Newkome-type, 1-->3 C-branched dendrons make an excellent headgroup for amphiphiles with ultralong, saturated, linear alkyl chains. Synthesis of a homologous series of five such amphiphiles from 14 to 22 carbons-RNHCONHC(CH2CH2CO2H)3, R = n-CnH2n+1, n = 14, 16, 18, 20, 22-proceeds readily. These amphiphiles are soluble in aqueous solutions of triethanolamine. Surface-tension measurements on this homologous series reveal an unusually gradual decrease in log critical micelle concentration (CMC) as the chain length increases. In fact, the tetradecyl homologue does not appear to form micelles. Further, measurements of minimal inhibitory concentration (MIC) by broth microdilution against Mycobacterium smegmatis as a function of the initial cell density provide a direct measure of the intrinsic activity (MIC0) of each homologue. The hexadecyl homologue is the most active at inhibiting growth with an MIC0 equal to 3.5 x 10-5 M, which is 100-fold below the CMC.

Sixty-two gilts were paired at breeding and assigned randomly to one of the following dietary treatments: (1) low P or (2) high P during gestation and lactation. Two sets of diets (A and B) were formulated; each set to provide a low (10 g) and high (15 g) daily P intake (equal Ca daily intake, 15 g) when fed at 1.82 and 2.27 kg daily, respectively for sets A and B. Females were fed 1.82 kg daily of set A diets during the first 11 wk of gestation, 2.27 kg daily of set B diets for the next 3 wk and 3.34 kg of the appropriate set B diets containing 20% wheat bran until farrowing, at which time the bran was gradually removed from set B diets and the feed level increased to 4 kg daily until weaning. The proportions of defluorinated phosphate and limestone were varied to provide the appropriate level of Ca and P (low and high). At approximately 5 wk before farrowing at each parity, up to 12 females from each group were used in Ca, P and N balance trials that lasted about 2 wk. Dietary P intake did not affect the apparent absorption and retention of N and Ca; 88% of the consumed N was absorbed and one-half of the absorbed was retained, and 37% of the Ca was absorbed and 94% of the absorbed was retained. Females fed the higher P intake, although excreting higher levels of P in the feces and urine, absorbed and retained a larger amount of P; but the low P-fed sows were more efficient in the retention of P when expressed as a percentage of intake or as a percentage of the absorbed P. With the exception of average total litter weight at birth that favored high P-fed sows, live, dead and total pigs at birth, average birth weight and breeding performance were not statistically different between P levels. Except for the first parity, most characteristics favored sows fed the higher P intake. Serum Ca and P levels and hair P concentration were similar between P levels. Hair Ca concentration, however, was higher for the high P-fed sows. Sows fed the higher daily P intake retained more P and there was a trend for better farrowing performance. However, breeding performance, serum Ca and P levels, hair P concentrations and Ca and N balance were similar between dietary P intakes. These results would support current National Research Council-suggested Ca and P levels for sows.

As suggested by X-ray crystal structures, homologous, long-chain alkyl dendrons with three carboxyl groups form thin films on silver oxide surfaces, which give reflection-absorption infrared spectra that show a linear increase in intensities of methylene C-H stretching absorptions.

The syntheses of (R)- and (S)-norcarnitine ethyl esters are described starting with an optimized, chiral chemical reduction of ethyl 4-chloroacetoacetate followed by azide substitution, reduction, and dimethylation. The reaction of (R)- and (S)-norcarnitine ethyl esters with 1-bromoheptadecan-2-one gives (+)- and (-)-6-[(methoxycarbonyl)methyl]-2-pentadecyl-4,4-dimethylmorpholinium bromide, respectively, which hydrolyzes to (+)- and (-)-6-(carboxylatomethyl)-2-pentadecyl-4,4-dimethylmorpholinium (hemipalmitoylcarnitinium, (+)- and (-)-HPC), respectively, upon treatment with a hydroxide resin. (+)- and (-)-HPC are reversible active-site directed inhibitors of hepatic mitochondrial CPTs. Both stereoisomers inhibit CPT I and CPT II in control and streptozotocin diabetic rat to the same extent (Imax=100%). Using intact mitochondria (CPT I), I50values for (-)-HPC and (+)-HPC were 15.5 microM and 47.5 microM, respectively. The I50 values for CPT II were 6.7 microM and 38.5 microM for (-)-HPC and (+)-HPC, respectively. The mode of inhibition was uncompetitive for CPT I with respect to acyl-CoA. The apparent K(i) for (-)-HPC is about 5 microM. These data suggest that (-)-HPC may be useful for further evaluation as an antidiabetic agent.

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