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Alpha-keto acid is a bifunctional organic compound containing both carboxyl and ketone groups, and widely applied in the industries of food, pharmaceutical and cosmetics. Based on the demand of eco-friendly process, safety and sustainable development, production of α-keto acids by enzymatic conversion technology has been paid more and more attention. In this article, we review the status of α-keto acids biosynthesis from three aspects: enzymatic screening, enzymatic modification and optimization of enzymatic conversion conditions. Meanwhile, we also indicate future research directions for further improving α-keto acids production.
Asunto(s)
Cetoácidos , MetabolismoRESUMEN
Objective To evaluate the efficacy and safety of short-term restriction of dietary protein intake (DPI) supplemented with α-keto acids on chronic hepatitis B patients complicated with chronic kidney diseases (CKD). Methods A prospective randomized controlled trial was carried out.Seventeen chronic hepatitis B patients with CKD were randomized to either low DPI with α-keto acid-supplemented (sLP) or low DPI (LP) group for 3 months.Low-protein diet (LPD) was individualized with total energy intake 125.52-146.44 kJ·kg-1 ·d-1,and protein intake of 0.6-0.8 g·kg-1·d-1.α-keto acid was supplied in a dosage of 0.1 g·kg-1·d-1.Nutritional indexes were recorded and other clinical indexes were measured to evaluate the efficacy and safety respectively. Results The urine protein excretion level and microalbuminuria were significantly decreased at the end of the observation period in the sLP group compared to the basal value and the LP group [24 h urine protein:baseline (4.52±1.74) g,the 1st month (3.19±1.52) g,the 2nd month (2.19±1.1) g,the 3rd month (1.64±0.77) g,P＜0.05; microalbuminyria:baseline (2855.43±248.03) mg/L,the 1st month (2157.14±218.15) mg/L,the 2nd month (1681.57±146.18) mg/L,the 3rd month (924.29±83.33) mg/L,P＜0.05].No significant difference was found in Scr and eGFR.Nutritional indexes (SGA,serume albumin) were significantly higher at the end of 3 months in the sLP group (P＜0.05).No obvious side-effect occurred. Conclusions Short-term restriction of DPI is safe,and when combined with α-keto acids,can increase serum protein and decrease urine protein excretion in chronic hepatitis B patients complicated with CKD without significant sideeffect.
RESUMEN
Objective To observe the influence of low protein diet with α-keto acid on kidney sclerosis and renin-angiotensin system in renal ablation rats. Methods Chronic renal failure rat model was established by renal ablation in 30 male SD rats,then the animals were randomly assigned to the following diet groups:normal protein group (NPD:18%casein protein),low protein group (LPD:6%casein protein) and supplemented low protein group (LK:5%casein protein+1%α-keto acids).Ten male SD sham-operated rats received 18%casein protein as control.All the rats were killed at the end of the 12th week.Pathologic changes were assessed by PAS staining.Ang II in homogenate and plasma were measured by radioimmunoassay and ELISA respectively.Immunohistochemistry and Western blotting were used to detect the protein expression of TGF-β1,renin and AT1R.Real-time PCR was used to detect the gene expression of renin and ATla,the main subtype of AT1 receptor. Results Body weight,total protein and serum albumin had not significant difference among the four groups(all P>0.05).Serum creatinine and proteinuria of nephrectomized rats were significantly higher compared to the control group (all P<0.05).Proteinuria of the LK group was lower than that of NPD and LPD groups (all P<0.05).Pathological results indicated fibrosis indices were significantly improved after LPD and LK intervention.Expressions of renin,Ang II and AT1R in LK group were significantly lower than those in NPD group (all P<0.05). Conclusions Low protein diet with α-keto acids supplement therapy exhibits renal protective effects of reducing urine protein excretion and improving renal fibrosis,which might be related to the attenuation of local renin-angiotensin system in activity nephrectomized rats.