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1.
From the root bark of Erythrina burttii three isoflav-3-enes, 7,4'-dihydroxy-2'-methoxy-6-(1",1"-dimethylallyl)isoflav-3-ene (trivial name, burttinol-A), 4'-hydroxy-2'-methoxy-2",2"-dimethylpyrano[5",6":8,7]isoflav-3-ene (trivial name, burttinol-B), 7,4'-dihydroxy-2'-methoxy-8-(3",3"-dimethylallyl)isoflav-3-ene (trivial name, burttinol-C), and 2-arylbenzofuran, 6,4'-dihydroxy-2'-methoxy-5-(1",1"-dimethylallyl)-2-arylbenzofuran (trivial name, burttinol-D) were isolated. In addition, the known compounds, abyssinone V-4'-methyl ether, bidwillol A, calopocarpin, erybraedin A, erythrabyssin II, isobavachalcone, phaseollidin and phaseollin were identified. The structures were determined on the basis of spectroscopic evidence. 相似文献
2.
Ogweno Midiwo J. Yenesew A. Juma B.F. Derese S. Ayoo J.A. Aluoch A.O. Guchu S. 《Phytochemistry Reviews》2002,1(3):311-323
There are several described medicinal plants in Kenya from a flora of approximately 10,000 members. Strong cross-medical information
from the 42 ethnic groups points to the high potential of some of these species. The Myrsinaceae are well established ethno-anthelmintics
and anti-bacterials. They are harbingers of long alkyl side chain benzoquinones which clearly have a protective function from
their histochemical disposition. The main benzoquinone in the sub-family Myrsinodae is embelin while for the Maesodae it is
maesaquinone together with its 5-acetyl derivative; the distribution of these benzoquinones by their alkyl side chain length
or the presence/absence of a 6-methyl group is in accord with morphological sub-family de-limitation. The benzoquinones showed
anti-feedant, anti-microbial, phytotoxic, acaricidal, insecticidal and nematicidal activity. Many other benzoquinones of medium
and minor concentration were also isolated and characterised. Some plants belonging to the Polygonaceae which are widely used
as ethno-anthelmintics have been studied. The common anthelmintic anthraquinones were obtained from all five Rumex species
while the naphthalenic acetogenin derivative, nepodin was more selectively distributed. The leaf of Polygonum senegalense is up to 17% surface exudate; about thirteen non polar flavonoid derivatives (chalcones, dihydrochalcones, flavanones and
a flavone) have been isolated from it. From the internal aerial tissues of this plant, the major flavonoids were common flavonoids,
quercetin, kaempferol, luteolin and their glycosides. The only unique compound isolated from this plant was 2′-glucosyl-6′-hydroxy-4′-methoxydihydrochalcone
whose aglycone, uvangolatin is part of the exudate mixture. Other leaf exudate plants studied include the stomach-ache medicine,
Psiadia punctulata (Compositae) from which novel methylated flavonoids, kaurene and trachyloban diterpenes have been found.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
Leonidah K. Omosa Jacob O. Midiwo Solomon Derese Abiy Yenesew Martin G. Peter Matthias Heydenreich 《Phytochemistry letters》2010,3(4):217-220
Phytochemical investigation of the leaf surface exudate of Dodonaea angustifolia L.f. yielded two new neo-clerodane diterpenes, neo-clerodan-3,13-dien-16,15:18,19-diolide (mkapwanin) and 15-methoxy-neo-clerodan-3,13-dien-16,15:18,19-diolide (15-methoxymkapwanin). In addition, ten known compounds were identified. The structures were determined on the basis of spectroscopic evidence. This additional chemical information could contribute towards solving the taxonomical controversy that exists between Dodonaea angustifolia and Dodonaea viscosa Jacq., which are morphologically similar. 相似文献
4.
Polyketide Synthase Genes from Marine Dinoflagellates 总被引:2,自引:0,他引:2
5.
