O-demethylation of meso-dimethyl dihydroguaiaretic acid in spodoptera litura

Miyazawa, M

doi:10.1016/s0031-9422(97)00447-0

Cited by 3 publications

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“…1). Previous studies implied that common cuckoos mate multiply (1,5,13), and a recent molecular study has shown 29. E. Oldmixon, J. P. Butler, F. C. Hoppin,].…”

Section: Host-race Formation In the Common Cuckoo Karen Marchetti* Hmentioning

confidence: 99%

“…The first step in host-race formation is the exploitation of a new host, followed by adaptation to that host. In central Japan, cuckoos began to exploit the azurewinged magpie (Cyanopica cj~ana) 20 to 30 years ago as a result of expansion of the magpie's breeding range (4)(5)(6). Cuckoos also utilize two other hosts in the area: the great reed warbler (Aci.ocephalus a~undinaceus) and the bull-headed shrike (Lanius bucephaltis) (4-7).…”

Section: Host-race Formation In the Common Cuckoo Karen Marchetti* Hmentioning

confidence: 99%

“…The high gene flow arises because there is movement through the study area (5) and because a few males gain many of the matings (as suggested by Fig. 2).…”

mentioning

confidence: 99%

“…In both of these examples there has been a cessation of gene flow through the male and the female line, presumably attributable to behavioral factors and geographical separation of potential parasites. encompasses an area of approximately 7 km2 and is the location of a long-term population study of cuckoos by Nakamura and co-workers (4)(5)(6). In each year, between 22 and 28 adult male and 21 to 26 adult female cuckoos were resident at this site.…”

mentioning

confidence: 99%

“…Nests of the three main host species (approximate numbers of magpie, warbler, and shrike nests found per year were 25, 180, and 40, respectively) were located in the reed beds and other areas surrounding the river and were regularly checked for cuckoo eggs. Using mist nets, we captured, measured, and collected blood samples for microsatellite DNA analysis from an estimated 75 to 90% of all resident male cuckoos and 62 to 73% of all resident females (4,5). High rates of parasitism on host nests (13 to 57%) meant that we were able to collect blood samples from 16 to 56 cuckoo chicks in a given year.…”

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confidence: 99%

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Host-Race Formation in the Common Cuckoo

Marchetti

Nakamura

Gibbs

1998

Science

132

112

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The exploitation of a new host by a parasite may result in host-race formation or speciation. A brood parasitic bird, the common cuckoo, is divided into host races, each characterized by egg mimicry of different host species. Microsatellite DNA markers were used to examine cuckoo mating patterns and host usage in an area where a new host has been recently colonized. Female cuckoos show strong host preferences, but individual males mate with females that lay in the nests of different hosts. Female host specialization may lead to the evolution of sex-linked traits such as egg mimicry, even though gene flow through the male line prevents completion of the speciation process.

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“…1). Previous studies implied that common cuckoos mate multiply (1,5,13), and a recent molecular study has shown 29. E. Oldmixon, J. P. Butler, F. C. Hoppin,].…”

Section: Host-race Formation In the Common Cuckoo Karen Marchetti* Hmentioning

confidence: 99%

Section: Host-race Formation In the Common Cuckoo Karen Marchetti* Hmentioning

confidence: 99%

“…The high gene flow arises because there is movement through the study area (5) and because a few males gain many of the matings (as suggested by Fig. 2).…”

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Host-Race Formation in the Common Cuckoo

Marchetti

Nakamura

Gibbs

1998

Science

132

112

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Melanin Biosynthesis Inhibitors from the Bark of Machilus thunbergii

Chang

et al. 2003

Biological & Pharmaceutical Bulletin

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The bioassay-guided fractionation of the methylene chloride soluble portion of a methanol extract of Machilus thunbergii bark led to the isolation of four known lignans, machilin A (1), meso-monomethyl dihydroguaiaretic acid (2), nectandrin A (3) and nectandrin B (4), which exhibited potent inhibitory activity on melanin biosynthesis in cultured B-16 mouse melanoma cells (IC(50): 39.9, 15.1, 19.4 and 37.8 microM, respectively).

