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Tian Y, Kong B, Zhu W, Su S, Kan Y. Expression of steroidogenic factor 1 (SF-1) and steroidogenic acute regulatory protein (StAR) in endometriosis is associated with endometriosis severity. J Int Med Res 2010; 37:1389-95. [PMID: 19930843 DOI: 10.1177/147323000903700513] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
This study was designed to investigate the levels of expression of steroidogenic factor 1 (SF-1) and steroidogenic acute regulatory protein (StAR) in endometriosis, and to explore the association between these two factors and the menstrual cycle and the severity of endometriosis. Levels of SF-1 and StAR protein were evaluated using immunohistochemistry in 38 cases of endometriosis with ectopic endometria and in 25 normal endometria (controls). The SF-1 and StAR protein levels were significantly higher in ectopic endometria than in normal endometria. There was a significant correlation between the level of SF-1 and StAR in ectopic endometriotic tissues. It is concluded that protein levels of SF-1 and StAR are upregulated in ectopic endometria and are significantly correlated with the severity of endometriosis.
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Ou K, Kan Y. P198 MRI imaging of inguinal endometriosis - 2 case reports. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)61689-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kan Y, Gökbulut A, Kartal M, Konuklugil B, Yılmaz G. Development and Validation of a LC Method for the Analysis of Phenolic Acids in Turkish Salvia Species. Chromatographia 2009. [DOI: 10.1365/s10337-009-1079-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Orhan I, Senol FS, Gülpinar AR, Kartal M, Sekeroglu N, Deveci M, Kan Y, Sener B. Acetylcholinesterase inhibitory and antioxidant properties of Cyclotrichium niveum, Thymus praecox subsp. caucasicus var. caucasicus, Echinacea purpurea and E. pallida. Food Chem Toxicol 2009; 47:1304-10. [PMID: 19285534 DOI: 10.1016/j.fct.2009.03.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 02/20/2009] [Accepted: 03/02/2009] [Indexed: 12/24/2022]
Abstract
The dichloromethane, ethyl acetate, ethanol, and aqueous extracts of Cyclotrichium niveum (CN) and Thymus praecox subsp. caucasicus var. caucasicus (TP), Echinacea purpurea (EPU), and E. pallida (EPA) along with the essential oils of CN and TP were assessed for their anti-acetylcholinesterase (AChE) and antioxidant activities. AChE inhibition was estimated using spectrophotometric method of Ellman. Antioxidant activity was evaluated by 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and ferrous ion-chelating power tests. Ferric-reducing antioxidant power (FRAP) of CN and TP were also tested. CN essential oil was found to contain isomenthone (56.21%) and pulegone (19.76%). The ethyl acetate (83.11-87.98%) and dichloromethane (73.45-84.02%) extracts of CN showed the highest AChE inhibition. The ethyl acetate and ethanol extracts of TP exerted significant DPPH scavenger effect. The water extracts of CN and TP and the chloroform extract of the aerial parts of EPU displayed the highest ferrous ion-chelating effect. The leaf and flower essential oils of TP had the best FRAP.
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Kong B, Tian Y, Zhu W, Su S, Kan Y. Effects of Celecoxib and Nimesulide on the Proliferation of Ectopic Endometrial Stromal Cells in vitro. J Int Med Res 2008; 36:1032-8. [PMID: 18831898 DOI: 10.1177/147323000803600521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The effects of cyclooxygenase 2 (COX-2) selective inhibitors on the proliferation of ectopic endometrial stromal cells in vitro were investigated. Ectopic endometrial stromal cells were treated with either celecoxib or nimesulide for 24 and 48 h. The results showed that (i) both celecoxib and nimesulide inhibited the proliferation of ectopic endometrial stromal cells in vitro in a time- and dose-dependent manner; (ii) the expression of prostaglandin E2 was significantly inhibited by both celecoxib and nimesulide in a dose-dependent manner; (iii) the percentage of apoptotic cells was significantly higher for cells treated with celecoxib or nimesulide than for untreated cells; and (iv) the percentage of the cells in the G0/G1 phase increased after the cells were treated with either agent in a dose-dependent manner. These data suggest that celecoxib and nimesulide inhibited proliferation of ectopic endometrial stromal cells by inducing apoptosis and blocking the cell cycle at the G0/G1 phase.
