Probiotic Pediococcus pentosaceus restored gossypol-induced intestinal barrier injury by increasing propionate content in Nile tilapia

Background Intestinal barrier is a dynamic interface between the body and the ingested food components, however, dietary components or xenobiotics could compromise intestinal integrity, causing health risks to the host. Gossypol, a toxic component in cottonseed meal(CSM), caused intestinal injury in fish or other monogastric animals. It has been demonstrated that probiotics administration benefits the intestinal barrier integrity, but the efficacy of probiotics in maintaining intestinal health when the host is exposed to gossypol remains unclear. Here, a strain(YC) affiliated to Pediococcus pentosaceus was isolated from the gut of Nile tilapia(Oreochromis niloticus) and its potential to repair gossypol-induced intestinal damage was evaluated.Results A total of 270 Nile tilapia(2.20 ± 0.02 g) were allotted in 3 groups with 3 tanks each and fed with 3 diets including CON(control diet), GOS(control diet containing 300 mg/kg gossypol) and GP(control diet containing 300 mg/kg gossypol and 10^(8) colony-forming unit(CFU)/g P. pentosaceus YC), respectively. After 10 weeks, addition of P. pentosaceus YC restored growth retardation and intestinal injury induced by gossypol in Nile tilapia. Transcriptome analysis and si RNA interference experiments demonstrated that NOD-like receptors(NLR) family caspase recruitment domain(CARD) domain containing 3(Nlrc3) inhibition might promote intestinal stem cell(ISC) proliferation, as well as maintaining gut barrier integrity. 16S r RNA sequencing and gas chromatography-mass spectrometry(GC-MS) revealed that addition of P. pentosaceus YC altered the composition of gut microbiota and increased the content of propionate in fish gut. In vitro studies on propionate's function demonstrated that it suppressed nlrc3 expression and promoted wound healing in Caco-2 cell model.Conclusions The present study reveals that P. pentosaceus YC has the capacity to ameliorate intestinal barrier injury by modulating gut microbiota composition and elevating propionate level. This finding offers a promising strategy for the feed industry to incorporate cottonseed meal into fish feed formulations.

Effects of ethanol and sex on propionate metabolism evaluated via a faster ^(13)C-propionate breath test in rats

BACKGROUND Alcoholism is regarded as a risk factor for vitamin B_(12)(VB_(12))deficiency.Because V B_(12) serves as a coenzyme of methylmalonyl-CoA mutase,a key enzyme in propionate metabolism,the ^(13)C-propionate breath test(PBT)has been studied as a non-invasive diagnostic modality for VB_(12) deficiency.However,the conventional PBT requires 2 h,which is inconvenient in clinical practice.We hypothesized that a faster PBT can be used to evaluate propionate metabolism and is more easily adaptable for clinical practice.AIM To evaluate a faster PBT for assessing the effects of long-term ethanol consumption on propionate metabolism in ethanol-fed rats(ERs).METHODS ERs were obtained by replacing standard drinking water(for control rats,CRs)with 16%ethanol solution in descendants of F344/DuCrj rats.Faster PBT was performed by administering ^(13)C-propionate aqueous solution to male and female ERs and CRs by inserting a metal tubule from the mouth to the stomach;exhaled gas was collected in a bag to measure its ^(13)CO_(2)/12CO_(2) isotope ratio via infrared isotope spectrometry.Serum VB_(12) and alanine transaminase(ALT)levels were measured via chemiluminescence immunoassay and the lactate dehydrogenaseultraviolet method,respectively.We evaluated statistical differences in mean body weight,change in ^(13)CO_(2)(Δ^(13)CO_(2)‰),peakΔ^(13)CO_(2)‰,and serum VB_(12) and ALT,between males and females and between ERs and CRs using the t-test and Mann-Whitney U test for normally and non-normally distributed variables,respectively.RESULTS Males weighed significantly more than females(P<0.001);CRs weighed significantly more than ERs(P<0.008).Δ^(13)CO_(2) reached a peak(C_(max))at 20 min and 30 min in females and males,respectively,decreasing after 20-30 min without rebound in all groups.Males had significantly higher C_(max) andΔ^(13)CO_(2) at 15-45 min than females(P<0.05;for all pairs).Propionate metabolism was enhanced in male ERs relative to male CRs,whereas metabolism did not differ markedly between ERs and CRs for females.Males had higher serum VB_(12) levels than females,without prominent differences between the ER and CR groups.Male CRs had notably higher ALT levels than male ERs.Thus,chronic ethanol consumption may trigger fatty acid production via intestinal bacteria and changes in gut microbiome composition.CONCLUSION Faster PBT shows that 16%ethanol consumption promotes propionate metabolism without inducing liver injury.This PBT may be used clinically to evaluate gut flora status.

