313 results on '"Takashi Kamada"'
Search Results
2. New acetogenin katsuurallene from Laurencia saitoi collected from Katsuura, Japan
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Yu Minamida, Hiroshi Matsuura, Takahiro Ishii, Miyu Miyagi, Yuto Shinjo, Kosuke Sato, Takashi Kamada, Yoshihiro Mihara, Iwao Togashi, Keisuke Sugimoto, Tsuyoshi Abe, Norio Kikuchi, and Minoru Suzuki
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Laurencia ,Rhodomelaceae ,Acetogenin ,Triterpene ,Diterpene ,Biological activity ,Botany ,QK1-989 - Abstract
Abstract We examined the chemical constitution of the red alga Laurencia saitoi Perestenko, collected from Katsuura, Boso Peninsula, Chiba Prefecture, Japan. This specimen produced a new polyhalogenated acetogenin, named katsuurallene (1), which structure was determined by the spectral methods, along with known diterpene, deoxyparguerol (2) and triterpene, thyrsiferol (3). In this paper we describe the structural elucidation of katsuurallene together with some biological activities.
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- 2022
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3. A New Epi-neoverrucosane-type Diterpenoid from the Liverwort Pleurozia subinflata in Borneo
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Takashi Kamada, Mary Lyn Johanis, Shean-Yeaw Ng, Chin-Soon Phan, Monica Suleiman, and Charles S. Vairappan
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Epi-neoverrucosane ,Diterpenoid ,Pleurozia subinflata ,Liverwort ,Borneo ,Botany ,QK1-989 - Abstract
Abstract New bioactive 13-epi-neoverrucosane diterpenoid, 5β-acetoxy-13-epi-neoverrucosanic acid (1) along with three known secondary metabolites, 13-epi-neoverrucosan-5β-ol (2), chelodane (3) and (E)-β-farnesene (4) were isolated from the MeOH extract of east Malaysia’s liverwort Pleurozia subinflata. The chemical structure of new compound was elucidated by the analyses of its spectroscopic data (FTIR, NMR and HR-ESI-MS). These epi-neoverrucosane-type compounds seem to be notable chemosystematic markers for P. subinflata in Borneo. Compound 3 was widespread in marine sponges however this is the first record for 3 to be found in liverwort. These metabolites were tested for their antifungal potentials against selected fungi from the marine environment. Compound 1 exhibited effective antifungal activity against Lagenidium thermophilum. Graphic Abstract
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- 2020
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4. Plasma amino acids in patients with essential tremor
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Shiroh Miura, Takashi Kamada, Ryuta Fujioka, and Yoshihiro Yamanishi
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amino acid ,aspartic acid ,essential tremor ,glutamic acid ,taurine ,Medicine ,Medicine (General) ,R5-920 - Abstract
Abstract Essential tremor (ET) is one of the most common movement disorders. However, there are currently no accepted biomarkers for ET. This report suggested that concentration of plasma glutamic acid, aspartic acid, and taurine could be biomarkers for ET.
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- 2021
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5. Reversible Conduction Failure in Anti-lactosylceramide-antibody-positive Combined Central and Peripheral Demyelination
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Masaya Harada, Shiroh Miura, Hiroshi Kida, Taiga Moritaka, Ken-ichi Irie, Takashi Kamada, Yusuke Uchiyama, Sayuri Shima, Tatsuro Mutoh, Tomoaki Hoshino, and Takayuki Taniwaki
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combined central and peripheral demyelination (CCPD) ,encephalomyeloradiculoneuropathy (EMRN) ,lactosylceramide ,reversible conduction failure (RCF) ,total plasma exchange ,steroid ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
We describe a 60-year-old woman with combined central and peripheral demyelination who presented with obstinate constipation, weakness in the lower limbs, and a bilateral sensory disturbance below her chest followed by girdle sensation in the right region of the abdomen, which was responsive to steroid therapy and plasmapheresis. Serum anti-lactosylceramide antibody was positive without anti-neurofascin 155 antibody or anti-galactocerebroside antibody positivity. Two months later, the patient had a first relapse that was responsive to steroid treatment. A nerve conduction study confirmed reversible conduction failure (RCF) in both episodes. Our case is unique in that she had an RCF episode as well as some similarities to encephalomyeloradiculoneuropathy.
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- 2019
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6. Terpenoids from Marine Soft Coral of the Genus Xenia in 1977 to 2019
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Shean-Yeaw Ng, Chin-Soon Phan, Takahiro Ishii, Takashi Kamada, Toshiyuki Hamada, and Charles Santhanaraju Vairappan
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marine soft corals ,Xenia sp. ,natural products ,terpenes ,bioactivity ,Organic chemistry ,QD241-441 - Abstract
Members of the marine soft coral genus Xenia are rich in a diversity of diterpenes. A total of 199 terpenes consisting of 14 sesquiterpenes, 180 diterpenes, and 5 steroids have been reported to date. Xenicane diterpenes were reported to be the most common chemical skeleton biosynthesized by members of this genus. Most of the literature reported the chemical diversity of Xenia collected from the coral reefs in the South China Sea and the coastal waters of Taiwan. Although there was a brief review on the terpenoids of Xenia in 2015, the present review is a comprehensive overview of the structural diversity of secondary metabolites isolated from soft coral genus Xenia and their potent biological activity as reported between 1977 to 2019.
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- 2020
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7. A New Bromoallene-Producing Chemical Type of the Red Alga Laurencia nangii Masuda
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Charles Santhanaraju Vairappan and Takashi Kamada
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Laurencia nangii ,C15-acetogenin ,bromoallene ,chemical race ,Organic chemistry ,QD241-441 - Abstract
Six populations of Laurencia nangii were found to produce three bromoallenes; dihydroitomanallene B (1), itomanallene B (2) and pannosallene (3). Prior to this report, L. nangii were only known to produce C15-acetogenins with acetylene functionality. This could be regarded as a new chemical race of L. nangii. The compound structures were elucidated on the basis of spectroscopic analysis and comparison with those previously reported in literature. Compound 1, dihydroitomanallene B, was isolated as a new compound representing a minor variation of itomanallene B (2).
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- 2012
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8. Bioactive Cembranoids from the Soft Coral Genus Sinularia sp. in Borneo
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Takashi Kamada, Min-Cheol Kang, Chin-Soon Phan, Intan Irna Zanil, You-Jin Jeon, and Charles S. Vairappan
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cembrane ,terpenoid ,soft coral ,Sinularia ,anti-inflammation ,apoptosis ,structure-activity relationship ,Biology (General) ,QH301-705.5 - Abstract
Soft corals are known to be prolific producers of a wide spectrum of biologically active cembranoids. One new cembranoid, sinularolide F (2), along with three known compounds, cembranolide (1), (E,E,E)-6,10,14-trimethyl-3-methylene-cis-3α,4,5,8,9,12,13,15α-octahydrocyclo tetradeca[β]furan-2(3H)-one (3), and denticulatolide (4), were isolated from the Bornean soft coral Sinularia sp. Compounds 2 and 4 showed potential anti-inflammatory activities against lipopolysaccharide-stimulated RAW 264.7 with IC50 values less than 6.25 µg/mL and anticancer activity against HL60 cell lines. The compounds’ mechanisms of action were investigated via the Western blot evaluation of their protein markers. These activities could be attributed to the presence of tertiary methyl at C-8 and the compounds’ 3D configurations.
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- 2018
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9. New Marine Antifouling Compounds from the Red Alga Laurencia sp.
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Yuko Oguri, Mami Watanabe, Takafumi Ishikawa, Takashi Kamada, Charles S. Vairappan, Hiroshi Matsuura, Kensuke Kaneko, Takahiro Ishii, Minoru Suzuki, Erina Yoshimura, Yasuyuki Nogata, and Tatsufumi Okino
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antifouling ,biofouling ,barnacle ,terpenoid ,acetogenin ,Laurencia ,Rhodophyta ,Biology (General) ,QH301-705.5 - Abstract
Six new compounds, omaezol, intricatriol, hachijojimallenes A and B, debromoaplysinal, and 11,12-dihydro-3-hydroxyretinol have been isolated from four collections of Laurencia sp. These structures were determined by MS and NMR analyses. Their antifouling activities were evaluated together with eight previously known compounds isolated from the same samples. In particular, omaezol and hachijojimallene A showed potent activities (EC50 = 0.15–0.23 µg/mL) against larvae of the barnacle Amphibalanus amphitrite.