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Kan Y, Gökbulut A, Kartal M, Konuklugil B, Yılmaz G. Development and Validation of a LC Method for the Analysis of Phenolic Acids in Turkish Salvia Species. Chromatographia 2007. [DOI: 10.1365/s10337-007-0278-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Chiang A, Chuang Y, Kan Y, Fang C. 236. J Minim Invasive Gynecol 2005. [DOI: 10.1016/j.jmig.2005.07.257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Chuang Y, Kan Y, Fang C. 311. J Minim Invasive Gynecol 2005. [DOI: 10.1016/j.jmig.2005.07.313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kan Y, Mimura M, Kamijima K, Kawamura M. Recognition of emotion from moving facial and prosodic stimuli in depressed patients. J Neurol Neurosurg Psychiatry 2004; 75:1667-71. [PMID: 15548479 PMCID: PMC1738863 DOI: 10.1136/jnnp.2004.036079] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND It has been suggested that depressed patients have a "negative bias" in recognising other people's emotions; however, the detailed structure of this negative bias is not fully understood. OBJECTIVES To examine the ability of depressed patients to recognise emotion, using moving facial and prosodic expressions of emotion. METHODS 16 depressed patients and 20 matched (non-depressed) controls selected one basic emotion (happiness, sadness, anger, fear, surprise, or disgust) that best described the emotional state represented by moving face and prosody. RESULTS There was no significant difference between depressed patients and controls in their recognition of facial expressions of emotion. However, the depressed patients were impaired relative to controls in their recognition of surprise from prosodic emotions, judging it to be more negative. CONCLUSIONS We suggest that depressed patients tend to interpret neutral emotions, such as surprise, as negative. Considering that the deficit was seen only for prosodic emotive stimuli, it would appear that stimulus clarity influences the recognition of emotion. These findings provide valuable information on how depressed patients behave in complicated emotional and social situations.
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Kyriakides C, Kan Y, Kerle M, Cheshire NJ, Mansfield AO, Wolfe JHN. 11-year experience with anatomical and extra-anatomical repair of mycotic aortic aneurysms. Eur J Vasc Endovasc Surg 2004; 27:585-9. [PMID: 15121107 DOI: 10.1016/j.ejvs.2004.02.024] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2004] [Indexed: 11/20/2022]
Abstract
BACKGROUND We have reviewed our management, of both ruptured and non-ruptured, abdominal and thoraco-abdominal mycotic aneurysms in order to determine the safety and efficacy of in situ and extra-anatomical prosthetic repairs. METHODS Data regarding presenting symptoms, investigations, operative techniques and outcome, were collected on patients treated at a singe centre over 11 years. RESULTS There were 11 men and four women, with a median age of 70 years (range, 24-79). All but one patient were symptomatic and six had a contained leak on admission. In six patients no organisms were identified in either blood or tissue cultures. Pre-operative CT identified; four infra-renal, four juxta-renal, three (Crawford thoraco-abdominal) type IV, three type III and one type II, aortic aneurysms. Thirteen were repaired with in situ prostheses and two required axillo-femoral prosthetic grafts. There were four early deaths. All surviving patients have been followed-up for a median duration of 38 months (range 1/2-112 months). There were two late deaths at 3 months (juxta-renal) and at 2 years (type III), the latter relating to graft infection. CONCLUSIONS In the absence of uncontrolled sepsis, repair of mycotic aortic aneurysms using prosthetic grafts can achieve durable results.
