Alkaloids are a diverse group of natural phytochemicals.These phytochemicals in plants provide them protection against pests,and herbivorous organisms and also control their development.Numerous of these alkaloids hav...Alkaloids are a diverse group of natural phytochemicals.These phytochemicals in plants provide them protection against pests,and herbivorous organisms and also control their development.Numerous of these alkaloids have a variety of biological effects,and some have even been developed into medications with different medicinal properties.This review aims to provide a broad overview of the numerous naturally occurring alkaloids(isolated from both terrestrial and aquatic species)along with synthetically produced alkaloid compounds having prominent antiviral properties.Previous reviews on this subject have focused on the biological actions of both natural and synthetic alkaloids,but they have not gone into comprehensive detail about their antiviral properties.We reviewed here several antiviral alkaloids that have been described in the literature in different investigational environments i.e.(in-vivo,in-ovo,in-vitro,and in-silico),and found that these alkaloid compounds have significant antiviral properties against several infectious viruses.These alkaloids repressed and targeted various important stages of viral infection at non-toxic doses while some of the alkaloids reported here also exhibited comparable inhibitory activities to commercially used drugs.Overall,these anti-viral effects of alkaloids point to a high degree of specificity,implying that they could serve as effective and safe antiviral medicines if further pursued in medicinal and pharmacological investigations.展开更多
The deep-sea brines of the Red Sea include some of the most extreme and unique envi- ronments on Earth. They combine high salinities with increases in temperature, heavy metals, hydrostatic pressure, and anoxic condit...The deep-sea brines of the Red Sea include some of the most extreme and unique envi- ronments on Earth. They combine high salinities with increases in temperature, heavy metals, hydrostatic pressure, and anoxic conditions, creating unique settings for thriving populations of novel extremophiles. Despite a recent increase of studies focusing on these unusual biotopes, their viral communities remain unexplored. The current survey explores four metagenomic datasets obtained from different brine-seawater interface samples, focusing specifically on the diversity of their viral communities. Data analysis confirmed that the particle-attached viral communities present in the brine-seawater interfaces were diverse and generally dominated by Candovirales, yet appearing distinct from sample to sample. With a level of caution, we report the unexpected finding of Phycodnaviridae, which infects algae and plants, and trace amounts of insect-infecting Iridoviridae. Results from Kebrit Deep revealed stratification in the viral communities present in the interface： the upper-interface was enriched with viruses associated with typical marine bacteria, while the lower-interface was enriched with haloviruses and halophages. These results provide first insights into the unexplored viral communities present in deep-sea brines of the Red Sea, represent- ing one of the first steps for ongoing and future sampling efforts and studies.展开更多
Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with convention...Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with conventional synthetic antibiotics.Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen.In this study,we have investigated the antimicrobial activity of a purple violet pigment(PVP)from an Antarctic bacterium,Janthinobacterium sp.Ant5-2 on 15 clinical MDR and MRSA strains.The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration(MIC90)of PVP against MDR and MRSA.The MIC90 ranged between 1.57μg/mL and 3.13μg/mL,which are significantly lower than many antimicrobials tested from natural sources against this pathogen.The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead®BacLight™fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels.In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound.The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.展开更多
Since ancient times,the inhabitants of dry areas have depended on the date palm(Phoenix dactylifera L.)as a staple food and means of economic security.For example,dates have been a staple diet for the inhabitants of t...Since ancient times,the inhabitants of dry areas have depended on the date palm(Phoenix dactylifera L.)as a staple food and means of economic security.For example,dates have been a staple diet for the inhabitants of the Arabian Peninsula and Sahara Desert in North Africa for millennia and the local culture is rich in knowledge and experience with the benefits of dates,suggesting that dates contain many substances essential for the human body.Madinah dates are considered one of the most important types of dates in the Arabian Peninsula,with Ajwa being one of the most famous types and grown only in Madinah,Saudi Arabia.Date seeds are traditionally used for animal feed,seed oil production,cosmetics,and as a coffee substitute.Phytochemical compounds that have been detected in date fruits and date seeds include phenolic acids,carotenoids,and flavonoids.Phenolic acids are the most prevalent bioactive constituents that contribute to the antioxidant activity of date fruits.The bioactive properties of these phytochemicals are believed to promote human health by reducing the risk of diseases such as chronic inflammation.Ajwa dates especially are thought to have superior bioactivity properties.To investigate these claims,in this study,we compare the metabolic profiles of Ajwa with different types of dates collected from Saudi Arabia and Tunisia.We show by UHPLC-MS that date seeds contain several classes of flavonoids,phenolic acids,and amino acid derivatives,including citric acid,malic acid,lactic acid,and hydroxyadipic acid.Additionally,GC-MS profiling showed that date seeds are richer in metabolite classes,such as hydrocinnamic acids(caffeic,ferulic and sinapic acids),than flesh samples.Deglet N fruit extract(minimum inhibitory concentration:27 MIC/μM)and Sukkari fruit extract(IC_(50):479±0.58μg/mL)have higher levels of antibacterial and antioxidative activity than Ajwa fruits.However,the seed analysis showed that seed extracts have better bioactivity effects than fruit extracts.Specifically,Ajwa extract showed the best MIC and strongest ABTS radical-scavenging activity among examined seed extracts(minimum inhibitory concentration:20μM;IC_(50):54±3.61μg/mL).Our assays are a starting point for more advanced in vitro antibacterial models and investigation into the specific molecules that are responsible for the antioxidative and anti-bacterial activities of dates.展开更多