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- 2017
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10. Impact of <scp>COVID</scp> ‐19 pandemic on epilepsy care in Japan: A national‐level multicenter retrospective cohort study
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Naoto, Kuroda, Takafumi, Kubota, Toru, Horinouchi, Naoki, Ikegaya, Yu, Kitazawa, Satoshi, Kodama, Izumi, Kuramochi, Teppei, Matsubara, Naoto, Nagino, Shuichiro, Neshige, Temma, Soga, Yutaro, Takayama, Daichi, Sone, Kousuke, Kanemoto, Akio, Ikeda, Kiyohito, Terada, Hiroko, Goji, Shinji, Ohara, Koichi, Hagiwara, Takashi, Kamada, Koji, Iida, Nobutsune, Ishikawa, Hideaki, Shiraishi, Osato, Iwata, Hidenori, Sugano, Yasushi, Iimura, Takuichiro, Higashi, Hiroshi, Hosoyama, Ryosuke, Hanaya, Akihiro, Shimotake, Takayuki, Kikuchi, Takeshi, Yoshida, Hiroshi, Shigeto, Jun, Yokoyama, Takahiko, Mukaino, Masaaki, Kato, Masanori, Sekimoto, Masahiro, Mizobuchi, Yoko, Aburakawa, Masaki, Iwasaki, Eiji, Nakagawa, Tomohiro, Iwata, Kentaro, Tokumoto, Takuji, Nishida, Yukitoshi, Takahashi, Kenjiro, Kikuchi, Ryuki, Matsuura, Shin-Ichiro, Hamano, Ayataka, Fujimoto, Hideo, Enoki, Kyoichi, Tomoto, Masako, Watanabe, Youji, Takubo, Toshihiko, Fukuchi, Hidetoshi, Nakamoto, Yuichi, Kubota, Naoto, Kunii, Yuichiro, Shirota, Eiichi, Ishikawa, Nobukazu, Nakasato, Taketoshi, Maehara, Motoki, Inaji, Shunsuke, Takagi, Takashi, Enokizono, Yosuke, Masuda, and Takahiro, Hayashi
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Neurology ,Neurology (clinical) - Abstract
The impact of the coronavirus disease 2019 (COVID-19) pandemic on epilepsy care across Japan was investigated by conducting a multicenter retrospective cohort study.This study included monthly data on the frequency of (1) visits by outpatients with epilepsy, (2) outpatient electroencephalography (EEG) studies, (3) telemedicine for epilepsy, (4) admissions for epilepsy, (5) EEG monitoring, and (6) epilepsy surgery in epilepsy centers and clinics across Japan between January 2019 and December 2020. We defined the primary outcome as epilepsy-center-specific monthly data divided by the 12-month average in 2019 for each facility. We determined whether the COVID-19 pandemic-related factors (such as year [2019 or 2020], COVID-19 cases in each prefecture in the previous month, and the state of emergency) were independently associated with these outcomes.In 2020, the frequency of outpatient EEG studies (-10.7%, p0.001) and cases with telemedicine (+2,608%, p=0.031) were affected. The number of COVID-19 cases was an independent associated factor for epilepsy admission (-3.75*10We demonstrated the significant impact that the COVID-19 pandemic had on epilepsy care. These results support those of previous studies and clarify the effect size of each pandemic-related factor on epilepsy care.
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- 2022
11. Two New Abietane Diterpenoids from Plectranthus barbatus
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Takahiro Ishii, Natsuki Matayoshi, Kanako Taba, and Takashi Kamada
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Plant Science ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Published
- 2022
12. Front Cover: Two New Eremophilane‐Type Sesquiterpenoids from Japanese Liverwort Bazzania japonica (Chem. Biodiversity 4/2023)
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Ryosuke Fukada, Jin Kawano, Tomoki Tsuruta, Takuto Nonaka, Kosuke Sato, Susumu Miyajima, Shinnosuke Ishigami, Takahiro Ishii, Keisuke Nishikawa, Yoshinori Asakawa, and Takashi Kamada
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Molecular Medicine ,Bioengineering ,General Chemistry ,General Medicine ,Molecular Biology ,Biochemistry - Published
- 2023
13. Structural Diversity, Anti-Fungal Activity and Chemosystematics of Bornean Liverwort Bazzania harpago (De Not.) Schiffner
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Monica Suleiman, Lee-Ping Ang, Vui-Lun Hau, Charles Santhanaraju Vairappan, Shean Yeaw Ng, and Takashi Kamada
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Multidisciplinary ,Anthoceros ,biology ,biology.organism_classification ,Terpene ,chemistry.chemical_compound ,Harpago ,chemistry ,Sister group ,Genus ,Botany ,Caffeic acid ,Marchantiophyta ,Bazzania - Abstract
Two terpenes; cneorubin X (1), (-)-gymnomitr-3(15)-en-4β-ol (2) as well as one benzoic compound; caffeic acid (3) were isolated from Bazzania harpago collected from Mt. Trus Madi, Sabah, Malaysia. The structures of these secondary metabolites were elucidated based on spectroscopic data (Infra-Red (IR), 1D and 2D Nuclear Magnetic Resonance (NMR), and Mass Spectrum (MS)). This is the first record that cneorubin X (1) was isolated from non-vascular plants and it exhibited active anti-fungal activity against Haliphthoros sabahensis and Haliphthoros milfordensis. Chemosystematics finding suggests that the Marchantiophyta (liverworts) genus Bazzania might have a closer chemical relationship to its sister group Bryophyta (mosses) genus Brachythecium, Kindbergia and Mnium, as well as Anthocerophyta (hornworts) genus Anthocerosin their evolutionary history.
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- 2021
14. Stereo-electroencephalography evidence of an eccentrically located seizure-onset zone around a polymorphous low-grade neuroepithelial tumor of the young: illustrative case
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Koichi, Hagiwara, Takashi, Kamada, Satoshi O, Suzuki, Ayako, Miyoshi, Hideaki, Tanaka, Hiroshi, Shigeto, Shinji, Ohara, and Naoki, Akamatsu
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General Medicine - Abstract
BACKGROUND Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a newly identified low-grade brain tumor with frequent epileptic presentation. Despite the facilitated use of invasive electroencephalography owing to the growing availability of stereo-electroencephalography (SEEG), intracranial features of tumor-related seizures are still scarcely described. This report provides the first description of SEEG-recorded seizures in PLNTY to provide an insight into its surgical strategy. OBSERVATIONS Spontaneous clinical seizures were recorded with SEEG in a young adult patient with drug-resistant epilepsy associated with a PLNTY in the left lateral temporal cortex. The seizure onset was characterized by low-voltage fast activity (LVFA) and showed eccentric localization with respect to the tumor: LVFA was localized in the anterior portion of the tumor and spread toward the adjacent polar cortex. The language risks associated with the resection of the posterior temporal cortex could thus be minimized. LESSONS PLNTY can show a focal and eccentric seizure-onset zone around the tumor. The present findings serve to improve the functional and seizure outcomes using the staged invasive approach in PLNTY.
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- 2022
15. Postoperative striatal degeneration: a hitherto unrecognized impact of frontal disconnection surgery for drug-resistant epilepsy. Illustrative cases
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Koichi, Hagiwara, Hideaki, Tanaka, Ayako, Miyoshi, Takashi, Kamada, Hiroshi, Shigeto, Shinji, Ohara, and Naoki, Akamatsu
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General Medicine - Abstract
BACKGROUND Frontal disconnection surgery is a useful surgical option for patients with frontal epilepsy whose seizure onset zones are exceedingly large and thus are not amenable to conventional resective surgery. While it has the advantage of avoiding sequelae stemming from a large resection cavity, the impact of radical anatomofunctional disconnection of such a vast frontal region is not fully understood. OBSERVATIONS The authors have identified secondary degeneration in the striatum ipsilateral to the frontal disconnection surgery in two adult patients who had otherwise favorable postoperative outcomes following the surgery. On serial postoperative magnetic resonance imaging, the striatum showed transient restricted diffusion in the caudate head and rostral putamen around several weeks postoperatively and subsequent atrophy in the caudate head. The affected striatal regions (i.e., the anterior portion of the striatum) were congruent with the known fronto-striatal connectivity corresponding to the disconnected frontal regions anterior to the primary and supplementary motor areas. Both patients achieved 1-year seizure freedom without apparent disability related to the surgery. LESSONS The benign postoperative course despite the marked degenerative changes in the ipsilateral striatum supports the feasibility of the frontal disconnection surgery in otherwise inoperable patients with broad frontal epileptogenicity.
