A-Amylase inhibitory activity

Alam et al. (2001) studied the inhibitory action of CNBR fragments of the RATI on amylase 2 purified from porcine pancreas and reported that the fragment comprising the first 10 amino acids of the N-terminal segment inhibited amylase competitively. NH2-Ser-Val-Gly-Thr-Ser-Cys-Ile-Pro-Gly-OH was most effective. A serine to alanine transformation diminished the inhibitory effect. Blocking the N-terminus abolished the a-amylase inhibitory activity. It may be presumed that the abolition of the a-amylase inhibitory activity with 2,4,6-trinitrobenzenesulfonic acid as observed by Shivraj and Pattabhiraman (1981) may have been due to its interaction with cysteine. Figure 6.9 shows a representation of this ragi protein with its ability to bind both a-amylase and trypsin with its two arms. 

Lee, S. H., Li, Y., Karadeniz, F., Kim, M. M., and Kim, S. (2009). a-Glucosidase and a-amylase inhibitory activities of phloroglucinal derivatives from edible marine brown alga, Ecklonia cava.. Sci. Food Agric. 89,1552-1558. 

Rhodiola species have been extensively studied as an adaptogen with health promoting effects and recent studies have indicated the potential of Rhodiola rosea and Rhodiola crenulata for type 2 diabetes management due to high a-glucosidase and a-amylase inhibitory activity of their phenolic extracts (Kwon et al 2006). A study was performed with... 

Other activities reported for roselle include hypotipidemic, analgesic/anti-inflammatory, and a-amylase inhibitory activities. ... 

A novel 13-membered ring thiocyclitol (214), isolated from Salacia reticulata Wight (family Hippocrateaceae), showed promising a-glucosidase inhibitory activity (IC50 maltase, 0.227 /tM sucrase, 0.186 //M isomaltase, 0.099 however, it did not inhibit a-amylase from porcine pan-... 

FIGURE 4.6. a-Amylase and a- ucosidase inhibitory activity during Kefir culture-mediated soy milk fermentation supplemented with RhorSola extracts (Kwon et al. 2006). 

The trehazolin analogues d-403, d-407, l-407, and 412 were subjected to bioassay for trehalase-inhibitory activity. They were found to completely lack activity against a-amylase, /i-D-glucosidase, a-D-mannosidase, maltase, and sucrase.103... 

An ABA analog with a fluorescent group at C-4, 6, was synthesized in two steps from ABA by Asami et al. [27]. This analog exhibited the ABA activity in an inhibitory assay of a-amylase induction in aleurone protoplasts of barley, although it required a 30-fold higher concentration than ABA. Kohler et al. reported C-4 biotinylated ABA (7), which showed 1/10 -1/100 the activity of ABA [28]. 

The methanol extract of Sophora flavescens showed potent glycosidase inhibitory activity. Active components were identified as well-known flavonoid antioxidants including kurarinol (3), maackian (6), isoxanthohumol (7), kuraridin (8), sophoraflavanone G (10), 2/-methoxykurarinone (23), kushenol A (26), 8-prenylkaempferol (63), and (-)-kurarinone (68). All of the flavonoids were effective inhibitors of a-glucosidase and /(-amylase. Interestingly, la-... 

Inhibitory activity against a-amylase by flavonoids and anthocyanins has been reported (39). Herbs used in Nigerian traditional medicine for the treatment of diabetes mellitus are known to contain phenol compounds especially the flavonoid quercetin and the mechanism of their antidiadetic activity may be brought about by their amylase inhibiting activity and the antioxidant activity of the phenolic compounds. 

Cycas rumphii Miq. (leaves) Amentoflavone (1). Amentoflavone is an inhibitor of phospholipase C yl, an irreversible inhibitor of lymphocjde proliferation, and an inhibitor of cjdosolic phospholipase A2 (CPLA2) activity in the epidermis. It has shown inhibitory activity against a-glucosidase (EC 3.2.1.20) and a-amylase (EC 3.2.1.1). Uddin et al., 2004[447]. 

Product Inhibition. In most microbiological and biochemical systems accumulation of end products exercises an inhibitory effect on the rate of the forward reaction. Stimulation by end product is thermodynamically improbable. One of the major products of hydrolysis of cellulose is cellobiose. There is a stimulation by cellobiose of Cx activity of Streptomyces spp. filtrates only when the substrate is solubilized by the introduction of various substituents—e.g., CMC, hydroxycellulose, cellulose acetate, etc. Stimulation is absent when unsubstituted cellulose is used (14). On the other hand, product inhibition is common. Cellobiose inhibits the hydrolysis of cellulose by filtrates of most of the 36 organisms tested. This action of cellobiose is believed to be that of an end product inhibiting an enzymatic hydrolysis in much the same manner that maltose inhibits hydrolysis of starch by a-amylase. The inhibitory effect of products varies with the organism from which the cellulase is derived. Thus, lactose is a very good inhibitor of the enzyme from... 

Abscisic acid (ABA) 3-1 was originally detected because of its growth inhibitory properties. It is now known to play an important role in the control of a-amylase synthesis, and regulation of stomatal aperture during water stress. Phaseic acid (PA) 3-3 is an important metabolite of ABA. Over a hundred derivatives of ABA are known, activity correlations have been reviewed, and the difficulty of drawing firm conclusions due to differences in uptake, metabolism and sequestration between the different molecules assayed has been discussed [16-20]. In many correlations, racemates have been used, and it is possible that each enantiomer may be active, have a different type of activity, and/or interfere with the action of the other enantiomer. 

Recently, a semisynthetic deoxynorjirimycin derivative Bay o 1248 (20), which is absorbed from the intestine and does not produce carbohydrate malabsorption, was reported as a potent glucosidase inhibitor exhibiting strong sucrase and maltase inhibitory activity and no amylase inhibition. Administration of which has a longer duration of action than acarbose, reduces food intake, body weight gain and epididymal fat pad weight in rats. ... 

The nutritional significance of the a-amylase inhibitors is largely unknown. It is known that low levels of inhibitory activity can be detected in regularly cooked food products. When red kidney bean a-amylase inhibitor, free of protease inhibitors and hemagglutinins, was fed to rats in a casein diet at the levels of... 

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