Current marine research primarily depends on weighty and invasive sensory equipment and telemetric network to understand the marine environment,including the diverse fauna it contains,as a function of animal behavior ...Current marine research primarily depends on weighty and invasive sensory equipment and telemetric network to understand the marine environment,including the diverse fauna it contains,as a function of animal behavior and size,as well as equipment longevity.To match animal morphology and activity within the surrounding marine environment,here we show a physically flexible and stretchable skin-like and waterproof autonomous multifunctional system,integrating Bluetooth,memory chip,and high performance physical sensors.The sensory tag is mounted on a swimming crab(Portunus pelagicus)and is capable of continuous logging of depth,temperature,and salinity within the harsh ocean environment.The fully packaged,ultra-lightweight(<2.4 g in water),and compliant“Marine Skin”system does not have any wired connection enabling safe and weightless cuttingedge approach to monitor and assess marine life and the ecosystem’s health to support conservation and management of marine ecosystems.展开更多
The outstanding properties of graphene have initiated myriads of research and development;yet, its economic impact is hamperedby the difficulties encountered in production and practical application. Recently discovere...The outstanding properties of graphene have initiated myriads of research and development;yet, its economic impact is hamperedby the difficulties encountered in production and practical application. Recently discovered laser-induced graphene is generated bya simple printing process on flexible and lightweight polyimide films. Exploiting the electrical features and mechanical pliability ofLIG on polyimide, we developed wearable resistive bending sensors that pave the way for many cost-effective measurementsystems. The versatile sensors we describe can be utilized in a wide range of configurations, including measurement of force,deflection, and curvature. The deflection induced by different forces and speeds is effectively sensed through a resistancemeasurement, exploiting the piezoresistance of the printed graphene electrodes. The LIG sensors possess an outstanding range forstrain measurements reaching >10% A double-sided electrode concept was developed by printing the same electrodes on bothsides of the film and employing difference measurements. This provided a large bidirectional bending response combined withtemperature compensation. Versatility in geometry and a simple fabrication process enable the detection of a wide range of flowspeeds, forces, and deflections. The sensor response can be easily tuned by geometrical parameters of the bending sensors and theLIG electrodes. As a wearable device, LIG bending sensors were used for tracking body movements. For underwater operation,PDMS-coated LIG bending sensors were integrated with ultra-low power aquatic tags and utilized in underwater animal speedmonitoring applications, and a recording of the surface current velocity on a coral reef in the Red Sea.展开更多
Graphene has shown considerable potential for sensing magnetic fields based on the Hall Effect,due to its high carrier mobility,low sheet carrier density,and low-temperature dependence.However,the cost of graphene in ...Graphene has shown considerable potential for sensing magnetic fields based on the Hall Effect,due to its high carrier mobility,low sheet carrier density,and low-temperature dependence.However,the cost of graphene in comparison to conventional materials has meant that its uptake in electronic manufacturing has been slow.To lower technological barriers and bring more widespread adoption of graphene Hall sensors,we are using a one-step laser scribing process that does not rely on multiple steps,toxic chemicals,and subsequent treatments.Laser-scribed graphene Hall sensors offer a linear response to magnetic fields with a normalized sensitivity of~1.12 V/AT.They also exhibit a low constant noise voltage floor of~50 nV√Hz p for a bias current of 100μA at room temperature,which is comparable with state-of-the-art low-noise Hall sensors.The sensors combine a high bendability,come with high robustness and operating temperatures up to 400°C.They enable device ideas in various areas,for instance,soft robotics.As an example,we combined a laser-scribed graphene sensor with a deformable elastomer and flexible magnet to realize low-cost,compliant,and customizable tactile sensors.展开更多
文摘Alkaloids are a diverse group of natural phytochemicals.These phytochemicals in plants provide them protection against pests,and herbivorous organisms and also control their development.Numerous of these alkaloids have a variety of biological effects,and some have even been developed into medications with different medicinal properties.This review aims to provide a broad overview of the numerous naturally occurring alkaloids(isolated from both terrestrial and aquatic species)along with synthetically produced alkaloid compounds having prominent antiviral properties.Previous reviews on this subject have focused on the biological actions of both natural and synthetic alkaloids,but they have not gone into comprehensive detail about their antiviral properties.We reviewed here several antiviral alkaloids that have been described in the literature in different investigational environments i.e.(in-vivo,in-ovo,in-vitro,and in-silico),and found that these alkaloid compounds have significant antiviral properties against several infectious viruses.These alkaloids repressed and targeted various important stages of viral infection at non-toxic doses while some of the alkaloids reported here also exhibited comparable inhibitory activities to commercially used drugs.Overall,these anti-viral effects of alkaloids point to a high degree of specificity,implying that they could serve as effective and safe antiviral medicines if further pursued in medicinal and pharmacological investigations.