Vapor-Liquid Equilibrium Data of Carbon Dioxide＋Methyl Propionate and Carbon Dioxide＋Propyl Propionate Systems

High-pressure vapor-liquid equilibrium data for the binary systems of methyl propionate＋carbon dioxide and propyl propionate＋carbon dioxide were measured at pressure from 1.00 MPa to 12.00 MPa and temperature in the range from 313 K to 373 K. Experimental results were correlated with the Peng-Robinson equation of state with the two-parameter van der Waals mixing rule. At the same time, the Henry＇s coefficient, partial molar enthalpy change and partial molar entropy change of CO2 during dissolution at different temperature were also calculated.

Catalytic Synthesis of Geranyl Propionate

[Objective] The aim was to explore the optimal conditions for the catalytic synthesis of geranyl propionate. [Method] The synthesis of mesoporous molecular sieves Al-MCM-41 was carried out in an open-vessel. The mesoporous structure of as-synthesized Al-MCM-41 was characterized by X-ray diffraction （XRD） pattern, Fourier transform infrared （FT-IR） spectrum, NH3-Temperature Programmed Desorption （TPD）, and N2 adsorption-desorption isotherms. The catalytic performances of Al-MCM-41 for the synthesis of geranyl propionate （GP） with geraniol and propionic acid as reagents also were investigated. [Result] The as-synthesized Al-MCM-41 possesses typical hexagonal mesoporous structure with high long-range order and crystalline degree. Based on the systematic investigation of reaction time, temperature, amount ratio of reagents and regeneration of catalyst, the optimum reaction conditions were obtained with molar ratio of geraniol to propionic acid of 1.0∶1.5, reaction temperature of 120 ℃ and reaction time of 8 h. The high GP selectivity of 70.01% with geraniol conversion of 40.01% was achieved under above optimum conditions. The catalyst inactivation can be observed after five catalytic cycles. The regeneration of inactivated catalyst with high activity and selectivity can be achieved by calcination treatment to remove the carbon deposition, which covers the acid site of catalyst. [Conclusion] The optimal conditions for the synthesis of geranyl propionate were obtained.

Anti-inflammatory properties of the short-chain fatty acids acetate and propionate:A study with relevance to inflammatory bowel disease

AIM： To compare the anti-inflammatory properties of butyrate with two other SCFAs, namely acetate and propionate, which have less well-documented effects on inflammation. METHODS： The effect of SCFAs on cytokine release from human neutrophils was studied with EHSA. SCFA- dependent modulation of NF-κB reporter activity was assessed in the human colon adenocarcinoma cell line, Colo320DM. Finally, the effect of SCFAs on gene expression and cytokine release, measured with RT-PCR and ELISA, respectively, was studied in mouse colon organ cultures established from colitic mice. RESULTS： Acetate, propionate and butyrate at 30 mmol/L decreased LPS-stimulated TNFα release from neutrophils, without affecting IL-8 protein release. All SCFAs dose dependently inhibited NF-κB reporter activity in Colo320DM cells. Propionate dose-dependently suppressed IL-6 mRNA and protein release from colon organ cultures and comparative studies revealed that propionate and butyrate at 30 mmol/L caused a strong inhibition of immune-related gene expression, whereas acetate was less effective. A similar inhibition was achieved with the proteasome inhibitor MG-132, but not the p38 MAPK inhibitor SB203580. All SCFAs decreased IL-6 protein release from organ cultures. CONCLUSION： In the present study propionate and butyrate were equipotent, whereas acetate was less effective, at suppressing NF-κB reporter activity, immune-related gene expression and cytokine release in vitro. Our findings suggest that propionate and acetate, in addition to butyrate, could be useful in the treatment of inflammatory disorders, including IBD.