Daleep K. Arora Abiy M. Mohammed Anjaneyulu Kowluru 《Apoptosis : an international journal on programmed cell death》2013,18(1):1-8
Emerging evidence implicates novel roles for post-translational prenylation (i.e., farnesylation and geranylgeranylation) of various signaling proteins in a variety of cellular functions including hormone secretion, survival and apoptosis. In the context of cellular apoptosis, it has been shown previously that caspase-3 activation, a hallmark of mitochondrial dysregulation, promotes hydrolysis of several key cellular proteins. We report herein that exposure of insulin-secreting INS 832/13 cells or normal rat islets to etoposide leads to significant activation of caspase-3 and subsequent degradation of the common α-subunit of farnesyl/geranylgeranyl transferases (FTase/GGTase). Furthermore, the above stated signaling steps were prevented by Z-DEVD-FMK, a known inhibitor of caspase-3. In addition, treatment of cell lysates with recombinant caspase-3 also caused FTase/GGTase α-subunit degradation. Moreover, nifedipine, a calcium channel blocker, markedly attenuated etoposide-induced caspase-3 activation, FTase/GGTase α-subunit degradation in INS 832/13 cells and normal rat islets. Further, nifedipine significantly restored etoposide-induced loss in metabolic cell viability in INS 832/13 cells. Based on these findings, we conclude that etoposide induces loss in cell viability by inducing mitochondrial dysfunction, caspase-3 activation and degradation of FTase/GGTase α-subunit. Potential significance of these findings in the context of protein prenylation and β-cell survival are discussed. 相似文献
6.
Guchu SM Yenesew A Tsanuo MK Gikonyo NK Pickett JA Hooper AM Hassanali A 《Phytochemistry》2007,68(5):646-651
A pterocarpan, 1,9-dihydroxy-3-methoxy-2-methylpterocarpan (named uncinacarpan) and two isoflavanones, 5,7-dihydroxy-2',3',4'-trimethoxy-6-(3-methylbut-2-enyl)isoflavanone (named uncinanone D) and 5,4'-dihydroxy-7,2'-dimethoxy-6-methylisoflavanone (named uncinanone E), were isolated from the CH(2)Cl(2) root extract of Desmodium uncinatum (Jacq.) DC and characterised by spectroscopic methods. In addition, a rare pterocarpan edudiol and two known abietane diterpenes, 7-oxo-15-hydroxydehydroabietic acid and 7-hydroxycallitrisic acid were identified. The fraction of the root extract that was analysed induced germination of Striga hermonthica seeds, but none of the isolated compounds showed this activity. 相似文献
7.
Ivan Gumula Matthias Heydenreich Solomon Derese Isaiah O. Ndiege Abiy Yenesew 《Phytochemistry letters》2012,5(1):150-154
From the stem bark of Platycelphium voënse (Leguminosae) four new isoflavanones were isolated and characterized as (S)-5,7-dihydroxy-2′,4′-dimethoxy-3′-(3″-methylbut-2″-enyl)-isoflavanone (trivial name platyisoflavanone A), (±)-5,7,2′-trihydroxy-4′-methoxy-3′-(3″-methylbut-2″-enyl)-isoflavanone (platyisoflavanone B), 5,7-dihydroxy-4′-methoxy-2″-(2?-hydroxyisopropyl)-dihydrofurano-[4″,5″:3′,2′]-isoflavanone (platyisoflavanone C) and 5,7,2′,3″-tetrahydroxy-2″,2″-dimethyldihydropyrano-[5″,6″:3′,4′]-isoflavanone (platyisoflavanone D). In addition, the known isoflavanones, sophoraisoflavanone A and glyasperin F; the isoflavone, formononetin; two flavones, kumatakenin and isokaempferide; as well as two triterpenes, betulin and β-amyrin were identified. The structures were elucidated on the basis of spectroscopic evidence. Platyisoflavanone A showed antibacterial activity against Mycobacterium tuberculosis in the microplate alamar blue assay (MABA) with MIC = 23.7 μM, but also showed cytotoxicity (IC50 = 21.1 μM) in the vero cell test. 相似文献
8.