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- 2022
16. Corrigendum: Two New Halogenated Compounds from the Marine Red Alga Laurencia nipponica Yamada from the Kunashiri and Etorofu Islands
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Kosuke Sato, Kensuke Kaneko, Tsuyoshi Kamekawa, Kanako Taba, Shinnosuke Ishigami, Masahiro Wada, Takahiro Ishii, Tsuyoshi Abe, Takashi Kamada, and Minoru Suzuki
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Molecular Medicine ,Bioengineering ,General Chemistry ,General Medicine ,Molecular Biology ,Biochemistry - Published
- 2022
17. A New Epi-neoverrucosane-type Diterpenoid from the Liverwort Pleurozia subinflata in Borneo
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Shean Yeaw Ng, Mary Lyn Johanis, Charles Santhanaraju Vairappan, Monica Suleiman, Takashi Kamada, and Chin-Soon Phan
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Antifungal ,Marine sponges ,Liverwort ,medicine.drug_class ,Stereochemistry ,Chemical structure ,Plant Science ,Toxicology ,01 natural sciences ,Biochemistry ,Analytical Chemistry ,Epi-neoverrucosane ,Type (biology) ,Diterpenoid ,Borneo ,lcsh:Botany ,medicine ,Bioorganic chemistry ,Lagenidium thermophilum ,Pharmacology ,Pleurozia ,biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,biology.organism_classification ,Terpenoid ,0104 chemical sciences ,lcsh:QK1-989 ,010404 medicinal & biomolecular chemistry ,Original Article ,Pleurozia subinflata ,Food Science - Abstract
Abstract New bioactive 13-epi-neoverrucosane diterpenoid, 5β-acetoxy-13-epi-neoverrucosanic acid (1) along with three known secondary metabolites, 13-epi-neoverrucosan-5β-ol (2), chelodane (3) and (E)-β-farnesene (4) were isolated from the MeOH extract of east Malaysia’s liverwort Pleurozia subinflata. The chemical structure of new compound was elucidated by the analyses of its spectroscopic data (FTIR, NMR and HR-ESI-MS). These epi-neoverrucosane-type compounds seem to be notable chemosystematic markers for P. subinflata in Borneo. Compound 3 was widespread in marine sponges however this is the first record for 3 to be found in liverwort. These metabolites were tested for their antifungal potentials against selected fungi from the marine environment. Compound 1 exhibited effective antifungal activity against Lagenidium thermophilum. Graphic Abstract
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- 2020
18. New Marine Diterpenoid from the Okinawan Soft Coral, Lobophytum sp
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Kosuke Sato, Shinnosuke Ishigami, Masaki Koike, Haruto Takegahara, Ayumi Yamamoto, Kensuke Kaneko, Kazuki Tani, Takahiro Ishii, and Takashi Kamada
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Pharmacology ,Complementary and alternative medicine ,Drug Discovery ,Plant Science ,General Medicine - Abstract
A new lobane-type diterpenoid, loba-8,10,13(15)-triene-14,17,18-triol 17-acetate (1), and 5 known compounds, lobatriene (2), (17 R)-loba-8,10,13(15)-triene-17,18-diol (3), loba-8,10,13(15)-triene-14,17,18-triol 14,17-diacetate (4), loba-8,10,13(15)-triene-14,17,18-triol 14-acetate (5), and lobatrienetriol (6), were isolated from a population of Okinawan soft coral Lobophytum sp. The structures of these compounds were elucidated by spectroscopy, including nuclear magnetic resonance and high-resolution mass spectrometry. The cytotoxicity and genotoxicity of these compounds were tested using human lymphoblastoid TK6 cells.
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- 2023
19. Antifungal diterpene from Rhizome of wild bornean ginger, Hornstedtia havilandii (Zingiberaceae)
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Rolinus Paulous, Zuraini Zakaria, Julianah Awang, Takashi Kamada, and Charles S. Vairappan
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Biochemistry ,Ecology, Evolution, Behavior and Systematics - Published
- 2022
20. Risk factors for psychological distress in electroencephalography technicians during the COVID-19 pandemic: A national-level cross-sectional survey in Japan
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Naoto Kuroda, Takafumi Kubota, Toru Horinouchi, Naoki Ikegaya, Yu Kitazawa, Satoshi Kodama, Teppei Matsubara, Naoto Nagino, Shuichiro Neshige, Temma Soga, Daichi Sone, Yutaro Takayama, Izumi Kuramochi, Kousuke Kanemoto, Akio Ikeda, Kiyohito Terada, Hiroko Goji, Shinji Ohara, Koichi Hagiwara, Takashi Kamada, Koji Iida, Nobutsune Ishikawa, Hideaki Shiraishi, Osato Iwata, Hidenori Sugano, Yasushi Iimura, Takuichiro Higashi, Hiroshi Hosoyama, Ryosuke Hanaya, Akihiro Shimotake, Takayuki Kikuchi, Takeshi Yoshida, Hiroshi Shigeto, Jun Yokoyama, Takahiko Mukaino, Masaaki Kato, Masanori Sekimoto, Masahiro Mizobuchi, Yoko Aburakawa, Masaki Iwasaki, Eiji Nakagawa, Tomohiro Iwata, Kentaro Tokumoto, Takuji Nishida, Yukitoshi Takahashi, Kenjiro Kikuchi, Ryuki Matsuura, Shin-ichiro Hamano, Hideo Yamanouchi, Satsuki Watanabe, Ayataka Fujimoto, Hideo Enoki, Kyoichi Tomoto, Masako Watanabe, Youji Takubo, Toshihiko Fukuchi, Hidetoshi Nakamoto, Yuichi Kubota, Naoto Kunii, Yuichiro Shirota, Eiichi Ishikawa, Nobukazu Nakasato, Taketoshi Maehara, Motoki Inaji, Shunsuke Takagi, Takashi Enokizono, Yosuke Masuda, and Takahiro Hayashi
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Multivariate analysis ,Cross-sectional study ,clinical neurophysiology ,Psychological Distress ,Article ,stress ,Behavioral Neuroscience ,Epilepsy ,Japan ,Risk Factors ,Bayesian multivariate linear regression ,medicine ,Humans ,EEG ,Pandemics ,COVID-19, coronavirus disease 2019 ,Response rate (survey) ,business.industry ,SARS-CoV-2 ,technician ,COVID-19 ,Electroencephalography ,medicine.disease ,Mental health ,Distress ,Cross-Sectional Studies ,Neurology ,Respondent ,epilepsy ,Female ,Neurology (clinical) ,business ,EEG, electroencephalography ,PPE, personal protective equipment ,SARS-CoV-2, severe acute respiratory syndrome coronavirus-2 ,Stress, Psychological ,Clinical psychology - Abstract
OBJECTIVE To identify the risk factors for psychological distress in electroencephalography (EEG) technicians during the coronavirus disease 2019 (COVID-19) pandemic. METHOD In this national-level cross-sectional survey initiated by Japan Young Epilepsy Section (YES-Japan), which is a national chapter of The Young Epilepsy Section of the International League Against Epilepsy (ILAE-YES), a questionnaire was administered to 173 technicians engaged in EEG at four clinics specializing in epilepsy care and 20 hospitals accredited as (quasi-) epilepsy centers or epilepsy training facilities in Japan from March 1 to April 30, 2021. We collected data on participants' profiles, information about work, and psychological distress outcome measurements, such as the K-6 and Tokyo Metropolitan Distress Scale for Pandemic (TMDP). Linear regression analysis was used to identify the risk factors for psychological distress. Factors that were significantly associated with psychological distress in the univariate analysis were subjected to multivariate analysis. RESULTS Among the 142 respondents (response rate: 82%), 128 were included in the final analysis. As many as 35.2% of EEG technicians have been under psychological distress. In multivariate linear regression analysis for K-6, female sex, examination for patients (suspected) with COVID-19, and change in salary or bonus were independent associated factors for psychological distress. Contrastingly, in multivariate linear regression analysis for TMDP, female sex, presence of cohabitants who had to be separated from the respondent due to this pandemic, and change in salary or bonus were independent associated factors for psychological distress. CONCLUSION We successfully identified the risk factors associated with psychological distress in EEG technicians during the COVID-19 pandemic. Our results may help in understanding the psychological stress in EEG technicians during the COVID-19 pandemic and improving the work environment, which is necessary to maintain the mental health of EEG technicians.