Qualitative and quantitative assessment of related substances in the Compound Ketoconazole and Clobetasol Propionate Cream by HPLC-TOF-MS and HPLC

Related substances in pharmaceutical formulations are associated with their safety, efficacy and stability. However, there is no overall study already published on the assessment of related substances in the Compound Ketoconazole and Clobetasol Propionate Cream. In this work, a reliable HPLC-TOF-MS qualitative method was developed for the analysis of related substances in this preparation with a quick and easy extraction procedure. Besides the active pharmaceutical ingredients, two compounds named ketoconazole impurity B′ optical isomer and ketoconazole impurity E were identified. Furthermore, a new HPLC method for qualitative and quantitative assessment on related substances and degradation products, which were found in the stability test, was established and validated. The single standard to determine multi-components method was applied in the quantitative analysis, which was an effective way for reducing cost and improving accuracy. This study can provide a creative idea for routine analysis of quality control of the Compound Ketoconazole and Clobetasol Propionate Cream.

Degradation rates and products of fluticasone propionate in alkaline solutions

The apparent degradation rate constant of fluticasone propionate(FLT) in 0.1 M NaOH:methanol=1:1 at 37 °C was previously reported to be 0.169 ± 0.003 h^(-1), and four degradation products(products 1–4) were observed in the solution. The aims of the present study were to assess the degradation rates of FLT in other alkaline solutions and clarify the chemical structures of the four degradation products in order to obtain basic data for designing an enema for inflammatory bowel disease. The apparent degradation rate constants in 0.05 M NaOH and 0.1 M NaOH:CH_3CN=1:1 were 0.472 ± 0.013 h^(-1) and 0.154 ± 0.000 h^(-1)(n=3), respectively. The chemical structures of products 1–4 in 0.1 M NaOH:methanol=1:1 were revealed by nuclear magnetic resonance(NMR)and mass spectrometry data. The chemical structure of products 2 was that the 17-position of the thioester moiety of FLT was substituted by a carboxylic acid. The degradation product in 0.1 M NaOH:CH_3CN=1:1 was found to be product 2 based on ~1H NMR data. The degradation product in 0.05 M NaOH was considered to be product 2 based on the retention time of HPLC. These results are useful for detecting the degradation products of FLT by enzymes of the intestinal bacterial flora in the large intestine after dosing FLT as an enema.

Structure and Transesterification Reaction of Methyl 3-(Phenyldihalostannyl)propionates

The title compounds, PhX2SnCHECHECO2Me （X = C1, 1a; Br, 1b; I, 1c）, readily underwent transesterification into the corresponding analogues, PhX2SnCH2CH2CO2R when reacted with an alcohol ROH. The structural features of these compounds were described, and the possible mechanism of the novel transesterification was suggested.

Synthesis and Structure of Propionate-bridged Mixed-metal Cluster Compound: MoW_2O_2 (O_2CC_2H_5)_6 (H_2O)_3 ZnBr_4·4H_2O

The heterotrinuclear cluster compound [MoW_2O_2 (O_2CC_2H_5 )_6-( H_2O)_3] ZnBr4·4H_2O was prepared by the redox reaction of Mo (CO)_6 with Na_2W_O4 in propionic anhydride. The crystal is monoclinic of space group P2/c with a =16. 334(4) , b= 9. 657(5) , c=19. 889(9) ,β= 139. 79 (5)°,V= 2026 (2) ￣3 , Z=2 , D_c=2. 30 g/cm￣3 μ(MoKa) =106. 6 cm￣(-1) ,F(000)=1176 ,final R=0. 065 and R_ω=0. 072 for 1964 reflections with I≥3σ(I). In the structure of cation [MoW_2O_2 (O_2CC_2H_5 )_6 (H_2O)_3]￣(2+) molybdenum and tungsten atoms are statistically disordered. Three metal atoms form an equilateral triangle with the distance of M-M being 2. 735.

