Vida Šimat

Bio: Vida Šimat is an academic researcher from University of Split. The author has contributed to research in topics: Lipid oxidation & Anisakis. The author has an hindex of 17, co-authored 48 publications receiving 783 citations. Previous affiliations of Vida Šimat include University of Zagreb.

Phenolic Content of Brown Algae (Pheophyceae) Species: Extraction, Identification, and Quantification

Abstract: Over the last few decades, isolations and chemical characterizations of secondary metabolites with proved biological activities have been of interest for numerous research groups across the world. Phenolics, as one of the largest and most widely distributed group of phytochemicals, have gained special attention due to their pharmacological activity and array of health-promoting benefits. Reports on phenolic potentials of marine algae, especially brown algae (Pheophyceae) that are characterized by the presence of phlorotannins, are still scarce. The aim of this review paper is to provide an overview of current knowledge about phenolic potential of different brown algae species (74 species from 7 different orders). Studies on brown algae phenolics usually involve few species, thus the focus of this review is to provide information about the phenolic potential of reported algae species and to get an insight into some issues related to the applied extraction procedures and determination/quantification methods to facilitate the comparison of results from different studies. The information provided through this review should be useful for the design and interpretation of studies investigating the brown algae as a source of valuable phytochemicals.

Seasonal Variations of Phenolic Compounds and Biological Properties in Sage (Salvia officinalis L.)

Abstract: The aim was to investigate the phenolic content, antioxidant capacity, and antibacterial activity of Dalmatian sage (Salvia officinalis L.) leaves collected during different vegetation periods. Separation and quantification of the individual phenols were performed by reversed-phase (RP)-HPLC coupled with a PDA (photodiode array) detector and using an internal standard, while the contents of total phenols, flavonoids, flavones, and flavonols were determined spectrophotometrically. The antioxidant properties of the sage leaf extracts were evaluated using five different antioxidant assays (FRAP, DPPH, ABTS, Briggs-Rauscher reaction, and β-carotene bleaching). The antimicrobial activity of the extracts was tested against two Gram-positive (Bacillus cereus and Staphylococcus aureus) and two Gram-negative (Salmonella Infantis and Escherichia coli) bacterial reference strains. All extracts were extremely rich in phenolic compounds, and provided good antioxidant and antibacterial properties, but the phenophase in which the leaves were collected affected the phenolic composition of the sage extracts and consequently their biological activity. The May Extract, the richest in total flavonoids, showed the best antioxidant properties and the highest antimicrobial activity. Thus, collection of the plants during May seems the best choice for further use of them in the pharmaceutical and food industry.

Natural Products for Drug Discovery in the 21st Century: Innovations for Novel Drug Discovery.

Abstract: The therapeutic properties of plants have been recognised since time immemorial. Many pathological conditions have been treated using plant-derived medicines. These medicines are used as concoctions or concentrated plant extracts without isolation of active compounds. Modern medicine however, requires the isolation and purification of one or two active compounds. There are however a lot of global health challenges with diseases such as cancer, degenerative diseases, HIV/AIDS and diabetes, of which modern medicine is struggling to provide cures. Many times the isolation of “active compound” has made the compound ineffective. Drug discovery is a multidimensional problem requiring several parameters of both natural and synthetic compounds such as safety, pharmacokinetics and efficacy to be evaluated during drug candidate selection. The advent of latest technologies that enhance drug design hypotheses such as Artificial Intelligence, the use of ‘organ-on chip’ and microfluidics technologies, means that automation has become part of drug discovery. This has resulted in increased speed in drug discovery and evaluation of the safety, pharmacokinetics and efficacy of candidate compounds whilst allowing novel ways of drug design and synthesis based on natural compounds. Recent advances in analytical and computational techniques have opened new avenues to process complex natural products and to use their structures to derive new and innovative drugs. Indeed, we are in the era of computational molecular design, as applied to natural products. Predictive computational softwares have contributed to the discovery of molecular targets of natural products and their derivatives. In future the use of quantum computing, computational softwares and databases in modelling molecular interactions and predicting features and parameters needed for drug development, such as pharmacokinetic and pharmacodynamics, will result in few false positive leads in drug development. This review discusses plant-based natural product drug discovery and how innovative technologies play a role in next-generation drug discovery.