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- 2021
21. Ictal asystole as a manifestation of pure insular epilepsy
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Shinji Ohara, Takashi Kamada, Naoki Akamatsu, Koichi Hagiwara, Hideaki Tanaka, Takahiko Mukaino, Toshiki Okadome, Taira Uehara, Ayako Miyoshi, and Hiroshi Shigeto
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Epilepsy ,business.industry ,Electroencephalography ,General Medicine ,medicine.disease ,Heart Arrest ,Neurology ,Anesthesia ,Medicine ,Humans ,Ictal ,Neurology (clinical) ,Asystole ,business - Published
- 2021
22. Two New Halogenated Compounds from the Marine Red Alga Laurencia nipponica Yamada from the Kunashiri and Etorofu Islands
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Tsuyoshi Abe, Shinnosuke Ishigami, Takahiro Ishii, Kanako Taba, Masahiro Wada, Tsuyoshi Kamekawa, Kensuke Kaneko, Takashi Kamada, Minoru Suzuki, and Kosuke Sato
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Islands ,Halogenation ,Warm current ,Chemistry ,Molecular Conformation ,Bioengineering ,General Chemistry ,General Medicine ,Biochemistry ,Laurencia ,Isolaurallene ,Japan ,Laurencia nipponica ,Botany ,Molecular Medicine ,Molecular Biology ,Sesquiterpenes - Abstract
The red alga Laurencia nipponica comprises various chemical races distributed relative to the ocean current in Japanese coastal areas. We investigated the chemical compositions and chemical races of L. nipponica distributed from the Kunashiri and Etorofu Islands, the confluence of the Soya warm current and Oya-shio cold current. Two new halogenated secondary metabolites, deacetylneonipponallene (1) and neopacifenol (2), along with four known compounds, deoxyprepacifenol (3), pacifenol (4), halo-chamigrene diether (5), and isolaurallene (6) were isolated from L. nipponica collected at Chikappunai, Kunashiri Island, while Zaimokuiwa (Kunashiri Island) and Sana (Etorofu Island) populations contained 3, 7-hydroxylaurene (7), 2,10-dibromo-3-chloro-9-hydroxy-α-chamigrene (8), and (3Z)-laurefucin (9). The structures of 1 and 2 were established using spectroscopic methods. The chemical races of L. nipponica distributed in this area were divided into 6- and 9-producing races. Interestingly, both races contained 4 as an additional race-index, as well as its derivatives, 2 and 5. To the best of our knowledge, this is the first example of a race comprising a mixture of two race-index compounds, suggesting that the convergence of two currents causes the production of new and diverse chemical races in this species.
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- 2021
23. Cytotoxicity and Antibacterial Potential of Halogenated Chamigrenes from Malaysian Red Alga, Laurencia majuscula
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Chin-Soon Phan, Tatsufumi Okino, Takashi Kamada, and Charles Santhanaraju Vairappan
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education.field_of_study ,biology ,Stereochemistry ,Metabolite ,Population ,Laurencia ,Red algae ,biology.organism_classification ,Rhodomelaceae ,HeLa ,chemistry.chemical_compound ,chemistry ,Cytotoxicity ,education ,Bacteria - Abstract
Red algae of the genus Laurencia have been known to produce a wide array of bioactive secondary metabolites. Here, we report the isolation of two new halogenated chamigrenes, lauremantanones A (1) and B (2), along with seven known compounds, dendroidiol (3), (+)-elatol (4), cartilagineol (5), obtusol (6), (+)-laurencenone B (7), 2-chloro-3-hydroxy-α-chamigren-9-one (8), and puertitol A (9), from a population of Laurencia majuscula (Harvey) Lucas from Mantanani Island (North Borneo). The structures of the two new metabolites were determined based on spectroscopic data (IR, 1D and 2D NMR, and MS). Compounds isolated from this alga exhibited potent cytotoxic (HeLa, MCF-7, P-388) and antibacterial (against antibiotic-resistant clinical bacteria) activities. The major metabolite of this population has significant importance in the geographical distribution of this species globally.
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- 2019
24. Sinulaflexiolide P, A Cembrane-Type Diterpenoid from Bornean Soft Coral Sinularia flexibilis
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Chin-Soon Phan, Chun-Sieng Yee, Takashi Kamada, Takahiro Ishii, and Charles Santhanaraju Vairappan
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education.field_of_study ,biology ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Coral ,Population ,Sinularia flexibilis ,Plant Science ,General Chemistry ,biology.organism_classification ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Terpenoid ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,education ,Marine fungi - Abstract
A new cembrane-type diterpenoid, sinulaflexiolide P (1), along with three known derivatives: sinulaflexiolide H (2), 11-epi-sinulariolide acetate (3), and (1S*,3S*,4S*,7E,11E)-3,4-epoxy-13-oxo-3,7,11,15-cembratriene (4), was isolated from a population of Bornean soft coral Sinularia flexibilis. The structures of these metabolites were elucidated based on spectroscopic data including NMR and HR-ESI-MS. In addition, these compounds were tested against six strains of marine fungi.
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- 2019
25. MIBG myocardial scintigraphy in progressive supranuclear palsy
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Yoshihiro Yamanishi, Takayuki Taniwaki, Hiroshi Kida, Shiroh Miura, Takashi Kamada, Tomoaki Hoshino, and Ken-ichi Irie
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Male ,medicine.medical_specialty ,Progressive supranuclear palsy ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,Myocardial scintigraphy ,Internal medicine ,Humans ,Medicine ,Washout rate ,030212 general & internal medicine ,Brainstem atrophy ,Aged ,Retrospective Studies ,Aged, 80 and over ,business.industry ,Parkinsonism ,Myocardial Perfusion Imaging ,Mediastinum ,Parkinson Disease ,Middle Aged ,Multiple System Atrophy ,medicine.disease ,Magnetic Resonance Imaging ,eye diseases ,Pons ,3-Iodobenzylguanidine ,medicine.anatomical_structure ,Neurology ,Cardiology ,Female ,Supranuclear Palsy, Progressive ,Neurology (clinical) ,Radiopharmaceuticals ,business ,030217 neurology & neurosurgery ,Brain Stem - Abstract
Background and objectives Meta-iodobenzylguanidine (MIBG) myocardial scintigraphy is an effective tool for distinguishing Parkinson's disease (PD) from other diseases accompanied by parkinsonism. Unlike other Parkinsonian diseases, in PD, MIBG accumulation in the heart tends to decrease. However, previous studies have reported that a decrease in MIBG accumulation also occurs in progressive supranuclear palsy (PSP). Thus, we analyzed the relationship between the degree of MIBG accumulation decrease, clinical symptoms, and brainstem atrophy in PSP. Methods We retrospectively collected data from patients who underwent MIBG myocardial scintigraphy and compared MIBG indices (heart to mediastinum [H/M] ratio, washout rate) between subjects with PSP and other diseases including PD. In addition, we evaluated the relationship between clinical characteristics, MIBG accumulation, and brainstem atrophy in patients with PSP. Results Patients with PSP had a significantly lower early H/M ratio compared with multiple system atrophy with predominant parkinsonism (MSA-P) patients, and a control group. In PSP patients there was a correlation between the decrease in delay H/M ratio, atrophy of the pons, and clinical severity as evaluated by Hoehn and Yahr score. Conclusion Unlike in PD, PSP patients exhibited a mild decrease in MIBG accumulation in MIBG myocardial scintigraphy, which may be related to brainstem atrophy.