Isobaric vapor–liquid equilibrium for ternary system of ethanol, ethyl propionate and para-xylene at 101.3 kPa

Isobaric vapor–liquid equilibrium(VLE) data for the binary system ethyl propionate(2) + para-xylene(3) and ternary system ethanol(1) + ethyl propionate(2) + para-xylene(2) at atmospheric pressure(101.3 k Pa)were obtained by a VLE modified othmer still. All the experimental data passed a point to point consistency test of Van Ness method, which verified the data reliability. The Wilson and UNIQUAC activity coefficient models were employed to correlate the binary VLE data to obtain binary interaction parameters. Based on binary interaction parameters, ternary VLE data of ethanol(1) + ethyl propionate(2) + para-xylene(3) were predicted by Wilson and UNIQUAC models, which proved that predicted values are consistent with the experimental data.Furthermore, azeotropic phenomenon between ethanol and ethyl propionate disappears when the mole ratio of para-xylene and binary system of ethanol and ethyl propionate is 1:1. Therefore, this paper convinced that para-xylene is a proper extractive additive that could be used in extractive distillation to separate the binary azeotropic system of ethanol and ethyl propionate.

Synthesis Hexadecyl 3-{4-[2-Hydroxy-3(isopropylamino)propoxy] phenyl}propionate as Potential Ligand for Liposome Targeting to Ischemic Myocardium

Novel hexadecyl 3-{4-[2-hydroxy-3(isopropylamino)propoxy]phenyl}propionate(HPP)was synthesized and its effect on delivery of liposomes into cultured cardiomyocytes was examined.The structure of HPP was characterized by IH NMR,1R and MS.The amount of cardiomyocytes uptake of HPP-liposome was 3.9-fold higher than plain-liposome,and the increase was 6.2-fold when hypoxia happens.It indicated that HPP was a potential ligand for liposome targeting to ischemic myocardium.

SINGLE-ION CONDUCTIVITY IN POLY (LITHIUM PROPIONATE METHYL SILOXANE)

Poly(lithium propionate methyl siloxane )as a single-ion carrier source was synthesized. The crosslinked film showed lower lithium ionic conductivity at room temperature (about 10^(-10) S/cm). However,the lithium ionic conductivity was obviously increased by blending with high polar polymers such as polyethylene oxide, poly (methylsiloxane - co- ethylene oxide) and poly (methylsiloxane- g- ethylene oxide). In the blend system a high conductivity of 10^(-7)-10^(-5) Scm^(-1) at room temperature was obtained and the single-ion conductivity was deeply influenced by the content of the poly (lithium propionate methyl siioxane). The dc ionic conductivity of the flexible crosslinked films is more stable over time.

Clinical Evaluation of an Oral Electrolyte Solution Formulated Based on Strong Ion Difference (SID) and Using Propionate as the Organic Anion in the Treatment of Neonatal Diarrheic Calves with Strong Ion Acidosis

Background: It is postulated that the concentrations of the major strong ions (Na, K, and Cl) in oral electrolyte solutions play a major role in clinical efficacy of these solutions for rehydration and corrections of metabolic acid base derangements. Objectives: The purpose of this study was to test prospectively the efficacy of an OES (OESexp) formulated based on concentration of strong ion difference (SID) and propionate in a group of calves with naturally occurring neonatal diarrhea and clinically detectable dehydration and acid base abnormalities. Animals: Ten client owned calves of varying breeds, 2 - 22 days old, presented to a veterinary teaching hospital with a history of naturally occurring acute undifferentiated diarrhea, progressive depression and dehydration for treatment. Methods: Clinical and laboratory parameters were measured pre and post two oral electrolyte treatments to assess efficacy of the experimental OES to correct clinical and clinico pathological parameters. For the clinical trial the calves served as their own controls. For control of safety of medication 4 normal calves were force fed 4 L of OESexp and followed over a 24 hour period. Results: All calves had severe diarrhea and metabolic acidosis. The metabolic acidosis observed in the plasma of these calves and reflected by pH, HCO3- SID and base deficit was corrected significantly towards reference ranges (p < 0.05) with two 2 L feedings 12 hours apart. Dehydration was significantly corrected and all calves were discharged 1 - 3 days post admission. Conclusion and Clinical Importance: The use of SID is a valid approach when formulating oral electrolytes solutions for use in calves with acute diarrhea and metabolic derangement. Sodium propionate is valid substitute for commonly used sodium base equivalents in North America in oral electrolyte solutions.