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Kan Y, Kyriakides C, Kerle M, Cheshire N, Mansfield A, Wolfe J. Six of the Best, Vascular 25. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.89.s.1.20_6.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Igarashi Y, Kan Y, Fujii K, Fujita T, Harada K, Naoki H, Tabata H, Onaka H, Furumai T. Goadsporin, a chemical substance which promotes secondary metabolism and Morphogenesis in streptomycetes. II. Structure determination. J Antibiot (Tokyo) 2001; 54:1045-53. [PMID: 11858659 DOI: 10.7164/antibiotics.54.1045] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure of goadsporin was determined by using spectroscopic techniques. NMR analysis revealed that goadsporin consists of 19 amino acids, two of which are dehydroalanines (Deala), and six of which are cyclized to oxazoles (Oxz) and thiazoles (Thz) by dehydrative cyclization and dehydrogenation from serine, threonine and cysteine. NMR analysis established seven partial structures, and their sequence was determined by CID-MS/MS. Negative mode FAB-MS/MS gave product ions arising from charge-remote fragmentation that allowed determination of the sequence of the amino acid components as AcNH-Ala-MeOxz-Val-Deala-MeOxz-Ile-Leu-Thz-Ser-Gly-Gly-MeOxz-Leu-Deala-Oxz-Ala-Gly-Thz-Val-OH. The chiral amino acids were determined by the advanced Marfey's method to have L-configurations.
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Ukena T, Satake M, Usami M, Oshima Y, Naoki H, Fujita T, Kan Y, Yasumoto T. Structure elucidation of ostreocin D, a palytoxin analog isolated from the dinoflagellate Ostreopsis siamensis. Biosci Biotechnol Biochem 2001; 65:2585-8. [PMID: 11791741 DOI: 10.1271/bbb.65.2585] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The structure of ostreocin D, a palytoxin analog isolated from the marine dinoflagellate Ostreopsis siamensis, was found to be 42-hydroxy-3,26-didemethyl-19,44-dideoxypalytoxin by detailed 2D NMR analyses of intact ostreocin D and its ozonolysis products. Partial stereochemical assignments were done. This result indicates that the dinoflagellate O. siamensis is one of the biogenetic origins of palytoxin.
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Uchino A, Sawada A, Takase Y, Kan Y, Matsuo M, Kudo S. Supraclinoid carotid dissection in a pediatric patient. Clin Imaging 2001; 25:385-7. [PMID: 11733149 DOI: 10.1016/s0899-7071(01)00341-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The authors present the case of a 13-year-old boy with a left temporal lobe infarction that developed during a 400-m run. Magnetic resonance (MR) angiography showed segmental narrowing of the left supraclinoid internal carotid artery (ICA) and a duplicated left middle cerebral artery (MCA). MR angiographic source images revealed a crescent-shaped left carotid lumen, indicative of a supraclinoid carotid dissection.
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Tamamura H, Sugioka M, Odagaki Y, Omagari A, Kan Y, Oishi S, Nakashima H, Yamamoto N, Peiper SC, Hamanaka N, Otaka A, Fujii N. Conformational study of a highly specific CXCR4 inhibitor, T140, disclosing the close proximity of its intrinsic pharmacophores associated with strong anti-HIV activity. Bioorg Med Chem Lett 2001; 11:359-62. [PMID: 11212110 DOI: 10.1016/s0960-894x(00)00664-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We report the solution structure of T140, a truncated polyphemusin peptide analogue that efficiently inhibits infection of target cells by T-cell line-tropic strains of HIV-1 through its specific binding to a chemokine receptor, CXCR4. Nuclear magnetic resonance analysis and molecular dynamic calculations revealed that T140 has a rigidly structured conformation constituted by an antiparallel beta-sheet and a type II' beta-turn. A protuberance is formed on one side of the beta-sheet by the side-chain functional groups of the three amino acid residues (L-3-(2-naphthyl)alanine, Tyr5 and Arg14), each of which is indispensable for strong anti-HIV activity. These findings provide a rationale to dissect the structural basis for the ability of this compound to block the interaction between CXCR4 and envelope glycoproteins from T-tropic strains of HIV-1.
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Nakayama M, Koshioka M, Yoshida H, Kan Y, Fukui Y, Koike A, Yamaguchi M. Cyclic malyl anthocyanins in Dianthus caryophyllus. PHYTOCHEMISTRY 2000; 55:937-939. [PMID: 11140528 DOI: 10.1016/s0031-9422(00)00263-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
3,5-Di-O-(beta-glucopyranosyl) pelargonidin 6''-O-4,6'''-O-1-cyclic malate and a previously reported cyanidin equivalent, 3,5-di-O-(beta-glucopyranosyl) cyanidin 6''-O-4,6'''-O-1-cyclic malate were identified from petals of deep pink and red-purple flower cultivars of Dianthus caryophyllus, respectively.