- Published
- 2019
26. Familial paroxysmal kinesigenic dyskinesia with a novel missense variant (Arg2866Trp) in NBEA
- Author
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Yusuke Uchiyama, Shiroh Miura, Takuya Morikawa, Ryuta Fujioka, Tomofumi Shimojo, Hiroki Shibata, Takashi Kamada, and Seiji Kurata
- Subjects
0301 basic medicine ,Proband ,Adult ,medicine.medical_specialty ,Mutation, Missense ,Vesicular Transport Proteins ,Nerve Tissue Proteins ,030105 genetics & heredity ,Rats, Sprague-Dawley ,03 medical and health sciences ,Epilepsy ,Young Adult ,Internal medicine ,Exome Sequencing ,Genetics ,medicine ,Missense mutation ,Animals ,Humans ,Genetic Predisposition to Disease ,RNA, Messenger ,Genetics (clinical) ,business.industry ,Clinical course ,Paroxysmal dyskinesia ,Middle Aged ,Rat brain ,medicine.disease ,Pedigree ,Rats ,Dystonia ,030104 developmental biology ,Endocrinology ,Mrna level ,Female ,business ,Carrier Proteins ,Familial Paroxysmal Kinesigenic Dyskinesia - Abstract
Paroxysmal kinesigenic dyskinesia (PKD) is a movement disorder characterized by episodic involuntary movement attacks triggered by sudden movements, acceleration, or intention to move. We ascertained two Japanese familial cases with PKD. The proband is a 22-year-old woman who had noted sudden brief (30 s) of involuntary movements provoked by kinesigenic trigger such as starting to run, getting on a train, picking up a telephone receiver and so on at the age of 14. Interictal brain single photon emission computed tomography (SPECT) showed hyperperfusion in the left thalamus. A 46-year-old woman, the mother of the proband was also suffering from brief attacks triggered by starting to run in her high school days. On neurological examination, both showed no abnormality. Whole exome sequencing combined with rigorous filtering revealed two heterozygous nonsynonymous variants (NM_001447: c.8976GC [p.Gln2992His] in FAT2 and NM_015678: c.8596CT [p.Arg2866Trp] in NBEA). Real time quantitative PCR analysis of Nbea mRNA levels in the developing rat brain revealed peak at postnatal day 28 and decline at postnatal day 56. This result might match the most common clinical course of PKD from the point of view of the most common age at remission. NBEA has been reported to be responsible for neurodevelopmental disease accompanied by epilepsy. We concluded the variant in NBEA most likely to be responsible for our familial cases of PKD.
- Published
- 2020
27. Unusual Cembrane Diterpenoid Isolated from the Japanese Soft Coral Genus Sinularia
- Author
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Takashi Kamada, Takahiro Ishii, Kosuke Sato, Ginji Ito, Jin Kawano, Wakako Takabe, Chin-Soon Phan, and Shinnosuke Ishigami
- Subjects
Pharmacology ,Organic Chemistry ,Analytical Chemistry - Published
- 2022
28. New Bioactive Sesquiterpenoid from Malaysian Soft Coral Genus Lemnalia
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Charles S. Vairappan, Kazuki Tani, Takashi Kamada, and Chin-Soon Phan
- Subjects
Pharmacology ,Organic Chemistry ,Analytical Chemistry - Published
- 2022
29. Two new epimers of C15-acetogenin, 4-epi-isolaurallene and 4-epi-itomanallene A as diastereomeric model
- Author
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Phan, Chin Soon, Takashi Kamada, Charles S. Vairappan, Phan, Chin Soon, Takashi Kamada, and Charles S. Vairappan
- Abstract
Two new C15-acetogenins, 4-epi-isolaurallene (1) and 4-epi-itomanallene A (2) were isolated from a population of marine red alga Laurencia nangii Masuda from Carrington Reef. The structures of these compounds were determined intensively by NMR and HRESIMS data. Their configurations were elucidated by detailed comparison of chemical shifts, germinal protons splitting and NOE correlations with known and synthesized analogues. In addition, antibacterial activities of these compounds were evaluated. These compounds would serve as diastereomeric models for future reference. Since the isolaurallene, neolaurallene, 9-acetoxy-1,10,12-tribromo-4,7:6,13-bisepoxypentadeca-1,2-diene, itomanallene A and laurendecumallene A were isolated, compounds 1 and 2 were the sixth example of C15-acetogenin with dioxabicyclo[7.3.0]dodecene skeleton.
- Published
- 2020
30. Paralemnolins V and W, New Nardosinane-Type Sesquiterpenoids from a Bornean Soft Coral, Lemnalia sp
- Author
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Charles Santhanaraju Vairappan, Chin-Soon Phan, Takashi Kamada, and Kishio Hatai
- Subjects
Antifungal ,education.field_of_study ,010405 organic chemistry ,medicine.drug_class ,Chemistry ,Coral ,Paralemnolin ,Population ,Plant Science ,General Chemistry ,010402 general chemistry ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,0104 chemical sciences ,Lemnalia sp ,Botany ,medicine ,education ,Spectral data - Abstract
Two new nardosinane-type sesquiterpenoids, paralemnolin V (1) and paralemnolin W (2), along with five known sesquiterpenoids (3–7), were isolated from a population of Bornean soft coral Lemnalia sp. The structures of these metabolites were elucidated based on their NMR and HR-ESI-MS spectral data. These compounds were subjected to antibacterial and antifungal tests against eight bacterial and seven fungal strains.
- Published
- 2018
31. Cytotoxic Sesterterpenoids from Bornean Sponge Spongia sp
- Author
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Chin-Soon Phan, Takashi Kamada, Toshiyuki Hamada, and Charles S. Vairappan
- Subjects
Pharmacology ,Organic Chemistry ,s1t ,sesterterpenes ,adult t-cell leukemia ,Plant Science ,lcsh:QK1-989 ,sponge ,lcsh:Chemistry ,lcsh:QD241-441 ,lcsh:QD1-999 ,lcsh:Organic chemistry ,lcsh:Botany ,Drug Discovery ,borneo - Abstract
Four scalarane sesterterpenoids, scalarolide acetate (1), scalarolide (2), 12-O-deacetyl-12-epi-19-O-methylscalarin (3) and methyl 18-hydroxy-19-norscalar-16-en-20-carboxylate (4) were isolated from the Bornean spongeSpongiasp. The distinction between 12 a -OAc and 12 b -OAc, and 19-olide and 20-olide in sesterterpenes were revealed as well as previously not assigned relative configuration at 18-OH of4is reported herein for the first time. In addition, compounds1-3showed strong cytotoxic activities against adult T-cell leukemia (ATL), S1T cells. This is the first record of scalarane sesterterpenes from the Bornean sponge.
- Published
- 2018
32. Neoiriepentaol and nangenyne, halogenated diterpenoid and C15-acetogenin from red alga Laurencia nangii Masuda collected in Borneo
- Author
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Charles Santhanaraju Vairappan, Takashi Kamada, and Chin-Soon Phan
- Subjects
Haliphthoros ,biology ,Hypha ,010405 organic chemistry ,Stereochemistry ,Laurencia ,Plant Science ,Aquatic Science ,010402 general chemistry ,biology.organism_classification ,01 natural sciences ,Terpenoid ,0104 chemical sciences ,Neoirietetraol ,chemistry.chemical_compound ,chemistry ,Acetogenin ,Lagenidium thermophilum ,Marine fungi - Abstract
The red algal genus Laurencia is a prolific producer of halogenated secondary metabolites. A new tricyclic dibrominated diterpenoid, neoiriepentaol (1) and chlorinated C15-acetogenin, nangenyne (2), along with two known terpenoids, neoirietetraol (3) and dactyloxene A (4), were isolated from methanol crude extract of red alga Laurencia nangii. The structures were established based on one- and two-dimensional nuclear magnetic resonance (NMR), Fourier-transform infrared (FTIR), and high-resolution electrospray ionization mass spectrometry (HRESIMS) data. These compounds were screened against seven species of marine fungi. Compounds 1–3 exhibited activity against Lagenidium thermophilum and Haliphthoros sabahensis. Potent activity was showed by 1 with L. thermophilum hyphal inhibition at MIC value of 12.5 μg mL−1 and hyphal motility was observed at 50 μg mL−1 within 24 h.
