity relationships were examined. As a result, specific interactions between each compound and amino acid residues of the target protein appeared to be unimportant but the shape/size of compounds which can bind to the hydrophobic cavity might be important in the expression of high anti-HBV activity, and a more potent derivative, TKB-HBV-CA-001 (3b), was discovered. These results will be useful in the development of novel anti-HBV agents for a complete cure of hepatitis B.
ABSTRACT
The filamentous fungus Synnemellisia sp. strain FKR-0921 was obtained from soil collected on Kume Island, Okinawa. The MeOH extract of FKR-0921 cultured on a solid rice medium yielded a new aromatic compound, synnemellisitriol A (1). The structure, including the absolute configuration, was elucidated by spectroscopic analysis (FT-IR, NMR, and HR-ESI-MS), and the absolute configuration at C-9 of 1 was determined using the modified Mosher's method. Additionally, 1 was evaluated for its biological activities, including metallo-ß-lactamase inhibitory activity, type III secretion system inhibitory activity, antimicrobial activity, antimalarial activity, and cytotoxicity.
Subject(s)
Hypocreales , Phenols , Hypocreales/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Spectroscopy, Fourier Transform Infrared , Phenols/chemistry , Phenols/pharmacology , beta-Lactamase Inhibitors/chemistry , beta-Lactamase Inhibitors/pharmacology , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacologyABSTRACT
The main protease (Mpro) of SARS-CoV-2 is an attractive target for the development of drugs to treat COVID-19. Here, we report the design, synthesis, and structure-activity relationship (SAR) studies of highly potent SARS-CoV-2 Mpro inhibitors including TKB245 (5)/TKB248 (6). Since we have previously developed Mpro inhibitors (3) and (4), several hybrid molecules of these previous compounds combined with nirmatrelvir (1) were designed and synthesized. Compounds such as TKB245 (5) and TKB248 (6), containing a 4-fluorobenzothiazole moiety at the P1' site, are highly effective in the blockade of SARS-CoV-2 replication in VeroE6 cells. Replacement of the P1-P2 amide with the thioamide surrogate in TKB248 (6) improved its PK profile in mice compared to that of TKB245 (5). A new diversity-oriented synthetic route to TKB245 (5) derivatives was also developed. The results of the SAR studies suggest that TKB245 (5) and TKB248 (6) are useful lead compounds for the further development of Mpro inhibitors.
ABSTRACT
The marine red algal genus Laurencia has abundant halogenated secondary metabolites, which exhibit novel structural types and possess various unique biological potentials, including antifouling activity. In this study, we report the isolation, structure elucidation, and antifouling activities of two novel brominated diterpenoids, aplysin-20 aldehyde (1), 13-dehydroxyisoaplysin-20 (2), and its congeners. We screened marine red alga Laurencia venusta Yamada for their antifouling activity against the mussel Mytilus galloprovincialis. Ethyl acetate extracts of L. venusta from Hiroshima and Chiba, Japan, were isolated and purified, and the compound structures were identified using 1D and 2D NMR, HR-APCI-MS, IR, and chemical synthesis. Seven secondary metabolites were identified, and their antifouling activities were evaluated. Compounds 1, 2, and aplysin-20 (3) exhibited strong activities against M. galloprovincialis. Therefore, these compounds can be explored as natural antifouling drugs.
Subject(s)
Biofouling , Diterpenes , Laurencia , Rhodophyta , Biofouling/prevention & control , Diterpenes/pharmacology , Diterpenes/chemistry , Laurencia/chemistry , Molecular Structure , Rhodophyta/chemistryABSTRACT
A new irieane-type diterpene, 12-hydroxypinnaterpene C (1), and 21 known compounds, angasiol acetate (2), angasiol (3), 11-deacetylpinnaterpene C (4), palisadin A (5), 12-acetoxypalisadin B (6), 12-hydroxypalisadin B (7), aplysistatin (8), luzodiol (9), 5-acetoxy-2-bromo-3-chloro-chamigra-7(14),9-dien-8-one (10), neoirietriol (11), neoirietetraol (12), (3Z)-laurenyne (13), cupalaurenol (14), cupalaurenol acetate (15), (3Z)-venustinene (16), 10-hydroxykahukuene B (17), aplysiol B (18), (3Z)-13-epipinnatifidenyne (19), 3Z,6R,7R,12S,13S-obtusenyne (20), (3Z,9Z)-7-chloro-6-hydroxy-12-oxo-pentadeca-3,9-dien-1-yne (21), and cholest-7-en-3,5,7-triol (22) were isolated from the digestive diverticula of Aplysia argus from the Ikei Island in Okinawa, Japan. The structures of these compounds were determined using spectroscopic methods such as NMR and HR-ESI-MS. These compounds were tested for their antibacterial activity against the phytopathogen Ralstonia solanacearum. Compounds 11 and 21 exhibited antibacterial activity at 30â µg/disc. In this study, we also discuss the types of red algae that A. argus feeds on in the shallow waters of Okinawa Prefecture.
Subject(s)
Aplysia , Rhodophyta , Animals , Anti-Bacterial Agents/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Rhodophyta/chemistry , DiterpenesABSTRACT
Cells latently infected with human immunodeficiency virus type 1 (HIV-1) prevent people living with HIV-1 from obtaining a cure to the infectious disease. Latency reversing agents (LRAs) such as protein kinase C (PKC) activators and histone deacetylase (HDAC) inhibitors can reactivate cells latently infected with HIV-1. Several trials based on treatment with HDAC inhibitors alone, however, failed to reduce the number of latent HIV-1 reservoirs. Herein, we have focused on a diacylglycerol (DAG)-lactone derivative, YSE028 (1), which is a PKC activator with latency reversing activity and no significant cytotoxicity. Caspase-3 activation of YSE028 (1) led to cell apoptosis, specifically in HIV-1 latently infected cells. Structure-activity relationship studies of YSE028 (1) have produced several useful derivatives. Among these, compound 2 is approximately ten times more potent than YSE028 (1) in reactivation of cells latently infected with HIV-1. The activity of DAG-lactone derivatives was correlated with the binding affinity for PKC and the stability against esterase-mediated hydrolysis.
Subject(s)
HIV Infections , HIV-1 , Humans , CD4-Positive T-Lymphocytes/metabolism , Diglycerides , Histone Deacetylase Inhibitors/pharmacology , HIV-1/metabolism , Protein Kinase C , Virus Activation , Virus LatencyABSTRACT
Two new eremophilane-type sesquiterpenoids, fusumaols A (1) and B (2), were isolated from the stem-leafy liverwort, Bazzania japonica collected in Mori-Machi, Shizuoka, Japan. Their structures were established using extensive spectroscopic (IR, MS, and 2D NMR) data, and the absolute configuration of 1 was determined by the modified Mosher's method. This is the first time eremophilanes have been discovered in the liverwort genus Bazzania. Compounds 1 and 2 were evaluated for their repellent activity against the adult population of the rice weevil Sitophilus zeamais using the modified filter paper impregnation method. Both sesquiterpenoids showed moderate repellent activities.