M4L6 cages built from BODIPY- and pyrene-containing subcomponents perform multiple functions: sensing anions and amino acids, and forming a white-light emitting complex with perylene.

Scheme 1. The two-step synthesis of cube 3 via the square-planar Pt II intermediate 2 and the one-pot synthesis of 3 starting from free subcomponents and metal ions. For clarity, the chemical structure of only one of the six faces of the cube is shown.

alpha-Sarcin is a ribosome inactivating protein produced by the mould Aspergillus giganteus. The effect of this protein on eight different tumour cell lines has been studied in the absence of any agent affecting membrane permeability. The protein is cytotoxic for all the tumour cell lines considered. alpha-Sarcin modifies the cell proliferation pattern by inhibiting the protein biosynthesis of the cultured cells. No membrane damage produced by alpha-sarcin has been observed by measuring lactic dehydrogenase leakage. Alteration on the cell mitochondrial activity has not been detected upon treatment with alpha-sarcin. Differences on the extent of the protein binding to the cells have been observed by flow cytometric measurements. The kinetic analysis of the protein biosynthesis inhibition produced by alpha-sarcin reveals an alpha-sarcin concentration-dependent lag phase followed by a first order decrease of the protein synthesis rate. This parameter is dependent on the external alpha-sarcin concentration. A saturable component for the action of alpha-sarcin is also deduced from these experiments. Results are discussed in terms of the protein passage across the cell membrane as the potential rate-limiting step for the action of alpha-sarcin.

A mixture of two triamines, one diamine, 2-formylpyridine and a Zn(II) salt was found to self-sort, cleanly producing a mixture of three different tetrahedral cages. Each cage bound one of three guests selectively. These guests could be released in a specific sequence following the addition of 4-methoxyaniline, which reacted with the cages, opening each in turn and releasing its guest. The system here described thus behaved in an organized way in three distinct contexts: cage formation, guest encapsulation, and guest release. Such behavior could be used in the context of a more complex system, where released guests serve as signals to other chemical actors.

[reaction: see text] Ring opening of alpha-substituted-alpha-methoxycarbonyl-N-nosylaziridines provides a practical access to enantiopure alpha,alpha'-disubstituted beta-lactam scaffolds, novel types of ditopic reverse turn surrogates. The procedure is general, short, and high yielding and starts from handy alpha-substituted serinates and alpha-amino acid derivatives.