Effects of Propionate on Streptolydigin Production and Carbon Flux Distribution in Streptomyces lydicus AS 4.2501

To achieve higher antibiotic streptolydigin productivity through metabolic regulation, propionate was fed during the fermentation of Streptomyces lydicus AS 4.2501. The effects of propionate feeding on streptolydigin production and intracellular fluxes were investigated. The highest streptolydigin production yield of 95.10mg·L-1 was obtained when 2mmol·L-1 of sodium propionate was added at 60h of cultivation into shake-flask culture. This yield is 23.06% higher when compared to that of a batch culture without propionate supplementation. It was also found that when propionate was added, much more organic acids were excreted. Metabolic flux analysis was per-formed and it demonstrated that the carbon fluxes of the pentose phosphate pathway and the anaplerotic reaction were significantly increased after propionate feeding. The carbon flux from pyruvate to acetyl-CoA was determined to be 24.7, which was 12.27% higher than that in the batch culture. This study indicated that the glu-cose-6-phosphate and pyruvate nodes were potential bottlenecks for increasing streptolydigin productivity. Potential targets and strategies that could be manipulated through genetic and process engineering to increase the production of streptolydigin were also suggested.

Studies on the Stability of Corticosteroids: Degradation of Clobetasol Propionate, Desonide and Hydrocortisone in Topical Formulations by HPLC and UPLC-MS/MS

Corticosteroids are the most widely used class of anti-inflammatory medications in the pharmaceutical industry. There are several pharmaceutical dosage forms available using different corticosteroids. Topical steroids of varying potencies are available in creams, ointments, solutions and other vehicles. Chemical instability and drug degradation are the key quality concerns for these topical dosage forms. Nature of the dosage forms, excipient quality, product composition, and process optimization are some of the common factors which affect the stability of corticosteroids. This article describes drug degradation behavior of three different corticosteroids in different topical dosage forms. Drug degradation patterns of Hydrocortisone, Clobetasol propionate and Desonide formulations observed in stability studies of respective finished drug products under ICH recommended storage conditions were investigated. HPLC, UPLC-MS/MS methods were developed for the separation and characterization of impurities. The structural elucidation of the unknown impurities observed for these steroids and mechanistic consideration of potential degradation pathways has been discussed. Detailed discussion on the analytical methodologies is included as well.

Effect of Chromium Propionate Substituting 25% Rumen-protected Choline on Production Performance and Blood Indicators of Perinatal Dairy Cows