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Kan Y, Sakamoto B, Fujita T, Nagai H. New malyngamides from the Hawaiian cyanobacterium Lyngbya majuscula. JOURNAL OF NATURAL PRODUCTS 2000; 63:1599-1602. [PMID: 11141095 DOI: 10.1021/np000250t] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Isomalyngamides A and B (1, 2) were isolated and characterized from a collection of the cyanobacterium Lyngbya majuscula from Hawaiian waters. These compounds represent a new type of malyngamide, similar to malyngamides Q and R, in which the conformation of the chloromethylene group is opposite from the majority of previously reported malyngamides. The geometry of the chloromethylene moiety was elucidated from the long-range coupling constants ((3)J(C)(-)(H)) obtained from editing-HETLOC and phase-sensitive HMBC experiments. Isomalyngamides A and B (1, 2) showed lethal toxicity to crayfish.
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Konno K, Fujishima T, Maki S, Liu Z, Miura D, Chokki M, Ishizuka S, Yamaguchi K, Kan Y, Kurihara M, Miyata N, Smith C, DeLuca HF, Takayama H. Synthesis, biological evaluation, and conformational analysis of A-ring diastereomers of 2-methyl-1,25-dihydroxyvitamin D(3) and their 20-epimers: unique activity profiles depending on the stereochemistry of the A-ring and at C-20. J Med Chem 2000; 43:4247-65. [PMID: 11063621 DOI: 10.1021/jm000261j] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
All eight possible A-ring diastereomers of 2-methyl-1, 25-dihydroxyvitamin D(3) (2) and 2-methyl-20-epi-1, 25-dihydroxyvitamin D(3) (3) were convergently synthesized. The A-ring enyne synthons 19 were synthesized starting with methyl (S)-(+)- or (R)-(-)-3-hydroxy-2-methylpropionate (8). This was converted to the alcohol 14 as a 1:1 epimeric mixture in several steps. After having been separated by column chromatography, each isomer led to the requisite A-ring enyne synthons 19 again as 1:1 mixtures at C-1. Coupling of the resulting A-ring enynes 20a-h with the CD-ring portions 5a,b in the presence of a Pd catalyst afforded the 2-methyl analogues 2a-h and 3a-h in good yield. In this way, all possible A-ring diastereomers were synthesized. The synthesized analogues were biologically evaluated both in vitro and in vivo. The potency was highly dependent on the stereochemistry of each isomer. In particular, the alpha alpha beta-isomer 2g exhibited 4-fold higher potency than 1 alpha,25-dihydroxyvitamin D(3) (1) both in bovine thymus VDR binding and in elevation of rat serum calcium concentration and was twice as potent as the parent compound in HL-60 cell differentiation. Furthermore, its 20-epimer, that is, 20-epi-alpha alpha beta 3g, exhibited exceptionally high activities: 12-fold higher in VDR binding affinity, 7-fold higher in calcium mobilization, and 590-fold higher in HL-60 cell differentiation, as compared to 1 alpha,25-dihydroxyvitamin D(3) (1). Accordingly, the double modification of 2-methyl substitution and 20-epimerization resulted in unique activity profiles. Conformational analysis of the A-ring by (1)H NMR and an X-ray crystallographic analysis of the alpha alpha beta-isomer 2g are also described.