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- 2018
33. Halogenated chamigrane sesquiterpenes from Bornean Laurencia majuscula
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Chin-Soon Phan, Vivian Shi-Ting Sien, Charles Santhanaraju Vairappan, and Takashi Kamada
- Subjects
Degree of unsaturation ,biology ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Electrospray ionization ,Laurencia ,Plant Science ,Red algae ,Aquatic Science ,biology.organism_classification ,Rhodomelaceae ,01 natural sciences ,0104 chemical sciences ,Terpene ,010404 medicinal & biomolecular chemistry ,Ceramiales ,Two-dimensional nuclear magnetic resonance spectroscopy - Abstract
The red alga genus Laurencia (Rhodomelaceae, Ceramiales) is known to produce and contain a rich diversity of halogenated secondary metabolites. These compounds are dominated by two major biosynthetic groups: terpenes (sesquiterpenes, diterpenes, and triterpenes) and C15-acetogenins. In the course of our investigation on red algae genus Laurencia from North Borneo Island, three new halogenated chamigranes, 7-aldehydelaurencenone B (1), 2-chloro-3-methoxy-α-chamigren-9-one (2), and laureborneone (3) along with five known halogenated derivatives such as [1(15)Z,2Z,4R,8S,9R]-8,15-dibromochamigra-1(15),2,11(12)-trien-9-ol (4), [1(15)E,2Z,4R,8S,9R]-8,15-dibromochamigra-1(15),2,11(12)-trien-9-ol (5), ma’ilion (6), laurencenone B (7), and 2-chloro-3-hydroxy-α-chamigren-9-one (8) were isolated from Laurencia majuscula. The structures of these compounds were determined based on spectroscopic data which consisted of infrared (FT-IR), H1-NMR, C13-NMR, H1-H1-COSY, HSQC, HMBC, and NOESY. In addition, high-resolution electrospray ionization mass spectrometry (HRESIMS) was done to calculate their molecular formula and unsaturation index. The anticancer potentials of these compounds were tested against three cancer cell lines, and their IC50 values were determined.
- Published
- 2018
34. Leucoxenols A and B, two new phenolics from Bornean medicinal plant Syzygium leucoxylon
- Author
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Kamsirah Jim Shamsudin, Julius Kulip, Takashi Kamada, Kishio Hatai, Charles Santhanaraju Vairappan, and Chin-Soon Phan
- Subjects
Antifungal ,Brachyura ,medicine.drug_class ,Lagenidium ,Syzygium ,Hyphae ,Pharmaceutical Science ,01 natural sciences ,Analytical Chemistry ,Phenols ,Borneo ,Drug Discovery ,medicine ,Animals ,Pharmacology ,Plants, Medicinal ,Molecular Structure ,biology ,Traditional medicine ,Plant Extracts ,010405 organic chemistry ,Organic Chemistry ,Myrtaceae ,General Medicine ,biology.organism_classification ,0104 chemical sciences ,Plant Leaves ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,Larva ,Molecular Medicine - Abstract
The medicinal plant, Syzygium leucoxylon or commonly known as Obah found in North Borneo was considered as traditional medicine by local committee. Two new phenolics, leucoxenols A (1) and B (2) were isolated and identified as major secondary metabolites from the leaves of S. leucoxylon. Their chemical structures were elucidated based on spectroscopic data such as NMR and HRESIMS. Furthermore, these compounds were active against selected strains of fungi.
- Published
- 2018
35. In vitro Inhibitory Effects of Two Bornean Medicinal Wild Gingers against Pathogenic Lagenidium thermophilum Infected Mud Crab Scylla tranquebarica
- Author
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Chin-Soon Phan, Kishio Hatai, Julius Kulip, Takashi Kamada, Lik Ming Lau, and Charles Santhanaraju Vairappan
- Subjects
0301 basic medicine ,Hyphal growth ,Oomycete ,Larva ,animal structures ,Scylla tranquebarica ,food.ingredient ,Hypha ,biology ,Zoospore ,fungi ,Public Health, Environmental and Occupational Health ,04 agricultural and veterinary sciences ,biology.organism_classification ,Plagiostachys ,Applied Microbiology and Biotechnology ,03 medical and health sciences ,030104 developmental biology ,food ,parasitic diseases ,Botany ,040102 fisheries ,0401 agriculture, forestry, and fisheries ,Lagenidium - Abstract
The antifungal activity of two Bornean medicinal wild gingers Plagiostachys megacarpa and Zingiber phillippsiae were examined against Lagenidium thermophilum. The most active extract was P. megacarpa at concentration of 320 µg/mL inhibiting both hyphal growth and zoospore production of L. thermophilum in 24 h. Toxicity tests were conducted using mud crab (Scylla tranquebarica) larva. Bath treatment of P. megacarpa at concentrations of 320 and 640 µg/mL for 24 h were highly effective against hyphae and zoospores of the strain and it is non-toxic to mud crab larva. Therefore, crude extracts P. megacarpa may be used as alternative treatment for marine Oomycete infection of mud crab.
- Published
- 2018
36. Atherothrombotic brain infarction developed in basilar artery fenestration: a case report
- Author
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Ken Sano, Takayuki Taniwaki, Akiko Yorita, Shiroh Miura, Shin-ichiroh Mori, Hiroshi Kida, Toshi Abe, Takashi Kamada, and Mitsuyoshi Ayabe
- Subjects
medicine.medical_specialty ,business.industry ,030204 cardiovascular system & hematology ,03 medical and health sciences ,0302 clinical medicine ,Brain infarction ,Internal medicine ,medicine.artery ,medicine ,Basilar artery ,Cardiology ,Fenestration ,business ,030217 neurology & neurosurgery - Published
- 2018
37. Bilateral cingulate cortices lesions in two autoantibodies directed against MOG (MOG-Ab)-positive patients
- Author
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Shinsuke Kikuchi, Yusuke Uchiyama, Azusa Irie, Takayuki Taniwaki, Shiroh Miura, Takashi Kamada, Toshiyuki Takahashi, Seiji Kurata, and Masaya Harada
- Subjects
Adult ,Male ,Cingulate cortex ,Pathology ,medicine.medical_specialty ,Demyelinating Autoimmune Diseases, CNS ,Fluid-attenuated inversion recovery ,Gyrus Cinguli ,Myelin oligodendrocyte glycoprotein ,03 medical and health sciences ,0302 clinical medicine ,immune system diseases ,Secondary Prevention ,medicine ,Humans ,030212 general & internal medicine ,Autoantibodies ,Tomography, Emission-Computed, Single-Photon ,High signal intensity ,biology ,business.industry ,Multiple sclerosis ,Autoantibody ,General Medicine ,medicine.disease ,Magnetic Resonance Imaging ,Steroid therapy ,nervous system ,Neurology ,Acute Disease ,Chronic Disease ,biology.protein ,Female ,Myelin-Oligodendrocyte Glycoprotein ,Steroids ,Neurology (clinical) ,business ,Perfusion ,030217 neurology & neurosurgery - Abstract
There are no specific radiologic features in MOG-Ab (autoantibodies directed against myelin oligodendrocyte glycoprotein)-associated diseases. We present two MOG-Ab-positive patients with symmetrical lesions in the bilateral cingulate cortex of the frontal and parietal lobes. Those lesions showed hyperperfusion in acute phase and hypoperfusion in chronic phase on brain SPECT. In both patients, steroid therapy was effective in acute phase and for prevention of recurrence. High signal in the bilateral cingulate cortex on MR T2-weighted and FLAIR images might to be one of the unique findings considered MOG-Ab associated diseases.
