A number of (aminoalkyl)-l,2-closo-dodecaboranes have been synthcsized to provide arborants with a functional group for covalent incorporation into structures of potential use in the treatment of cancer by boron neutron capture therapy (BNCT). acetylenes reacted with decaborane to give the corresponding carboranes; removal of the phthalimido group under mild conditions using sodium borohydride in 2-propanol furnished the (aminoalky1)carborancs which were isolated as their hydrochloride salts. An alternative approach involved the conversion of an (iodoalky1)or a ((tosy1oxy)alkyl)carborane to the azido derivative which gave the amine on hydrogenation. An effective way of attaching a carborane moiety to thiouracil, which is selectively taken up in melanoma cells, is illustrated by the acylation of two of these amines with thiouracil-5-carboxylic acid.
Ten new N-(2-benzimidazolylmethyl)iminodiacetic acids (BIMIDA)* have been synthesized from
the corresponding o-phenylenediamines
via intermediate 2-chloromethyl and 2-aminomethyl benzimid-
azoles as ligands for 99mTc. Anomalies associated with the synthesis
of the iodo-substituted compound are described.
The presence in " lignum vitae," the heartwood of Gzcaiacuna oficinale L., of at least nine lignans has been demonstrated by the isolation of their ethers from the methylation and ethylation products of a light-petroleum extract. I n addition to guaiaretic acid and its dihydro-compound, dehydroguaiaretic acid and two new tetrahydro-derivatives, guaiscin and isoguaiacin, have been found.The accompanying dimethoxydihydric phenol, furoguaiacin, and its monomethyl ether afford examples of the unusual furano-lignans. The occurrence of two optically inactive tetrahydrofurans, tetrahydrofuroguaiacin-A and -B, was also established and there is some evidence of a tetrahydromethylfuroguaiscin.THE hardwood, Guaiacum oficinale, which is found in the West Indies and Central America, and to a lesser extent G. sanctuw, are important as the source of the heavy durable commercial timber " lignum vitae." The name recalls fomer medicinal applications of the resin obtained from it by heat or by extraction with alcohol. Guaiacum resin constitutes some 18-25% of the wood and has been the subject of many investigations since the early nineteenth century. An alcoholic solution of the extract gives a royal blue colour in air and this has been used as a sensitive test for oxidising agents, including oxidases.
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