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Kim WK, Kan Y, Ganea D, Hart RP, Gozes I, Jonakait GM. Vasoactive intestinal peptide and pituitary adenylyl cyclase-activating polypeptide inhibit tumor necrosis factor-alpha production in injured spinal cord and in activated microglia via a cAMP-dependent pathway. J Neurosci 2000; 20:3622-30. [PMID: 10804204 PMCID: PMC6772690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/1999] [Revised: 02/29/2000] [Accepted: 03/01/2000] [Indexed: 02/16/2023] Open
Abstract
Tumor necrosis factor-alpha (TNF-alpha) production accompanies CNS insults of all kinds. Because the neuropeptide vasoactive intestinal peptide (VIP) and the structurally related peptide pituitary adenylyl cyclase-activating polypeptide (PACAP) have potent anti-inflammatory effects in the periphery, we investigated whether these effects extend to the CNS. TNF-alpha mRNA was induced within 2 hr after rat spinal cord transection, and its upregulation was suppressed by a synthetic VIP receptor agonist. Cultured rat microglia were used to examine the mechanisms underlying this inhibition because microglia are the likely source of TNF-alpha in injured CNS. In culture, increases in TNF-alpha mRNA resulting from lipopolysaccharide (LPS) stimulation were reduced significantly by 10(-7) m VIP and completely eliminated by PACAP at the same concentration. TNF-alpha protein levels were reduced 90% by VIP or PACAP at 10(-7) m. An antagonist of VPAC(1) receptors blocked the action of VIP and PACAP, and a PAC(1) antagonist blocked the action of PACAP. A direct demonstration of VIP binding on microglia and the existence of mRNAs for VPAC(1) and PAC(1) (but not VPAC(2)) receptors argue for a receptor-mediated effect. The action of VIP is cAMP-mediated because (1) activation of cAMP by forskolin mimics the action; (2) PKA inhibition by H89 reverses the neuropeptide-induced inhibition; and (3) the lipophilic neuropeptide mimic, stearyl-norleucine(17) VIP (SNV), which does not use a cAMP-mediated pathway, fails to duplicate the inhibition. We conclude that VIP and PACAP inhibit the production of TNF-alpha from activated microglia by a cAMP-dependent pathway.
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Igarashi Y, Takagi K, Kan Y, Fujii K, Harada K, Furumai T, Oki T. Arisostatins A and B, new members of tetrocarcin class of antibiotics from Micromonospora sp. TP-A0316. II. Structure determination. J Antibiot (Tokyo) 2000; 53:233-40. [PMID: 10819293 DOI: 10.7164/antibiotics.53.233] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Structures of arisostatins A and B were determined by spectroscopic analyses. Arisostatins were found to be new analogs of tetrocarcin A and possess an iso-butanoyldigitoxose unit instead of the acetyldigitoxose one. NMR analyses of arisostatins and tetrocarcin A led to the revision of the anomeric configurations in the tetrasaccharide moiety of tetrocarcin A.
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Inohara-Ochiai M, Okada M, Nakayama T, Hemmi H, Ueda T, Iwashita T, Kan Y, Shibano Y, Ashikari T, Nishino T. An active-site mutation causes enhanced reactivity and altered regiospecificity of transglucosylation catalyzed by the Bacillus sp. SAM1606 α-glucosidase. J Biosci Bioeng 2000; 89:431-7. [PMID: 16232773 DOI: 10.1016/s1389-1723(00)89092-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2000] [Accepted: 02/08/2000] [Indexed: 10/18/2022]
Abstract
Bacillus sp. SAM1606 alpha-glucosidase catalyzes the transglucosylation of sucrose to produce three regioisomers of the glucosylsucroses, with theanderose (6-O(G)-glucosylsucrose) as the most abundant transfer product. To find the active-site amino acid residues which can affect the reactivity and regiospecificity of the glucosyl transfer, 16 mutants with amino acid substitutions near the active site were allowed to react with 1.75 M sucrose at 60 degrees C, pH 6.0, and the course of transglucosylation as well as the product specificity were analyzed. The sites of the amino acid substitutions were selected by comparing the conserved amino acid sequences located near the active site of the SAM1606 enzyme with those of the Bacillus oligo-1,6-glucosidases (O16G), which have very high amino acid sequence similarities near the active site but have a distinct substrate specificity. The results showed that, among the mutated SAM1606 enzymes examined, only the mutants with substitution of Gly273 with Pro showed an altered reactivity and specificity of transglucosylation; these mutants exhibited a significantly enhanced initial velocity of glucosyl transfer, yielding isomelezitose (6-O(F)-glucosylsucrose) instead of theanderose as the major transfer product. These results indicate that the substitution of Gly273 with Pro critically governs the enhanced reactivity and altered specificity of the transglucosylation. The notion that the amino acid residue at this position is the determinant of the glucosyl-transfer specificity was further confirmed by observation that the Bacillus cereus O16G, which has a proline at the corresponding position, produced isomelezitose as the major transfer product during transglucosylation with sucrose.
