Nutraceutical use of algae requires understanding of the diversity and significance of their active compositions for intended activities. Ishige okamurae (I. okamurae) extract is well-known to possess α-glucosidase inhibitory activity; however, studies are needed to investigate its active composition in order to standardize its α-glucosidase inhibitory activity. In this study, we observed the intensity of the dominant compounds of each I. okamurae extract harvested between 2016 and 2017, and the different potency of each I. okamurae extract against α-glucosidase. By comparing the anti-α-glucosidase ability of the dominant compounds, a novel Ishophloroglucin A with highest α-glucosidase inhibitory activity was identified and suggested for standardization of anti-α-glucosidase activity in I. okamurae extract. Additionally, a validated analytical method for measurement of Ishophloroglucin A for future standardization of I. okamurae extract was established in this study. We suggest using Ishophloroglucin A to standardize anti-α-glucosidase potency of I. okamurae and propose the significance of standardization based on their composition for effective use of algae as marine-derived nutraceuticals.

Introduction The inducible isoform of heme oxygenase (HO)-1 regulates the vascular smooth muscle tone and responds to hypoxia. Aim To investigate the role of HO-1 in a low-flow priapism. Materials and Methods Sixty male Sprague-Dawley rats were divided into five groups of six rats each. Each group of rats was sacrificed at 0 hour (group 1, control), 4 hours (group 2), 8 hours (group 3), 12 hours (group 4), and 24 hours (group 5) after inducing an artificial veno-occlusive priapism. The changes of the expression and activity of HO-1, and the expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS), and levels of cyclic guanosine monophosphate in the penis were examined in a low-flow priapism. In addition, the HO-1 expression level in the aortas from each group was simultaneously measured to determine whether the changes in HO-1 were systemic. Main Outcome Measures The expression and activity of HO-1 was examined in artificially induced veno-occlusive priapism in rat penile tissues. Results The expression of the HO-1 protein and the HO-1 enzyme activities in the penile tissues were gradually increased as time increased from 0 to 24 hours (P < 0.01). HO-1 immunoreactivities were localized in the endothelial layer of the cavernosal sinusoids. The expression of iNOS were also increased at 12 and 24 hours. The cyclic guanosine monophosphate level was also significantly increased at 24 hours (P < 0.05). However, the expression of the eNOS protein showed no statistically significant change with time, and the expression of the HO-1 protein in the aorta also showed no significant change with time. Conclusion A higher induction of HO-1 with time was observed in artificially induced veno-occlusive priapism, which might play a protective role against hypoxic injury. However, this may also play an important role in the vicious circle observed in a low-flow priapism.

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Among the many factors that encourage return patronage of incumbent technology, two that have received scholarly attention in other contexts are network externalities and switching costs. However, the roles of network externalities and switching costs in encouraging return patronage of technology have not yet been subjected to rigorous empirical testing. Furthermore, no examination has been conducted of the degree to which these factors play a role in the success or failure of corporate technology advancement strategies designed to encourage return patronage. In this context, we propose a systematic framework to explore the nature of the links between technology advancement strategies and consumer technology patronage via network externalities and switching costs. Based on consumer survey data from South Korea, we find empirical support for the link between technology advancement strategies and consumers' technology patronage. Specifically, both network externalities and switching costs are found to be positively associated with technology patronage. According to this study, consumers value compatibility because it gives them access to a larger network. Further, compatibility strategy is associated with the costs involved in switching away from incumbent technology because of an abundant or varied supply of complementary goods. The results also show that preannouncement is a key marketing strategy to achieve favorable expectations and to retain the patronage of current technology users. © 2002 Elsevier Science Inc. All rights reserved.

Purpose -To investigate shoppers' decision-making behaviour under conditions of expected and unexpected in-store price discounts, using mental accounting theory as the analytical framework. Design/methodology/approach -In an experiment manipulating expected and unexpected discounts on electronic organisers and portable audio players, data collected by questionnaire from 240 first-year business administration students at a Korean university were used to test two hypotheses predicting the ways in which the savings would be used. Findings -Recipients of unexpected discounts tend to spend the savings in store. If a choice of two products is available, the savings are more likely to be applied to the discounted one than the other. Shoppers commit more actively to planned purchases when price discounts are known in advance. The key factor in purchasing behaviour with respect to discounts is the existence or otherwise of predictions. Shoppers' decision-making in these conditions is, therefore, context and frame dependent.Research limitations/implications -The experimental subjects were not representative of the general shopping population, and Korea is a distinctive culture. The findings should be interpreted with caution, but are indicative within limits. Aspects of the topic not investigated by the experiment are identified, and future research directions suggested. Practical implications -Unadvertised discount available at the point of sale offer several potential benefits to retailers, including reduced costs and increased patronage. Pricing strategists need to understand the theoretical basis of customers' behaviour in response to discount offers, for effective planning. Originality/value -Adds to the body of knowledge relating to crucial aspect of pricing strategy, and has potential applicability beyond retailing.