2,4-Dichlorophenoxyacetic acid (2,4-D) is an herbicide and plant growth regulator widely applied in crop production. New multicomponent crystals of 2,4-D have been discovered by a combined virtual and experimental cocrystal...
The solubilities of penicillin sulfoxide in ethyl acetate, 4-methyl-2-pentanone, butyl acetate, and toluene from (273.15 to 332.75) K were measured with the mole fraction by a gravimetric method The solubilities in these solvents are temperature dependent. The results show that the solubility of penicillin sulfoxide in toluene is very low, so toluene is considered as one of the best solvents and used in industry. According to the results, we can see that the solubilities of penicillin sulfoxide in ethyl acetate, 4-methyl-2-pentanone, butyl acetate, and toluene can be correlated well with a semiempirical equation. IntroductionPenicillin sulfoxide is a white powder crystal, and the chemical structure is shown in Figure 1. As the precursor of 7-amino-3-desacetoxycephalosporanic acid (7-ADCA) which is an important nucleus of cephalosporin antibiotics, after range enlarged and catalytic cracked, penicillin sulfoxide was changed into 7-ADCA. 1-3 So the production of penicillin sulfoxide is crucial to the development of medicaments. Ethyl acetate, 4-methyl-2-pentanone, butyl acetate, and toluene were used in range enlargement in industry. 4 The solubilities of penicillin sulfoxide in these solvents directly affect the yield of 7-ADCA and control the cost of production. It is necessary to know the solubility of penicillin sulfoxide. In this work, the solubilities of penicillin sulfoxide in ethyl acetate, 4-methyl-2-pentanone, butyl acetate, and toluene from (273.15 to 332.75) K under atmospheric pressure were experimentally determined using a gravimetric method. 5 No similar reports have been published in the literature up to date. Experimental SectionMaterials. Penicillin sulfoxide (C 16 H 20 N 2 O 6 S, molecular weight 350.16) supplied by North China of Pharmaceutical Group Corporation Beta Co., Ltd., with a melting point of 164°C, measured by a NETZSCH DSC 204 differential scanning calorimeter, was purified by recrystallization twice. The product's mass fraction determined by Agilent 1200 HPLC was found to be higher than 99.2 %. Ethyl acetate, 4-methyl-2-pentanone, butyl acetate, and toluene (purchased from Tianjin Kewei Co. of China) were of analytical reagent grade and used without any treatment. Their mass fractions were better than 99.5 %.Apparatus and Procedure. The solubility of penicillin sulfoxide was measured by the gravimetric method. 5 The measuring principle is the same as that described in the literature. 5 There are two crystal water molecules within one penicillin sulfoxide crystal cell by single-crystal X-ray diffraction analysis, so crystal water should be removed from penicillin sulfoxide completely. After being dissolved in butyl acetate and agitated at 55°C for 0.5 h, penicillin sulfoxide was filtrated and dried in vacuo below 40°C. The solubility measuring experiments were performed in a 100 mL glass jacket vessel with water circulated from a water bath. The temperature was kept stable (fluctuates within 0.05 K) through the thermostated bath (type 501A, China). Continuous stirring of the solution ...
Here, we elucidated the structural characteristics of a polysaccharide isolated from Gardenia jasminoides Ellis (labeled as GP2a) and its immunomodulatory activity. GP2a is an acidic polysaccharide with a molecular weight of 44.8 kDa, mostly comprising galacturonic acid. Methylation analysis revealed 4-GalpA (74.8%) to be the major sugar residue in GP2a. Nuclear magnetic resonance analysis indicated that its main chain comprised →4)-α-D-GalpA-6-OMe-(1→4)-α-D-GalpA-(1→ and →4)-α-D-GalpA-6-OMe-(1→2)-α-L-Rhap-(1→, with galactan and arabinans linked to the C-4 position of →2)-α-L-Rhap-(1→ residue as branched chains. Furthermore, GP2a showed no obvious toxicity to macrophages (RAW 264.7) while enhancing cell viability in a dose- and time-dependent manner. Compared with untreated cells, nitric oxide production and secretion of cytokines, such as tumor necrosis factor-α, interferon-γ, interleukin (IL)-1β, IL-6, and granulocyte macrophage colony stimulating factor, in GP2a-treated cells significantly increased after 48 h. At 300 µg/mL GP2a concentration, there was no significant difference in the cytokine levels in GP2a- and lipopolysaccharide-treated cells (the positive control). In summary, GP2a is a pectic polysaccharide with homogalacturonan and rhamnogalacturonan-I structural regions in the main chain. Based on its immunomodulatory effects in vitro, GP2a may have potential uses in functional food and medicine.
Penicillin sulfoxide is the intermediate for the synthesis of 7-amino-3-desacetoxycephalosporanic acid which is one of the most important nucleuses of cephalosporin antibiotic. In this contribution, two crystal structures of penicillin sulfoxide (forms I and II) were determined by X-ray diffraction, and their thermotropic properties were investigated by differential scanning calorimetry (DSC). Furthermore, the transformation of form II to form I was studied quantitatively by Raman spectroscopy, and its rates at different temperatures were determined. The results indicate that penicillin sulfoxide is more stable as form I, and the temperature plays an important role in the crystal transformation.
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