基金the support through the KAUST baseline research funds to VBBpartially supported by the KAUST-AUC Global Collaborative Research Program
文摘The deep-sea brines of the Red Sea include some of the most extreme and unique envi- ronments on Earth. They combine high salinities with increases in temperature, heavy metals, hydrostatic pressure, and anoxic conditions, creating unique settings for thriving populations of novel extremophiles. Despite a recent increase of studies focusing on these unusual biotopes, their viral communities remain unexplored. The current survey explores four metagenomic datasets obtained from different brine-seawater interface samples, focusing specifically on the diversity of their viral communities. Data analysis confirmed that the particle-attached viral communities present in the brine-seawater interfaces were diverse and generally dominated by Candovirales, yet appearing distinct from sample to sample. With a level of caution, we report the unexpected finding of Phycodnaviridae, which infects algae and plants, and trace amounts of insect-infecting Iridoviridae. Results from Kebrit Deep revealed stratification in the viral communities present in the interface： the upper-interface was enriched with viruses associated with typical marine bacteria, while the lower-interface was enriched with haloviruses and halophages. These results provide first insights into the unexplored viral communities present in deep-sea brines of the Red Sea, represent- ing one of the first steps for ongoing and future sampling efforts and studies.
文摘Multiple drug resistant(MDR)and methicillin-resistant Staphylococcus aureus(MRSA)have become increasingly prevalent as a community acquired infection.As a result limited treatment options are available with conventional synthetic antibiotics.Bioprospecting natural products with potent antimicrobial activity show promise for developing new drugs against this pathogen.In this study,we have investigated the antimicrobial activity of a purple violet pigment(PVP)from an Antarctic bacterium,Janthinobacterium sp.Ant5-2 on 15 clinical MDR and MRSA strains.The colorimetric resazurin assay was employed to determine the minimum inhibitory concentration(MIC90)of PVP against MDR and MRSA.The MIC90 ranged between 1.57μg/mL and 3.13μg/mL,which are significantly lower than many antimicrobials tested from natural sources against this pathogen.The spectrophotometrically determined growth analysis and total microscopic counts using Live/dead®BacLight™fluorescent stain exhibited a steady decrease in viability of both MDR and MRSA cultures following treatment with PVP at the MIC levels.In silico predictive molecular docking study revealed that PVP could be a DNA-targeting minor groove binding antimicrobial compound.The continued development of novel antimicrobials derived from natural sources with the combination of a suite of conventional antibiotics could stem the rising pandemic of MDR and MRSA along with other deadly microbial pathogens.
基金KAUST Smart Health Initiative grants(SHI REI 4447)(MJ)and through baseline-funds(MJ).
文摘Since ancient times,the inhabitants of dry areas have depended on the date palm(Phoenix dactylifera L.)as a staple food and means of economic security.For example,dates have been a staple diet for the inhabitants of the Arabian Peninsula and Sahara Desert in North Africa for millennia and the local culture is rich in knowledge and experience with the benefits of dates,suggesting that dates contain many substances essential for the human body.Madinah dates are considered one of the most important types of dates in the Arabian Peninsula,with Ajwa being one of the most famous types and grown only in Madinah,Saudi Arabia.Date seeds are traditionally used for animal feed,seed oil production,cosmetics,and as a coffee substitute.Phytochemical compounds that have been detected in date fruits and date seeds include phenolic acids,carotenoids,and flavonoids.Phenolic acids are the most prevalent bioactive constituents that contribute to the antioxidant activity of date fruits.The bioactive properties of these phytochemicals are believed to promote human health by reducing the risk of diseases such as chronic inflammation.Ajwa dates especially are thought to have superior bioactivity properties.To investigate these claims,in this study,we compare the metabolic profiles of Ajwa with different types of dates collected from Saudi Arabia and Tunisia.We show by UHPLC-MS that date seeds contain several classes of flavonoids,phenolic acids,and amino acid derivatives,including citric acid,malic acid,lactic acid,and hydroxyadipic acid.Additionally,GC-MS profiling showed that date seeds are richer in metabolite classes,such as hydrocinnamic acids(caffeic,ferulic and sinapic acids),than flesh samples.Deglet N fruit extract(minimum inhibitory concentration:27 MIC/μM)and Sukkari fruit extract(IC_(50):479±0.58μg/mL)have higher levels of antibacterial and antioxidative activity than Ajwa fruits.However,the seed analysis showed that seed extracts have better bioactivity effects than fruit extracts.Specifically,Ajwa extract showed the best MIC and strongest ABTS radical-scavenging activity among examined seed extracts(minimum inhibitory concentration:20μM;IC_(50):54±3.61μg/mL).Our assays are a starting point for more advanced in vitro antibacterial models and investigation into the specific molecules that are responsible for the antioxidative and anti-bacterial activities of dates.
