IntroductionThe bacterial copolyester of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) has attracted industrial attention as a possible candidate for large-scale biotechnological production, since the copolyester is an environmentally degradable thermoplastic'). The copolyester has been produced from propionic acid in Alcaligenes eutrophus, and the range of compositions has been shown to vary from 0 to 47 mol-Vo 3HVRecently, we have found that copolyesters with a wide range of compositions up to 90 mol-qo of 3HV units are produced in A . eutrophus by using pentanoic acid as carbon source4). This communication reports the biosynthesis of an interesting terpolyester of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and Shydroxyvalerate (5HV) in A . eutrophus from 5-chloropentanoic and pentanoic acids. Experimental partA. eutrophus (NCIB 11599) was first grown at 30°C in a nutrient-rich medium (100 cm3) containing 1,0 g of yeast extract, 1,0 g of polypeptone, 0,5 g of meat extract, and 0,5 g of (NH&S04. The cells were harvested after 24 h and washed with water. Under these culture conditions an accumulation of polyesters in the cells was not observed. To promote polyester synthesis, about 0,4 g quantities of the washed cells were transferred into a nitrogen-free mediums) containing 5-chloropentanoic acid (ClCH2CH2CH2CH2COOH) and pentanoic acid (CH,CH2CH2CH2COOH). The cells were cultivated in this medium (100 cm3, pH = 7 3 ) for 48 h at 30 "C, harvested by centrifugation, washed with acetone, and finally dried under vacuum at room temperature. Polyesters were extracted from the dried cells with hot chloroform in a Soxhlet apparatus and purified by reprecipitation with hexane.The ' H NMR spectra of polyester samples were recorded on a JEOL GX-500 spectrometer operating at 500 MHz, using a CDCl, solution of polyester (5 mg/cm3). The spectra were obtained at 27OC, 45 pulse ( 3 3 ps), 6,O s pulse repetition, 7000 Hz spectral width, 32K data points, and 128 accumulations. The I3C NMR spectra of polyesters were recorded on a JEOL FX-100 spectrometer operating at 25 MHz, using a CDCl, solution of polyester (50 mg/cm3). The spectra were obtained at 27 "C, 45 O pulse (8,5 ps), 5,O s pulse repetition, 5000 Hz spectral width, 8 K data points, and 10000 accumulations. \ 0173-2803/87/$01 .OO8 h) Tab. 1. Biosynthesis of terpolyesters of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 5-hydroxyvalerate (5HV) in Alculigenes eutrophus at 3OoC Sample Wt. of carbon sourcea) in g Wt. of dry Polyester Polyester compositionc) in mol-yo [tll d, cells in g contentb)
Copolyesters of 3-hydroxybutyric acid (HB) and 3-hydroxyvaleric acid (HV), P(HB-co-HV), were isolated from Alculigenes eutrophus and characterized by solution NMR, solid-state I3C CP/MAS NMR, and differential scanning calorimetry. The I3C CP/MAS NMR analysis was compatible with that of a random copolyester of oxy-(1 -methyl-3-oxotrimethylene) (B) and oxy-(l-ethyl-3-oxotrimethylene) (V) units which adopts a regular conformation of a 2, -helix in the solid state throughout a wide range of compositions varying from 0 to 90 mol-Vo V units.The chain dynamics of P(HB-co-HV) in chloroform was studied by analysis of the I3C and 'H NMR spectra. The carbon-13 spin-lattice relaxation times (T,) and nuclear Overhauser enhancements WOE) indicated that the copolyester molecules in chloroform are not rigid but rather flexible. The conformational preferences of the copolyester molecules were determined by analysis of the H NMR spectra.
A generally recognized concept dictates that surgical intervention for non-parasitic cysts of the liver is mostly palliative such as aspiration of the content, suture and closure, internal or external drainage, marsupialization, and unroofing of the cyst, while total excision of the entire cyst, which sometimes necessitates hepatic resection, is not usually recommended.3, 6, 9 The results of these lesser procedures have been acceptable, favoring those conservative procedures. This paper presents three cases with carcinoma arising in the cysts of the liver. Review of the present cases with five comparable cases appearing in the literature revealed that young female population and left lobe of the liver are frequently involved. Hence the general trend for palliative procedures should be reassessed. Possible malignancy should be considered when a patient belongs to this category, the cystic content is not clear, or the cystic wall presents irregular texture with nodules. The carcinomatous changes would have been of higher incidence than reported if the entire cysts had been more carefully examined.
IntroductionThe bacterial copolyester of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) has attracted industrial attention as a possible candidate for large-scale biotechnological production, since the copolyester is an environmentally degradable thermoplastic'). The copolyester has been produced from propionic acid in Alcaligenes eutrophus, and the range of compositions has been shown to vary from 0 to 47 mol-Vo 3HVRecently, we have found that copolyesters with a wide range of compositions up to 90 mol-qo of 3HV units are produced in A . eutrophus by using pentanoic acid as carbon source4). This communication reports the biosynthesis of an interesting terpolyester of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and Shydroxyvalerate (5HV) in A . eutrophus from 5-chloropentanoic and pentanoic acids. Experimental partA. eutrophus (NCIB 11599) was first grown at 30°C in a nutrient-rich medium (100 cm3) containing 1,0 g of yeast extract, 1,0 g of polypeptone, 0,5 g of meat extract, and 0,5 g of (NH&S04. The cells were harvested after 24 h and washed with water. Under these culture conditions an accumulation of polyesters in the cells was not observed. To promote polyester synthesis, about 0,4 g quantities of the washed cells were transferred into a nitrogen-free mediums) containing 5-chloropentanoic acid (ClCH2CH2CH2CH2COOH) and pentanoic acid (CH,CH2CH2CH2COOH). The cells were cultivated in this medium (100 cm3, pH = 7 3 ) for 48 h at 30 "C, harvested by centrifugation, washed with acetone, and finally dried under vacuum at room temperature. Polyesters were extracted from the dried cells with hot chloroform in a Soxhlet apparatus and purified by reprecipitation with hexane.The ' H NMR spectra of polyester samples were recorded on a JEOL GX-500 spectrometer operating at 500 MHz, using a CDCl, solution of polyester (5 mg/cm3). The spectra were obtained at 27OC, 45 pulse ( 3 3 ps), 6,O s pulse repetition, 7000 Hz spectral width, 32K data points, and 128 accumulations. The I3C NMR spectra of polyesters were recorded on a JEOL FX-100 spectrometer operating at 25 MHz, using a CDCl, solution of polyester (50 mg/cm3). The spectra were obtained at 27 "C, 45 O pulse (8,5 ps), 5,O s pulse repetition, 5000 Hz spectral width, 8 K data points, and 10000 accumulations. \ 0173-2803/87/$01 .OO8 h) Tab. 1. Biosynthesis of terpolyesters of 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), and 5-hydroxyvalerate (5HV) in Alculigenes eutrophus at 3OoC Sample Wt. of carbon sourcea) in g Wt. of dry Polyester Polyester compositionc) in mol-yo [tll d, cells in g contentb)
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