The object of this study was to investigate the effects of chromium propionate replacing 25%rumen-protected choline(RPC)on production performance and blood indicators of perinatal dairy cows.According to the principle of ensuring that chromium propionate and RPC were fed 14 days prepartum,27 healthy Holstein cows(age,parity,lactation volume,body condition and expectancy were similar)were randomly divided into three groups(GroupsⅠ,ⅡandⅢ),with nine cows in each group.Cows in GroupⅠwere fed basal diets;cows in GroupⅡwere fed the same basal diets with 10 g•d-1 RPC per cow;and cows in GroupⅢwere fed the same basal diets,but 7.5 g RPC and 2.5 g chromium propionate(4 mg chromium)per cow.The results showed that dry matter intake(DMI)of prepartum in GroupsⅡandⅢwas significantly increased(P<0.05),compared with GroupⅠ;however,there was no significant difference between GroupsⅡandⅢ(P>0.05).The milk fat content in GroupⅢwas significantly higher than that in GroupⅠon the 7th day of postpartum(P<0.05).The urea nitrogen content in GroupsⅡandⅢsignificantly lower than that in GroupⅠon the 21st day of postpartum(P<0.05),but there were no significant difference between GroupsⅡandⅢ(P>0.05).The somatic cell counts in GroupⅢwere significantly lower than those in GroupsⅠandⅡon the 14th and 21st days of postpartum(P<0.05).The contents of the total cholesterol in GroupⅢdecreased significantly compared to GroupⅡon the 7th day of prepartum,on the day of calving and the 7th day of postpartum(P<0.05).The concentration of high-density lipoprotein(HDL)in GroupⅢwas significantly higher than that in GroupⅡon the 7th day of prepartum,on the day of calving and the 7th day of postpartum(P<0.05).On the 7th day of postpartum the concentration of insulin in GroupⅢwas obviously higher than that in GroupⅡ(P<0.05).In summary,replacing 25%of rumen-protected choline with chromium propionate reduced production costs and improved dairy farming benefits.

Treatment of Localized Vitiligo with 1% Pimecrolimus Cream versus 0.05% Clobetasol Propionate Cream—Single, Blinded, Comparative Therapeutic Trial

Background: Calcineurin inhibitors like tacrolimus and pimecrolimus are new modality of treatment of localized vitiligo. Objective: To compare the effectiveness and side effects of 1% pimecrolimus cream in comparison with 0.05% clobetasol propionate cream as a treatment of localized type of vitiligo. Patients and Methods: Fifty two patients with localized vitiligo were included in this single, blind, comparative therapeutic trial. Full history and examination for each patient was done. Wood’s light was used when needed to confirm the diagnosis. Thirty (57.7%) were females and 22 (42.3%) males, female to male ratio of 1.36:1. Their ages ranged between 3 - 40 (13.15 ± 7.9) years, while disease duration ranged from 6 - 84 (29.62 ± 20.56) months. Total numbers of lesions were 114 lesions with a mean of 2.2 lesions per patient. The surface area of the lesions ranged between 1 - 31 (7.15 ± 6.98) cm2. Vitiliginous patches were most commonly located on face 48 (42.1%) lesions, and lower limbs 35 (30.7%) lesions. Patients were divided in to two groups according to the type of therapeutic modality.?Group?A?consisted of 25 patients (52 lesions) receiving 1% pimecrolimus cream and?Group?B?27 patients (62 lesions) treated with 0.05% clobetasol propionate cream, both used twice daily. The amount of cream per area was applied according to rule of fingertip unit. Measuring the surface area of the lesions and calculating the reduction rate were done every month till the end of the 6th?month. Then patients were asked to stop the use of medication to be re-evaluated again after 3 months without any treatment and to record any local or systemic side effects. Results: After 6 months of treatment there was 79.67% reduction in the surface area of lesions in?Group?A, while inGroup?B?there was 82.59% reduction in the surface area with no statistically significant difference between the two groups. The reduction rate was early as there was statistically significant reduction for both groups after one month of treatment (p value < 0.01). The reduction rates for facial lesions were more than other parts of the body. There was no significant relapse after 3 months of stopping treatment for both groups. Side effects were minimal and tolerable. Conclusions: Topical 1% pimecrolimus is as effective as clobetasol propionate in treatment of localized vitiligo affecting less than 5% of the body surface area but pimecrolimus was more preferred as the side effects of topical steroid could be avoided.

