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71.
Ramavatar Meena Kamalesh Prasad M. Ganesan A. K. Siddhanta 《Journal of applied phycology》2008,20(4):397-402
Gracilaria edulis, G. crassa, G. foliifera, and G. corticata are naturally occurring agarophytes of Indian waters. These agarophytes were evaluated for their agar contents using an improved
process recently reported by us (US Patent 2005/0267296A1). The effect of different concentrations of NaOH in the alkali treatment
was studied for optimizing the extraction conditions. These Gracilaria species of Indian waters produced agars, both native and alkali treated, with different properties confirming the heterogeneity
of the agar polymers in this genera, as one would expect. Among these, G. edulis and G. crassa produced agar polymers having high gel strengths of 490 ± 8.16 and 800 ± 15.4 g cm−2, respectively, with 8% NaOH treatment as opposed the low gel strength agars that have been reported in the literature to
date. 相似文献
72.
Protective role of Apigenin on the status of lipid peroxidation and antioxidant defense against hepatocarcinogenesis in Wistar albino rats. 总被引:4,自引:0,他引:4
J Prince Vijeya Singh K Selvendiran S Mumtaz Banu R Padmavathi D Sakthisekaran 《Phytomedicine》2004,11(4):309-314
Apigenin, a dietary plant derived flavone subclass of flavonoid is expected to play a role in cancer chemoprevention and cancer chemotherapy. Here we designed our experiment to establish whether treatment of apigenin (25 mg/kg body weight) for 14 consecutive days to (N-nitrosodiethylamine) DEN induced (200 mg/kg body weight; by single ip. injection) and phenobarbital promoted (0.05% through drinking water for 14 successive weeks) rats provide protection against the oxidative stress caused by the carcinogen. The level of lipid peroxidation (LPO) markedly increased in carcinogen administered animals, which was brought back to near normal by apigenin treatment. In contrast the activities/levels of the antioxidant status both in liver and kidney were decreased in carcinogen administered animals, which was recouped back to near normal upon apigenin administration. From our findings we concluded that apigenin prevents LPO and protects antioxidant system in DEN induced and phenobarbital promoted hepatocellular carcinogenesis. 相似文献
73.
Balasubramanian Ganesan Kimberly Seefeldt Bart C. Weimer 《Applied microbiology》2004,70(11):6385-6393
Low concentrations of branched-chain fatty acids, such as isobutyric and isovaleric acids, develop during the ripening of hard cheeses and contribute to the beneficial flavor profile. Catabolism of amino acids, such as branched-chain amino acids, by bacteria via aminotransferase reactions and α-keto acids is one mechanism to generate these flavorful compounds; however, metabolism of α-keto acids to flavor-associated compounds is controversial. The objective of this study was to determine the ability of Brevibacterium linens BL2 to produce fatty acids from amino acids and α-keto acids and determine the occurrence of the likely genes in the draft genome sequence. BL2 catabolized amino acids to fatty acids only under carbohydrate starvation conditions. The primary fatty acid end products from leucine were isovaleric acid, acetic acid, and propionic acid. In contrast, logarithmic-phase cells of BL2 produced fatty acids from α-keto acids only. BL2 also converted α-keto acids to branched-chain fatty acids after carbohydrate starvation was achieved. At least 100 genes are potentially involved in five different metabolic pathways. The genome of B. linens ATCC 9174 contained these genes for production and degradation of fatty acids. These data indicate that brevibacteria have the ability to produce fatty acids from amino and α-keto acids and that carbon metabolism is important in regulating this event. 相似文献
74.
Cloning and characterization of thermotolerant xylitol dehydrogenases from yeast Pichia angusta 总被引:1,自引:0,他引:1
Dipanwita Biswas Manish Datt Kaliannan Ganesan Alok K. Mondal 《Applied microbiology and biotechnology》2010,88(6):1311-1320
Pichia angusta (syn. Hansenula polymorpha) represents one of the rare yeast that can grow and ferment both xylose and glucose at higher temperature (50°C). However,
little is known about the enzymes involved in xylose utilization from this species. Previous studies indicated the presence
of one xylose reductase and two xylitol dehydrogenase genes in P. angusta. In this study, we have expressed both xylitol dehydrogenases (PaXdh1p and PaXdh2p) in Escherichia coli and purified them as 6X-Histidine-tagged proteins. Biochemical characterization of the recombinant proteins reveals that
both PaXdh1p and PaXdh2p are thermotolerant enzymes. PaXdh2p contains a catalytic and a structural Zn atom. However, the structural
Zn atom is not present in PaXdh1p. Both enzymes also differ in their affinity for the substrate as well as in the catalytic
efficiency. Through mutagenesis and modeling approaches, we have also identified residues important for catalysis and substrate
binding. 相似文献
75.
76.
The apoplastic -amylase (EC 3.2.1.1
[EC]
) in pea (Pisum sativum L.cv. Laxton's Progress No. 9) seedlings was enhanced by a 4-to 6-fold with heat stress. Increased levels of the enzyme persistedfor 48 h at least after the stress and subsequent heat treatmentsenhanced the activity further. These results indicate that thefunction of apoplastic -amylase in vegetative tissues may berelated to plant stress. (Received October 14, 1996; Accepted February 20, 1997) 相似文献
77.
The effect of six naturally occurring prostaglandins on isolated umbilical arteries and veins has been studied. All six prostaglandins had a constricting effect on the umbilical vessels. On the umbilical artery preparations the potencies in decreasing order were A2>B2>F2α>B1>E2>A1. Prostaglandin B2 was more potent than PGA2 on the umbilical vein. Polyphloretin phosphate (PPP) antagonised the constricting effect of all six prostaglandins without altering responses to 5-hydroxytryptamine. 相似文献
78.
The cardiovascular, uterine stimulant and gastrointestinal effects of prostaglandins E2, F2α and 15 (S) 15 methyl PGE2 methyl ester in the East African Baboon (P. Anubis) have been studied. In these three parameters the baboon responds both qualitatively and quantitatively in a similar manner to man. The lethal doses of the prostaglandins given by bolus intravenous injelctions have been determined and the human lethal doses estimated. 相似文献
79.
S. M. M. Karim D. C. Carter D. Bhana P. Adaikan Ganesan 《BMJ (Clinical research ed.)》1973,1(5846):143-146
The effect of orally administered prostaglandin E2 and its synthetic 15-methyl analogues on gastric secretion in man was studied. The parent E2 compound did not inhibit basal secretion, whereas both the 15 (S) 15-methyl-E2 methyl ester and its isomer, 15 (R) 15-methyl-E2 methyl ester inhibited basal acid secretion. This action is likely to be a direct one on the parietal cell, and it could prove of value in the treatment of peptic ulcer. 相似文献
80.