17세기 네덜란드 미술에 나타난 빵의 사회사

Abstract: 본 연구는 현존하는 여덟 개의 〈뿔피리를 부는 제빵사〉 작품이 산발적으로 우연히 등장한 것이 아닌 서로 유기적인 영향관계를 주고 받으며 생산된 하나의 도상으로 살펴보았다. “뿔피리를 부는 제빵사” 그림에 대한 현재까지의 연구는 대부분 그림에 나타나 있는 다양한 빵들을 성만찬을 의미하는 종교적 상징으로 해석하고 있다. 이에 반해 본 연구는 “뿔피리를 부는 제빵사” 도상이 유독 17세기 중후반 네덜란드에서 생산된 사실에 주목하고, 그 이유를 동시대 네덜란드인들의 일상에 직접적인 영향을 주었던 빵의 생산 및 공급 그리고 유통과정에서 찾고자 한다. 여기에는 빵이 당대 네덜란드인들의 식생활 뿐 아니라 그들의 경제생활 더나아가 국가경제 전체에 어떤 중요한 역할을 했는지에 대한 연구가 선행되어야 한다. 주로 풍속화의 전통으로 해석되었던 “뿔피리를 부는 제빵사” 그림은 본 연구에서 풍속화와 초상화 두 장르가 혼합한 도상으로 다루어졌으며, 이제까지의 연구에서 미흡했던 초상화로서의 가능성이 적극적으로 제기되었다. 제빵사의 초상화 또는 화가의 자화상으로 생산된 〈뿔피리를 부는 제빵사〉의 시대적 배경에는 제빵사의 경제적 여유와 사회적 지위상승 그리고 제빵사를 영혼의 양식을 공급하는 고귀한 직업으로 승화시킨 칼비니즘의 영향이 있다. 제빵사들이 부를 축적할 수 있었던 배경에는 국가가 나서서 빵의 생산과 공급을 철저하게 관리해준 덕분이었다. 17세기 네덜란드의 제빵사들은 길드에 속해야만 빵을 팔 수 있었고 각 제빵사들의 빵 만드는 법은 외부인들에게 절대로 공개되지 않았다. 동시에 당시 네덜란드인들은 세금을 내지 않고는 빵을 먹기가 힘들었다. 이런 이유로 개인의 집에 오븐을 설치하는 것은 금지되었고, 빵은 꼭 관헌들에게 세금을 내는 합법적인 제빵사에게서만 살 수 있었다. 이렇게 17세기 네덜란드는 직업으로서 빵 굽는 사람을 보호하는 동시에 단속하기 위해 매우 엄격한 규정을 제정하였다. 17세기 네덜란드인들에게 빵은 그들의 식생활 뿐 아니라 그들의 다양한 직업과도 관련이 있었으며 빵의 생산과 유통과정에 개입한 국가의 권위와 통제를 상징하기도 한다. 빵의 생산과 유통에 붙는 세금은 국가의 경제를 지탱하고 발전시키는데 중요한 재원이었으며, 동시에 국민들을 엄격하게 관리함으로써 국가의 질서를 세우기 위한 효과적인 방편이었다. 빵가격은 변동이 심한 곡물가격과 빵의 크기에 따라서 엄격하게 결정되었다. 네덜란드정부는 평상시에 빵의 공식적인 무게와 가격을 고정시켰는데, 이는 다른 음식에서는 찾아볼 수 없는 유일한 관리방식이었다. 따라서 동시대 네덜란드인들에게 빵은 국가의 적극적인 개입과 관리체계를 통해서만 그들의 입에 넣을 수 있는 음식이었다. 이러한 맥락에서 볼 때, 본 연구에서 다룬 〈뿔피리를 부는 제빵사〉 그림에서 풍성하게 차려진 다양한 빵은 경제적인 풍요와 정치적인 안정을 의미한다. 여러 가지 다양한 음식 중에서도 빵이 이러한 의미를 가장 효과적으로 전달한다는 점에서 〈뿔피리를 부는 제빵사〉 그림에서 빵은 당시 네덜란드의 물질적 풍요뿐만 아니라 국가의 번영과 안녕을 의미한다고 볼 수 있다.

Antioxidant Activity/Capacity Measurement. 1. Classification, Physicochemical Principles, Mechanisms, and Electron Transfer (ET)-Based Assays.

Abstract: Because there is no widely adopted “total antioxidant parameter” as a nutritional index for labeling food and biological fluids, it is desirable to establish and standardize methods that can measure the total antioxidant capacity (TAC) level directly from plant-based food extracts and biological fluids. In this review, we (i) present and classify the widely used analytical approaches (e.g., in vitro and in vivo, enzymatic and nonenzymatic, electron transfer (ET)- and hydrogen atom transfer (HAT)-based, direct and indirect assays) for evaluating antioxidant capacity/activity; (ii) discuss total antioxidant capacity/activity assays in terms of chemical kinetics and thermodynamics, reaction mechanisms, and analytical performance characteristics, together with advantages and drawbacks; and (iii) critically evaluate ET-based methods for analytical, food chemical, biomedical/clinical, and environmental scientific communities so that they can effectively use these assays in the correct places to meet their needs.

Trophic transfer, bioaccumulation, and biomagnification of non-essential hazardous heavy metals and metalloids in food chains/webs—Concepts and implications for wildlife and human health

Abstract: Heavy metals are transferred from the abiotic environment to living organisms, accumulated in biota at different trophic levels, and thus contaminate the food chains/webs. Trophic transfer, bioaccu...

Antibacterial and Antifungal Activities of Spices

Abstract: Infectious diseases caused by pathogens and food poisoning caused by spoilage microorganisms are threatening human health all over the world. The efficacies of some antimicrobial agents, which are currently used to extend shelf-life and increase the safety of food products in food industry and to inhibit disease-causing microorganisms in medicine, have been weakened by microbial resistance. Therefore, new antimicrobial agents that could overcome this resistance need to be discovered. Many spices—such as clove, oregano, thyme, cinnamon, and cumin—possessed significant antibacterial and antifungal activities against food spoilage bacteria like Bacillus subtilis and Pseudomonas fluorescens, pathogens like Staphylococcus aureus and Vibrio parahaemolyticus, harmful fungi like Aspergillus flavus, even antibiotic resistant microorganisms such as methicillin resistant Staphylococcus aureus. Therefore, spices have a great potential to be developed as new and safe antimicrobial agents. This review summarizes scientific studies on the antibacterial and antifungal activities of several spices and their derivatives.