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Horgen FD, delos Santos DB, Goetz G, Sakamoto B, Kan Y, Nagai H, Scheuer PJ. A new depsipeptide from the sacoglossan mollusk Elysia ornata and the green alga Bryopsis species. JOURNAL OF NATURAL PRODUCTS 2000; 63:152-154. [PMID: 10650101 DOI: 10.1021/np990402o] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A new cyclic depsipeptide, kahalalide O (1), was isolated from the sacoglossan Elysia ornata and its algal diet Bryopsis sp. The structure was elucidated primarily by NMR and MS spectral methods, and the stereochemistry of the amino acid residues was determined by chiral HPLC and Marfey analyses. Unlike the related metabolite kahalalide F, which is in development as a potential anticancer agent, kahalalide O (1) was inactive in arresting the growth of P-388, A549, HT29, and MEL28 cancer cell lines in vitro.
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Kan Y, Fujita T, Sakamoto B, Hokama Y, Nagai H. Kahalalide K: A new cyclic depsipeptide from the hawaiian green alga bryopsis species. JOURNAL OF NATURAL PRODUCTS 1999; 62:1169-1172. [PMID: 10479330 DOI: 10.1021/np990053y] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Kahalalide K (1), a new cyclic depsipeptide, was isolated from the Hawaiian green alga Bryopsis sp. Kahalalide K was determined to possess a new array of three L- and three D-amino acids, including a 3-hydroxy-9-methyldecanoic acid that had been previously reported in kahalalides E, H, and J.
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Henderson PT, Jones D, Hampikian G, Kan Y, Schuster GB. Long-distance charge transport in duplex DNA: the phonon-assisted polaron-like hopping mechanism. Proc Natl Acad Sci U S A 1999; 96:8353-8. [PMID: 10411879 PMCID: PMC17521 DOI: 10.1073/pnas.96.15.8353] [Citation(s) in RCA: 367] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An anthraquinone-linked duplex DNA oligomer containing 60 base pairs was synthesized by PCR. The strand complementary to the quinone-containing strand has four isolated GG steps, which serve as traps for a migrating radical cation. Irradiation of the quinone leads to electron transfer from the DNA to the quinone forming the anthraquinone radical anion and a base radical cation. The radical cation migrates through the DNA, causing reaction at GG steps revealed as strand breaks. The efficiency of strand cleavage falls off exponentially with distance from the quinone (slope = -0.02 A(-1)). This finding necessitates reinterpretation of mechanisms proposed for radical cation migration in DNA. We propose that radical cations form self-trapped polarons that migrate by thermally activated hopping.
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Harada M, Kan Y, Naoki H, Fukui Y, Kageyama N, Nakai M, Miki W, Kiso Y. Identification of the major antioxidative metabolites in biological fluids of the rat with ingested (+)-catechin and (-)-epicatechin. Biosci Biotechnol Biochem 1999; 63:973-7. [PMID: 10427682 DOI: 10.1271/bbb.63.973] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
(+)-Catechin and (-)-epicatechin are known to be biologically effective antioxidants present in the human diet, particularly in wine and tea. We studied the metabolism of these compounds to elucidate the truly active structures in biological fluids by their oral administration to rats. Without any treatment with beta-glucuronidase and sulfatase, a pair of metabolites were detected at much higher concentrations in the plasma, bile, and urine than the originally ingested compounds. Each major metabolite found in the plasma at the highest concentration was excreted in both the bile and urine, and was purified from urine. Their chemical structures were established to be (+)-catechin 5-O-beta-glucuronide and (-)-epicatechin 5-O-beta-glucuronide by MS and NMR analyses. These glucuronide conjugates exhibited high antioxidative activities as superoxide anion radical scavengers like their parent compounds. It is concluded that (+)-catechin 5-O-beta-glucuronide and (-)-epicatechin 5-O-beta-glucuronide are the biologically active in vivo structures of the ingested polyphenolic antioxidants.
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