A Study on the Mechanism Regulating Acetate to Propionate Ratio in Rumen Fermentation by Dietary Carbohydrate Type

The research direction of our team is nutrition and physiology of ruminants, including dietary nutrition metabolism and rumen microorganisms. Previous research has shown that ruminal acetate-to-propionate ratio is related to diet utilization efficiency. At present, it is believed that the main factors affecting the ruminal acetate-to-propionate ratio are the degradation rate of the diet and the rumen microbial structure, but the main mechanism is unclear. This study found that the effect of ruminal acetate-to-propionate ratio was not affected by the concentration of the fermentation substrate, but was affected by the structure of the rumen microbiota. We believe that changes in the rumen microflora structure are the main mechanism for regulating the ruminal acetate-to-propionate ratio. This will help people to further understand the rumen physiology, thereby gradually improving feed conversion efficiency and reducing production costs. Abstract: In order to explore the mechanism by which diet regulates the acetate-to-propionate molar ratio (A: P ratio), we compared the effect on rumen fermentation parameters and the microbiome by altering the ratio of dietary concentrates to roughage ratio and calcium pyruvate infusion. The test animals were Laoshan dairy goats, and were fed continuously through an automatic feeder. The test groups were fed a base diet of low concentrates, and intraruminally infused with calcium pyruvate at two concentrations. The infusion concentrations were derived from the difference in the rate of carbohydrate degradation of the high and low concentrate diets, and they were artificially set such that the high concentration infusion group was infused with twice the concentration as the low concentration infusion group. The control groups were fed high concentrate (6:4) and low concentrate (3:7) diets, respectively. The following results were obtained by measuring rumen fermentation parameters and microbial composition: the rumen A: P ratio was significantly lower in the high-concentrate diet group than in the low concentrate diet group (P < 0.05). Infusion of low concentration calcium pyruvate had no significant effect on rumen A: P ratio (P > 0.05), while infusion of high concentration calcium pyruvate significantly increased the rumen A: P ratio (P < 0.05). Relative to goats fed the low concentrate diet, those fed the high concentrate diet had a greater abundance of microbes related to propionate production and a reduced abundance of microbes related to fiber degradation. Infusion of pyruvate had no significant effect on rumen microbial structure. The above results indicate that increasing the concentration of the fermentation substrate without affecting the composition of the microflora does not reduce the A: P ratio. Microbiological results showed that the A: P ratio was more closely related to the rumen microflora structure. Therefore, it is believed that rumen microflora structure is the main mechanism regulating A: P ratio in rumen fermentation.

NUCLEAR MAGNETIC RESONANCE STUDIES OF METAL COMPLEXES WITH ETHYLENEDIAMINE-N,N′-DIACETATE-N,N′-DI-β-PROPIONATE

The complexes of metals(Mg,Ca,Sr,Ba,La,Y and Lu)with ethylenediamine-N,N′-diacetate-N, N′-di-β-propionate have been studied by proton nuclear magnetic resonance(PMR).The interesting quartet spectral pattern of acetate protons and multiplet spectral pattern of protons of propionate groups for the complexes of metal ions of high charge density have been observed.The results show that the chemical bond for these complexes is predominantly ionic and the lability of metal-nitrogen bond as well as metal- oxygen bond decreases with increasing charge density of cations.

Crystal Structure of Methyl 3- (2-chlorophenyl )-3- (5, 5-dimethyl-3-hydroxy-2-cyclohexene- 1-one-2-yl) propionate

The title compound C18H21ClO4 was synthesized by the reaction of 2-chlorobenzaldehyde, 5, 5-dimethyl-1, 3-cycfohexanedione and isopropylidene malonatein methanol catalyzed by KF-Al2O3 It crystallized in the monoclinic system, spacegroup P21/c, with a = 7. 587(2), b = 11. 736(3), c = 19. 120(7) A, β =101. 30°, V=1669.5(9) A 3, Dc= 1. 340 g/cm3, Z= 4, Mr= 336. 81, A= 0. 71069A, μ（MoKa) =2. 46 cm-1, F(000) = 712. The structure was refined to R=0. 034,Rw=0. 042 for 1468 observed refiections (I>3(I) ). X-ray analysis reveals that thedihedral angle between plane I[C(12)~C(17), Cl] and plane 2[O(1), O(2), C(1),C(2), C(3)] is 66. 98° and the C(11) atom exhibits a distorted tetrahedral configuration. The crystal structure shows that there is a conjugated enol form in the molecule.