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41.
From cultures of a Phoma species (strain S 298) the hitherto unknown metabolite deoxaphomine has been isolated. On the basis of the spectral data, structure 1 of the (7S, 16R, 20R)-7,20-dihydroxy-16-methyl-10-phenyl-[13]cytochalasa-6(12),13t,21t-triene-1,23-dione is assigned to deoxaphomine. This structure is confirmed by the chemical degradation of 1 , yielding the products 4 and 6 which are identical with derivatives of phomine ( 2 )((7S,16R,20R)-7,20-dihydroxy-16-methyl-10-phenyl-24-oxa-[14]cytochalasa-6(12), 13t,21t-triene-1,23-dione) and cytohalasin D ( 8 ) ((7S,16S,18R,21R)-21-acetoxy-7,18-dihydroxy-16,18-dimethyl-10-phenyl-[11]sytochalasa-6(12),13t,19t-triene-1,17-dione). Deoxaphomine ( 1 ) is a potential biogenetic precursor of the 24-oxa-[14]cytochalasans. Preliminary results of the biological activity of deoxaphomine are reported. 相似文献
42.
43.
O. Hromatka M. Knollmüller D. Binder 《Monatshefte für Chemie / Chemical Monthly》1968,99(3):1117-1123
Zusammenfassung Beim Einwirken von Perbenzoesäure auf 6-Phenyl-3,4-dihydro-1H-2,1,5-benzothiadiazocin-2,2-dioxide erhält man die 5-Oxide, die sich durch Bestrahlen mit UV-Licht in die entsprechenden Oxazirino[2,3-e][2,1,5]benzothiadiazocine umwandeln lassen.
1. Mitt. dieser Reihe:O. Hromatka, D. Binder undM. Knollmüller, Mh. Chem.99, 1062; 2. Mitt.:O. Hromatka, M. Knollmüller, D. Binder, H. Deschler undG. Schöllnhammer, Mh. Chem.99, 1111 (1968). 相似文献
The reaction of perbenzoic acid with 6-phenyl-3,4-dihydro-1H-2,1,5-benzothiadiazocine-2,2-dioxides leads to the corresponding 5-oxides, which in turn can be converted to oxazirino-[2,3-e][2,1,5]benzothiadiazocines by uv-irradiation.
1. Mitt. dieser Reihe:O. Hromatka, D. Binder undM. Knollmüller, Mh. Chem.99, 1062; 2. Mitt.:O. Hromatka, M. Knollmüller, D. Binder, H. Deschler undG. Schöllnhammer, Mh. Chem.99, 1111 (1968). 相似文献
44.
As a model for a binary alloy undergoing an unmixing phase transition, we consider a square lattice where each site can be either taken by an A atom, a B atom, or a vacancy (V), and there exists a repulsive interaction between AB nearest neighbor pairs. Starting from a random initial configuration, unmixing proceeds via random jumps of A atoms or B atoms to nearest neighbor vacant sites. In the absence of any interaction, these jumps occur at jump rates
A and
B, respectively. For a small concentration of vacancies (c
v=0.04) the dynamics of the structure factorS(k,t) and its first two momentsk
1(t),k
2
2
(t) is studied during the early stages of phase separation, for several choices of concentrationc
B of B atoms. Forc
B=0.18 also the time evolution of the cluster size distribution is studied. Apart from very early times, the mean cluster sizel(t) as well as the moments of the structure function depend on timet and the ratio of the jump rates (=
B/
A) only via a scaled timet/(). Qualitatively, the behavior is very similar to the direct exchange model containing no vacancies. Consequences for phase separation of real alloys are briefly discussed. 相似文献
45.
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49.
Zirbs R Kienberger F Hinterdorfer P Binder WH 《Langmuir : the ACS journal of surfaces and colloids》2005,21(18):8414-8421
We have developed a new concept to effect nanoparticle binding on surfaces by use of directed, specific molecular interactions. Hamilton-type receptors displaying a binding strength of approximately 10(5) M(-)(1) were covalently fixed onto self-assembled monolayers via Sharpless-type "click" reactions, thus representing an efficient method to control the densities of ligands over a range from low to complete surface coverage. Au nanoparticles covered with the matching barbituric acid receptors bound with high selectivity onto this surface by a self-assembly process mediated by multiple hydrogen bonds. The binding process was investigated with atomic force microscopy. Moderate control of particle density was achieved by controlling the receptor density on the self-assembled monolayer surface. The method opens a general approach to nanoparticle and small object binding onto patterned surfaces. 相似文献
50.
H. Binder I. Duttlinger H. Loos K. Locke A. Pfitzner H.-J. Flad A. Savin M. Kohout 《无机化学与普通化学杂志》1995,621(3):400-404
Synthesis and Vibrational Spectroscopic Investigation of [H3B? Se? Se? BH3]2? and [H3B-μ2-Se(B2H5)]? Crystal Structure and Theoretical Investigation of the Molecular Structure of [H3B-μ2-Se(B2H5)]? M2[H3B? Se? Se? BH3] 1 is produced by the reaction between elemental selenium and MBH4 (1 : 1) in triglyme (diglyme), under dehydrogenation. 1 reacts with an excess of B2H6 to give M[H3B-μ2-Se(B2H5)] 2 which is also formed in the reaction of THF · BH3 with 1 . These reactions proceed under cleavage of the Se? Se bond and hydrogen evolution. [(C6H5)4]Br reacts with Na · 2 to form [(C6H5)4P] · 2 which crystallizes in the tetragonal space group I4 (Nr. 82). An X-ray structure determination failed because of disordering of the cation and anion. 11B, 77Se NMR shifts and 1J(11B1H) coupling constants as well as IR- and Raman spectroscopic investigations convey further structural information. Structural data of 2 have been calculated by SCF methods. The anion of 2 may be viewed either as an adduct of Se with B3H8?, or as a bridge substituted selena derivative of B2H6. 相似文献