基金This publication is based upon work supported by the King Abdullah University of Science and Technology(KAUST)Office of Sponsored Research(OSR)under Award No.Sensor Innovation Initiative OSR-2015-Sensors-2707.
文摘Current marine research primarily depends on weighty and invasive sensory equipment and telemetric network to understand the marine environment,including the diverse fauna it contains,as a function of animal behavior and size,as well as equipment longevity.To match animal morphology and activity within the surrounding marine environment,here we show a physically flexible and stretchable skin-like and waterproof autonomous multifunctional system,integrating Bluetooth,memory chip,and high performance physical sensors.The sensory tag is mounted on a swimming crab(Portunus pelagicus)and is capable of continuous logging of depth,temperature,and salinity within the harsh ocean environment.The fully packaged,ultra-lightweight(<2.4 g in water),and compliant“Marine Skin”system does not have any wired connection enabling safe and weightless cuttingedge approach to monitor and assess marine life and the ecosystem’s health to support conservation and management of marine ecosystems.
基金This research is a contribution to the CAASE project funded by King Abdullah University of Science and Technology(KAUST)under the KAUST Sensor Initiative.
文摘The outstanding properties of graphene have initiated myriads of research and development;yet, its economic impact is hamperedby the difficulties encountered in production and practical application. Recently discovered laser-induced graphene is generated bya simple printing process on flexible and lightweight polyimide films. Exploiting the electrical features and mechanical pliability ofLIG on polyimide, we developed wearable resistive bending sensors that pave the way for many cost-effective measurementsystems. The versatile sensors we describe can be utilized in a wide range of configurations, including measurement of force,deflection, and curvature. The deflection induced by different forces and speeds is effectively sensed through a resistancemeasurement, exploiting the piezoresistance of the printed graphene electrodes. The LIG sensors possess an outstanding range forstrain measurements reaching >10% A double-sided electrode concept was developed by printing the same electrodes on bothsides of the film and employing difference measurements. This provided a large bidirectional bending response combined withtemperature compensation. Versatility in geometry and a simple fabrication process enable the detection of a wide range of flowspeeds, forces, and deflections. The sensor response can be easily tuned by geometrical parameters of the bending sensors and theLIG electrodes. As a wearable device, LIG bending sensors were used for tracking body movements. For underwater operation,PDMS-coated LIG bending sensors were integrated with ultra-low power aquatic tags and utilized in underwater animal speedmonitoring applications, and a recording of the surface current velocity on a coral reef in the Red Sea.
基金funded by King Abdullah University of Science and Technology(KAUST)under the KAUST Sensor Initiative.B.A.Kaidarova et al.6 npj Flexible。
文摘Graphene has shown considerable potential for sensing magnetic fields based on the Hall Effect,due to its high carrier mobility,low sheet carrier density,and low-temperature dependence.However,the cost of graphene in comparison to conventional materials has meant that its uptake in electronic manufacturing has been slow.To lower technological barriers and bring more widespread adoption of graphene Hall sensors,we are using a one-step laser scribing process that does not rely on multiple steps,toxic chemicals,and subsequent treatments.Laser-scribed graphene Hall sensors offer a linear response to magnetic fields with a normalized sensitivity of~1.12 V/AT.They also exhibit a low constant noise voltage floor of~50 nV√Hz p for a bias current of 100μA at room temperature,which is comparable with state-of-the-art low-noise Hall sensors.The sensors combine a high bendability,come with high robustness and operating temperatures up to 400°C.They enable device ideas in various areas,for instance,soft robotics.As an example,we combined a laser-scribed graphene sensor with a deformable elastomer and flexible magnet to realize low-cost,compliant,and customizable tactile sensors.
