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Trace amounts of poly[(R)‐3‐hydroxybutanoate] were isolated from competent Escherichia coli, spinach, bovine serum albumin, beef heart mitochondria, and aortal tissues, all sources in which it is not accumulated as storage material. Its identity was in all cases proved by 1H‐NMR spectroscopy. In some runs, the poly[(R)‐3‐hydroxybutanoate] isolated from competent E. coli also contained some 3‐hydroxyvalerate, an observation confirmed by 1H‐NMR spectroscopy and gas chromatography. The absolute configuration of the polymers isolated from E. coli and spinach was shown to be (all‐R) by gas chromatography on chiral columns.

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Phase equilibrium, glass-forming, properties and structure of the glasses in the TeO2--B203 system have been investigated. The phase diagram is a simple eutectic-like type without any compound formation. A wide region of stable phase separation has been established. A monotectic temperature at 934 K and nonvariant point at 73.6% TeO2 has been determined. The temperature dependence of the stable phase separation in the system has been studied. Some properties (density, transformation temperature, softening point, coefficient of thermal expansion, hardness, absorption in the UV and VIS region) of the tellurite borate glasses have been investigated. A structural interpretation of the glasses, on the basis of B 11 NMR spectra was undertaken and two coordination states of boron atoms have been established. A simple model of two telluriumboron-oxygen building units is presented.