- Published
- 2019
38. Characteristics of olfactory dysfunction in patients with temporal lobe epilepsy
- Author
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Hideaki Tanaka, Ayako Motoki, Koichi Hagiwara, Shinji Ohara, Ayako Miyoshi, Hiroyuki Murai, Takashi Kamada, Naoki Akamatsu, Hiroshi Shigeto, and Tomoyuki Fumuro
- Subjects
Olfactory system ,medicine.medical_specialty ,Anosmia ,Olfaction ,Audiology ,behavioral disciplines and activities ,Temporal lobe ,Olfaction Disorders ,Behavioral Neuroscience ,Epilepsy ,Seizures ,Hyposmia ,medicine ,Humans ,Aged ,Hippocampal sclerosis ,business.industry ,medicine.disease ,Smell ,Epilepsy, Temporal Lobe ,Neurology ,Odor ,Odorants ,Neurology (clinical) ,medicine.symptom ,business ,psychological phenomena and processes - Abstract
OBJECTIVE To determine the characteristics of olfactory dysfunction in patients with temporal lobe epilepsy (TLE). METHODS Odor identification was assessed using the odor stick identification test for Japanese (OSIT-J, full score 12 points) in 65 patients with TLE and in 74 controls. RESULTS The mean OSIT-J score was significantly lower in patients with TLE (mean ± SD = 8.1 ± 2.8; median = 9) than in the control subjects (mean ± SD = 10.6 ± 1.1; median = 11) (P
- Published
- 2021
39. Chemical composition of Laurencia spp. collected from the Seto Inland Sea of Japan
- Author
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Hiroshi Matsuura, Tsuyoshi Abe, Takahiro Ishii, Yu Minamida, Kosuke Sato, Takashi Kamada, Yukimasa Yamagishi, Norio Kikuchi, Minoru Suzuki, and Aki Kato
- Subjects
biology ,010405 organic chemistry ,Laurencia ,Optically active ,biology.organism_classification ,Sesquiterpene ,01 natural sciences ,Biochemistry ,Laurinterol ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,chemistry ,Botany ,Laurencia sp ,Chemical composition ,Ecology, Evolution, Behavior and Systematics - Abstract
The chemical composition of three Laurencia spp., Laurencia sp., L. okamurae and L. saitoi, which were collected from the Seto Inland Sea of Japan, has been examined. Laurencia sp. collected from the coast of Matoba Park, Takehara, Hiroshima Prefecture, contained a brominated chamigrane-type sesquiterpene (1), named matobol, as the main metabolite. The structure of matobol was determined as (+)-(2R,3R,6R,10S)-2,10-dibromochamigr-7(14)-en-3-ol (1). This is the first time that the optically active 1 has been isolated from Laurencia. On the other hand, L. okamurae from the coast of Ikunoshima Island, Hiroshima Prefecture, produced laurinterol (2) that is a known cyclolaurane-type sesquiterpene characteristic to this species in Japan. L. saitoi from the coast of Matoba Park contained a known bromoallenic C15-acetogenin, neolaurallene (3).
- Published
- 2021
40. Cytotoxic sesquiterpenoids from soft soral capnella imbricata
- Author
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Chin-Soon Phan, Takahiro Ishii, Takashi Kamada, Toshiyuki Hamada, and Charles Santhanaraju Vairappan
- Subjects
sesquiterpene ,adult T-cell leukemia ,Coral ,Population ,Plant Science ,Biology ,Capnella imbricata ,Sesquiterpene ,01 natural sciences ,chemistry.chemical_compound ,Drug Discovery ,Botany ,Capnella ,education ,Pharmacology ,education.field_of_study ,010405 organic chemistry ,General Medicine ,biology.organism_classification ,capgermacrene H ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,chemistry ,soft coral ,cytotoxicity - Abstract
A new sesquiterpene, capgermacrene H (1) was isolated together with 7 other compounds, capgermacrenes A-G (2-8), from a population of soft coral Capnella imbricata collected from Mantanani Island, Sabah, Malaysia. The structure of this metabolite was elucidated based on spectroscopic data such as nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry. Capgermacrene A (2) showed potent cytotoxicity against adult T-cell leukemia, S1T cells at half-maximal inhibitory concentration of 0.79 µg/mL., 論文
- Published
- 2019
41. Reversible Conduction Failure in Anti-lactosylceramide-antibody-positive Combined Central and Peripheral Demyelination
- Author
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Takayuki Taniwaki, Tatsuro Mutoh, Taiga Moritaka, Ken Ichi Irie, Yusuke Uchiyama, Hiroshi Kida, Shiroh Miura, Takashi Kamada, Masaya Harada, Tomoaki Hoshino, and Sayuri Shima
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Weakness ,Constipation ,medicine.medical_treatment ,combined central and peripheral demyelination (CCPD) ,Case Report ,Gastroenterology ,lcsh:RC346-429 ,03 medical and health sciences ,Lactosylceramide ,0302 clinical medicine ,Internal medicine ,Sensation ,medicine ,music ,lcsh:Neurology. Diseases of the nervous system ,therapy ,music.instrument ,medicine.diagnostic_test ,biology ,total plasma exchange ,business.industry ,encephalomyeloradiculoneuropathy (EMRN) ,steroid ,lactosylceramide ,030104 developmental biology ,medicine.anatomical_structure ,Neurology ,Nerve conduction study ,biology.protein ,Abdomen ,Plasmapheresis ,reversible conduction failure (RCF) ,Neurology (clinical) ,medicine.symptom ,Antibody ,business ,030217 neurology & neurosurgery - Abstract
We describe a 60-year-old woman with combined central and peripheral demyelination who presented with obstinate constipation, weakness in the lower limbs, and a bilateral sensory disturbance below her chest followed by girdle sensation in the right region of the abdomen, which was responsive to steroid therapy and plasmapheresis. Serum anti-lactosylceramide antibody was positive without anti-neurofascin 155 antibody or anti-galactocerebroside antibody positivity. Two months later, the patient had a first relapse that was responsive to steroid treatment. A nerve conduction study confirmed reversible conduction failure (RCF) in both episodes. Our case is unique in that she had an RCF episode as well as some similarities to encephalomyeloradiculoneuropathy.
- Published
- 2019
42. 16-Hydroxycembra-1,3,7,11-tetraene, a new Cembrane Diterpene from Malaysian Soft Coral Genus Sarcophyton
- Author
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Chin-Soon Phan, Takashi Kamada, Tengku Sifzizul Tengku Muhammad, Charles Santhanaraju Vairappan, and Hoe Seng Tin
- Subjects
Sarcophytoxide ,Staphylococcus aureus ,Stereochemistry ,Coral ,Alcyoniidae ,Plant Science ,Microbial Sensitivity Tests ,medicine.disease_cause ,01 natural sciences ,chemistry.chemical_compound ,Genus ,Drug Discovery ,medicine ,Escherichia coli ,Animals ,Pharmacology ,biology ,Molecular Structure ,010405 organic chemistry ,Sarcophyton ,General Medicine ,biology.organism_classification ,Anthozoa ,0104 chemical sciences ,Anti-Bacterial Agents ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,chemistry ,Diterpene ,Diterpenes ,Bacteria - Abstract
One new cembrane diterpene, 16-hydroxycembra-1,3,7,11-tetraene (1), along with three known compounds, 15-hydroxycembra-1,3,7,11-tetraene (2), sarcophine (3) and sarcophytoxide (4) were isolated from Sarcophyton sp. collected from Karah Island, Terengganu, West Malaysia. Their structures were elucidated based on spectroscopic data. Activities of these compounds against antibacterial resistant clinical bacteria are reported. Only 1 exhibited inhibition against Staphylococcus aureus.
- Published
- 2019
43. Two new epimers of C15-acetogenin, 4-epi-isolaurallene and 4-epi-itomanallene A as diastereomeric model
- Author
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Charles Santhanaraju Vairappan, Chin-Soon Phan, and Takashi Kamada
- Subjects
education.field_of_study ,biology ,010405 organic chemistry ,Stereochemistry ,Chemistry ,Chemical shift ,Organic Chemistry ,Population ,Diastereomer ,Laurencia ,Plant Science ,biology.organism_classification ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Analytical Chemistry ,Isolaurallene ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,Acetogenin ,Epimer ,education - Abstract
Two new C15-acetogenins, 4-epi-isolaurallene (1) and 4-epi-itomanallene A (2) were isolated from a population of marine red alga Laurencia nangii Masuda from Carrington Reef. The structures of these compounds were determined intensively by NMR and HRESIMS data. Their configurations were elucidated by detailed comparison of chemical shifts, germinal protons splitting and NOE correlations with known and synthesized analogues. In addition, antibacterial activities of these compounds were evaluated. These compounds would serve as diastereomeric models for future reference. Since the isolaurallene, neolaurallene, 9-acetoxy-1,10,12-tribromo-4,7:6,13-bisepoxypentadeca-1,2-diene, itomanallene A and laurendecumallene A were isolated, compounds 1 and 2 were the sixth example of C15-acetogenin with dioxabicyclo[7.3.0]dodecene skeleton.