7a-O-methyldeguelol, a modified rotenoid with an open ring-C, from the roots of Derris trifoliata 总被引:1,自引:0,他引:1
Yenesew A Mushibe EK Induli M Derese S Midiwo JO Kabaru JM Heydenreich M Koch A Peter MG 《Phytochemistry》2005,66(6):653-657
From the acetone extract of the roots of Derris trifoliata an isoflavonoid derivative, named 7a-O-methyldeguelol, a modified rotenoid with an open ring-C, representing a new sub-class of isoflavonoids (the sub-class is here named as rotenoloid), was isolated and characterised. In addition, the known rotenoids, rotenone, deguelin and alpha-toxicarol, were identified. The structures were determined on the basis of spectroscopic evidence. Rotenone and deguelin were identified as the larvicidal principles of the acetone extract of the roots of Derris trifoliata. 相似文献
9.
Peggoty Mutai Matthias Heydenreich Grace Thoithi Grace Mugumbate Kelly Chibale Abiy Yenesew 《Phytochemistry letters》2013,6(4):671-675
Two new 3-hydroxyisoflavanones, (S)-3,4′,5-trihydroxy-2′,7-dimethoxy-3′-prenylisoflavanone (trivial name kenusanone F 7-methyl ether) and (S)-3,5-dihydroxy-2′,7-dimethoxy-2″,2″-dimethylpyrano[5″,6″:3′,4′]isoflavanone (trivial name sophoronol-7-methyl ether) along with two known compounds (dalbergin and formononetin) were isolated from the stem bark of Dalbergia melanoxylon. The structures were elucidated using spectroscopic techniques. Kenusanone F 7-methyl ether showed activity against Mycobacterium tuberculosis, whereas both of the new compounds were inactive against the malaria parasite Plasmodium falciparum at 10 μg/ml. Docking studies showed that the new compounds kenusanone F 7-methyl ether and sophoronol-7-methyl ether have high affinity for the M. tuberculosis drug target INHA. 相似文献
10.
Lee R. Machado Jennifer Bowdrey Eliford Ngaimisi Abiy Habtewold Omary Minzi Eyasu Makonnen Getnet Yimer Wondwossen Amogne Sabina Mugusi Mohammed Janabi Getachew Aderaye Ferdinand Mugusi Maria Viskaduraki Eleni Aklillu Edward J. Hollox 《PloS one》2013,8(11)
AIDS, caused by the retrovirus HIV, remains the largest cause of morbidity in sub-Saharan Africa yet almost all genetic studies have focused on cohorts from Western countries. HIV shows high co-morbidity with tuberculosis (TB), as HIV stimulates the reactivation of latent tuberculosis (TB). Recent clinical trials suggest that an effective anti-HIV response correlates with non-neutralising antibodies. Given that Fcγ receptors are critical in mediating the non-neutralising effects of antibodies, analysis of the extensive variation at Fcγ receptor genes is important. Single nucleotide variation and copy number variation (CNV) of Fcγ receptor genes affects the expression profile, activatory/inhibitory balance, and IgG affinity of the Fcγ receptor repertoire of each individual. In this study we investigated whether CNV of FCGR2C, FCGR3A and FCGR3B as well as the HNA1 allotype of FCGR3B is associated with HIV load, response to highly-active antiretroviral therapy (HAART) and co-infection with TB. We confirmed an effect of TB-co-infection status on HIV load and response to HAART, but no conclusive effect of the genetic variants we tested. We observed a small effect, in Ethiopians, of FCGR3B copy number, where deletion was more frequent in HIV-TB co-infected patients than those infected with HIV alone. 相似文献