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Lignans from the Bark of Machilus thunbergii and Their DNA Topoisomerases I and II Inhibition and Cytotoxicity

Lee

Woo

et al. 2004

Biological & Pharmaceutical Bulletin

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DNA topoisomerases are enzymes involved in the relaxation of DNA during a number of critical cellular processes, including replication, recombination and transcription by transiently breaking one or two strands of DNA, passing a single-or double-stranded DNA through the break, and finally resealing the breaking.1-3) Currently, only a camptothecin (CPT) family of compounds as DNA topoisomerase I-directed drugs has been introduced into the clinic to date, 4,5) though many topoisomerase II-directed drugs have been in clinical use for many years.6) DNA topoisomerases have been established as important molecular targets for anticancer drugs.7) During our search for new DNA topoisomerase inhibitors from natural products by activity-guided fractionation, several solvent extracts of more than 100 Korean folk medicines were screened for their DNA topoisomerase I inhibitory activities. Among them, the CH 2 Cl 2 extract of the bark of M. thunbergii showed strong DNA topoisomerase I inhibitory activity (94.1% inhibition at 25 mg/ml), and was subjected to the isolation of compounds with DNA topoisomerase inhibitory activity from the CH 2 Cl 2 extract of the bark of M. thunbergii.The bark of M. thunbergii has been used as a folk medicine for the treatment of leg oedema, abdominal pain and abdominal distension in Korea. 11,19) and inhibitory activity on nitric oxide synthesis in activated macrophages. 16) In this study, we isolated ten lignans from the bark of the M. thunbergii, and investigated their DNA topoisomerases I and II inhibitory effects and cytotoxicity. MATERIALS AND METHODS General ProceduresOptical rotations were measured using a JASCO DIP-1000 (Tokyo, Japan) automatic digital polarimeter. The NMR spectra were recorded on a Bruker 250 MHz (DMX 250) spectrometer using Bruker's standard pulse program. Samples were dissolved in CDCl 3 -d 1 or CD 3 OD-d 4 , and chemical shifts were reported in ppm downfield from TMS. FAB-MS spectra were measured with a VG TRIO 2A mass spectrometer. Stationary phases for column chromatography (Silica gel 60, 70-230 and 270-400 mesh and Lichroprep RP-18 gel, 40-63 mm, Merck) and TLC plates (Silica-gel 60 F 254 and RP-18 F 254 , Merck) were purchased from Merck KGaA (Darmstadt, Germany). Spots were detected under UV radiation and by spraying with 10% H 2 SO 4 , followed by heating. The camptothecin (CPT) and etoposide were purchased from Sigma Chemical Co. (St. Louis, MO, U.S.A.). Supercoiled pBR 322 plasmid DNA and calf thymus topoisomerase I were purchased from MBI Fermentas, Inc. (Hanover, MD, U.S.A.). The human topoisomerase II was purchased from TopoGEN, Inc. (Columbus, OH, U.S.A.). All other chemicals and solvents were of analytical grade, and used without further purification.Plant Material The bark of M. thunbergii was purchased in September 1999 from a folk medicine market, "Yak-ryong-si" in Daegu, Republic of Korea. These materials were confirmed taxonomically by Professor Gi-Hwan Bae, of Chungnam National University, Taejeon, Republic of Korea. A voucher specimen has been de...

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O-demethylation of meso-dimethyl dihydroguaiaretic acid in spodoptera litura

Cited by 3 publications

References 0 publications

Host-Race Formation in the Common Cuckoo

Host-Race Formation in the Common Cuckoo

Melanin Biosynthesis Inhibitors from the Bark of Machilus thunbergii

Lignans from the Bark of Machilus thunbergii and Their DNA Topoisomerases I and II Inhibition and Cytotoxicity

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