- Published
- 2019
- Full Text
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44. A new bioactive cembranoid sarcophytonolide V from Bornean soft coral genus Sarcophyton
- Author
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Kazuki Tani, Takashi Kamada, Phan, Chin Soon, Charles S. Vairappan, Kazuki Tani, Takashi Kamada, Phan, Chin Soon, and Charles S. Vairappan
- Abstract
A new cembranolide diterpene, sarcophytonolide V (1), along with 6 known compounds, isosarcophytonolide D (2), (4Z,8S*,9R*,12E,14E) -9-hydroxy-1- (prop-1-en-2-yl) -8,12- dimethyl- oxabicyclo[9.3.2]-hexadeca-4,12,14-trien-18-one (3), (7E,11E)-3,4-epoxy-7,11, 15- cembratriene (4), (1S*,3S*,4S*,7E,11E)-3,4-epoxy-13-oxo-7,11,15-cembratriene (5), (-) -eunicenone (6), and 2-[(E,E,E)-7′, 8′-epoxy-4′,8′,12′ -trimethylcyclotetradeca- 1′,3′,11′- trienyl] propan-2-ol (7) were isolated from the Bornean soft coral Sarcophyton sp. Their structures were elucidated based on spectroscopic data, such as nuclear magnetic resonance (NMR) and high resolution electron spray ionization mass spectroscopy (HRESIMS). These compounds were evaluated for their biological activity against marine pathogenic fungi.
- Published
- 2019
45. Leucoxenols A and B, two new phenolics from Bornean medicinal plant Syzygium leucoxylon
- Author
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Kamsirah Jim Shamsudin, Chin-Soon Phan, Julius Kulip, Kishio Hatai, Charles Santhanaraju Vairappan, Takashi Kamada, Kamsirah Jim Shamsudin, Chin-Soon Phan, Julius Kulip, Kishio Hatai, Charles Santhanaraju Vairappan, and Takashi Kamada
- Abstract
The medicinal plant, Syzygium leucoxylon or commonly known as Obah found in North Borneo was considered as traditional medicine by local committee. Two new phenolics, leucoxenols A (1) and B (2) were isolated and identified as major secondary metabolites from the leaves of S. leucoxylon. Their chemical structures were elucidated based on spectroscopic data such as NMR and HRESIMS. Furthermore, these compounds were active against selected strains of fungi.
- Published
- 2019
46. Cytotoxic sesquiterpenoids from soft coral Capnella imbricata
- Author
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Phan, Chin Soon, Takashi Kamada, Takahiro Ishii, Toshiyuki Hamada, Charles Santhanaraju Vairappan, Phan, Chin Soon, Takashi Kamada, Takahiro Ishii, Toshiyuki Hamada, and Charles Santhanaraju Vairappan
- Abstract
A new sesquiterpene, capgermacrene H (1) was isolated together with 7 other compounds, capgermacrenes A-G (2-8), from a population of soft coral Capnella imbricata collected from Mantanani Island, Sabah, Malaysia. The structure of this metabolite was elucidated based on spectroscopic data such as nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry. Capgermacrene A (2) showed potent cytotoxicity against adult T-cell leukemia, S1T cells at half-maximal inhibitory concentration of 0.79 µg/mL.
- Published
- 2019
47. Cytotoxicity and antibacterial poteltial of haligenated chamigrenes from Malaysian red algae, Laurencia majuscula
- Author
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Takashi Kamada, Phan, Chin Soon, Tatsufumi Okino, Charles Santhanaraju Vairappan, Takashi Kamada, Phan, Chin Soon, Tatsufumi Okino, and Charles Santhanaraju Vairappan
- Abstract
Red algae of the genus Laurencia have been known to produce a wide array of bioactive secondary metabolites. Here, we report the isolation of two new halogenated chamigrenes, lauremantanones A (1) and B (2), along with seven known compounds, dendroidiol (3), (+)-elatol (4), cartilagineol (5), obtusol (6), (+)-laurencenone B (7), 2-chloro-3-hydroxy- α-chamigren-9- one (8), and puertitol A (9), from a population of Laurencia majuscula (Harvey) Lucas from Mantanani Island (North Borneo). The structures of the two new metabolites were determined based on spectroscopic data (IR, 1D and 2D NMR, and MS). Compounds isolated from this alga exhibited potent cytotoxic (HeLa, MCF-7, P-388) and antibacterial (against antibiotic-resistant clinical bacteria) activities. The major metabolite of this population has significant importance in the geographical distribution of this species globally.
- Published
- 2019
48. New cembrane-type diterpenoids from Bornean soft coral N ephthea sp. with antifungal activity against Lagenidium thermophilum
- Author
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Kazuka Tani, Takashi Kamada, Phan, Chin Soon, Charles Santhanaraju Vairappan, Kazuka Tani, Takashi Kamada, Phan, Chin Soon, and Charles Santhanaraju Vairappan
- Abstract
Three new cembrane diterpenes, nephthecrassocolides A-B (1–2) and 6-acetoxy nephthenol acetate (3) along with three known compounds, 6-acetoxy-7,8-epoxy nephthenol acetate (4), epoxy nephthenol acetate (5) and nephthenol (6) were isolated from one population of Nephthea sp. Their structures were elucidated based on spectroscopic data analysis and the antifungal activities of compounds 1–6 were evaluated.
- Published
- 2019
49. Aaptamine-related alkaloid from the marine sponge Aaptos aaptos
- Author
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Toshiyuki Hamada, Yoshito Matsumoto, Phan, Chin Soon, Takashi Kamada, Satoaki Onitsuka, Hiroaki Okamura, Tetsuo Iwagawa, Naomichi Arima, Fumito Tani, Charles S. Vairappan, Toshiyuki Hamada, Yoshito Matsumoto, Phan, Chin Soon, Takashi Kamada, Satoaki Onitsuka, Hiroaki Okamura, Tetsuo Iwagawa, Naomichi Arima, Fumito Tani, and Charles S. Vairappan
- Abstract
A new aaptamine-related alkaloid, 1,3-dioxolo [4,5-d] benzo [de]-1,6-naphthyridine (methylenedioxyaaptamine, 1), was isolated from the organic extracts of the Bornean marine sponge Aaptos aaptos, together with a known aaptamine derivative, 8,9,9-trimethoxy-9H-benzo [de]-1,6-naphthyridine (2). The structure of compound 1 was elucidated by interpretation of its spectroscopic data. Two compounds were tested for their cytotoxic potentials against adult T-cell leukemia (ATL) cells, and compound 1 showed moderate cytotoxic potential.
- Published
- 2019
50. 12Epi -9deacetoxyxenicin, new cytotoxic diterpenoid from a Bornean soft coral Xenia sp
- Author
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Phan, Chin Soon, Takashi Kamada, Takahiro, Ishii, Toshiyuki Hamada, Charles Santhanaraju Vairappan, Phan, Chin Soon, Takashi Kamada, Takahiro, Ishii, Toshiyuki Hamada, and Charles Santhanaraju Vairappan
- Abstract
One new compound, 12-epi-9-deacetoxyxenicin (1) along with a hydroperoxide product, 12-epi-9-deacetoxy-8-hydroperoxyxenicin (2) and two known sesquiterpenoids (3–4) were isolated from a population of Bornean soft coral Xenia sp. The structures of these secondary metabolites were elucidated based on their spectroscopic data. Compounds 1 and 2 showed cytotoxic activity against ATL cell line, S1T. In addition, compound 3 exhibited hyphal inhibition of Lagenidium thermophilum.
- Published
- 2019
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