Two new prenylated chalcones from the leaves of Artocarpus lowii King

Two minor prenylated chalcones were isolated for the first time from the leaves of Artocarpus lowii King. These prenylated chalcones were identified as 2- hydroxyparatocarpin C (1) and 2ʹ,3,4ʹ,4-tetrahydroxy-3ʹ-prenylchalcone (2). The structures of these prenylated chalcone were elucidated by utilizing the data values obtained from1H NMR,13C NMR, DEPT, COSY, IR, UV and MS, as well as by comparison with literature values

Cholinesterase inhibitors from heartwood of artocarpus fulvicortex F. M. Jarret (Moraceae)

Cholinesterase inhibition activities were screened on crude extracts and isolated compounds of the heartwood of Artocarpus fulvicortex. Phytochemical studies on the heartwood of A. fulvicortex have resulted in the isolation of one flavonoid, one stilbenoid and two triterpenes. Their structures were determined by spectroscopic analysis as catechin (1), oxyresveratrol (2), lupeol-3-acetate (3) and friedelin (4). All isolates were evaluated for the first time for anti-cholinesterase activity. Inhibition of acetylcholinesterase (AChE), tested by Ellman’s method and modified TLC bioautographic assay showed catechin (1) and oxyresvetratrol (2) were active agents with detection limit of 2 mM. The microplate assay was carried out using butyrylcholinesterase (BChe) to further confirmed that catechin (1) and oxyresvetratrol (2) displayed positive cholinesterase activity with IC50 values 50.0 mM and 6.25 mM respectively in dose dependent manner

Rancang Bangun Perangkat Lunak Sistem Auto Tracking Satellite Antenna Mobile Menggunakan Metode Azimut-elevasi Dan Koreksi Modem

Software Design of Mobile Antenna for Auto Satellite Tracking using Modem Correction and Elevation AzimuthMethod. Pointing accuracy is an important thing in satellite communication. Because the satellite’s distance to thesurface of the earth\u27s satellite is so huge, thus 1 degree of pointing error will make the antenna can not send data tosatellites. To overcome this, the auto-tracking satellite controller is made. This system uses a microcontroller as thecontroller, with the GPS as the indicator location of the antenna, digital compass as the beginning of antenna pointingdirection, rotary encoder as sensor azimuth and elevation, and modem to see Eb/No signal. The microcontroller useserial communication to read the input. Thus the programming should be focused on in the UART and serialcommunication software UART. This controller use 2 phase in the process of tracking satellites. Early stages is themethod Elevation-Azimuth, where at this stage with input from GPS, Digital Compass, and the position of satellites(both coordinates, and height) that are stored in microcontroller. Controller will calculate the elevation and azimuthangle, then move the antenna according to the antenna azimuth and elevation angle. Next stages is correction modem,where in this stage controller only use modem as the input, and antenna movement is set up to obtain the largest valueof Eb/No signal. From the results of the controller operation, there is a change in the value of the original input levelfrom -81.7 dB to -30.2 dB with end of Eb/No value, reaching 5.7 dB

Bioassay-guided isolation of antioxidants and ?-Glucosidase inhibitors from the root of cassia sieberiana D.C. (fabaceae)

Bioassay-guided isolation was used to investigate the antioxidants and α-glucosidase inhibitors from extract of root of Cassia sieberiana. The ethyl acetate fraction demonstrated strong free radical scavenging (DPPH and ABTS+) and potent α-glucosidase inhibition. The subsequent fractionation and purification of the ethyl acetate fraction using silica gel chromatography and Sephadex LH-20, yielded; islandicin (1), chrysophanol (2), physcion (3), emodin (4), quercetin (5), kaempferol (6), dihydrokaempferol (7), and piceatannol (8). Quercetin (5) showed the most active antioxidant activity with IC50 values of 1.58 mM and 1.30 mM against DPPH and ABTS+ radicals, followed by piceatannol (8) with IC50 values of 3.96 mM and 3.28 mM, which is better than the standard BHT (with IC50 value 8.93 mM) and trolox (with IC50 value 8.25 mM), for DPPH and ABTS+ radicals scavenging activities, respectively. For the α-glucosidase inhibitory assay, quercetin (5) and piceatannol (8) showed higher potency against α-glucosidase with IC50 values of 5.73 μM and 7.37 μM respectively, than standard quercetin with IC50 value of 9.20 μM and acarbose with IC50 value of 14.12 μM. This study presents the first report on the α-glucosidase inhibitors from root of C. sieberiana and all the compounds are isolated from this source for the first time

Synthesis of ferric-manganese doped tungstated zirconia nanoparticles as heterogeneous solid superacid catalyst for biodiesel production from waste cooking oil

The solid superacid catalyst ferric-manganese doped tungstated zirconia (FMWZ) nanoparticles was prepared by impregnation reaction followed by calcination at 600°C for 3 hr and had been characterized by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), temperature programmed desorption of NH3 (TPD-NH3), X-ray fluorescence (XRF), transmission electron microscopy (TEM), and Brunner-Emmett-Teller (BET) surface area measurement. The transesterification reaction was used to determine the optimum conditions of methanolysis of waste cooking oil with FMWZ nanoparticles as heterogeneous solid superacid catalyst. The reactions variables such as reaction temperatures, catalyst loading, molar ratio of methanol/oil and reusability were also assessed which effects the waste cooking oil methyl esters (WCOME’s) production yield. The catalyst was reused ten times without any loss in activity and maximum yield of 96% was achieved at the optimized conditions of reaction temperature of 200°C; stirring speed of 600 rpm, 1:25 molar ratio of oil to alcohol and 4% w/w catalyst loading. The fuel properties of the WCOME’s were discussed in light of ASTM D6751 biodiesel standard

Uncovering the Oppenheimer Siddur: using scientific analysis to reveal the production process of a medieval illuminated Hebrew manuscript

The aim of this research was to use non-invasive scientifc analysis to uncover evidence of the planning process and relationship between pigments used in text copying and artwork production in the Oppenheimer Siddur (Oxford Bodleian Library MS Opp. 776), an illuminated 15th-century Hebrew prayer book. In many medieval Hebrew illuminated manuscripts, the authorship of the artwork is unknown. This manuscript’s colophon states that it was copied by its scribe-owner for personal family use but does not confrm who was responsible for the artwork. Prior deductive analysis suggested that the scribe-owner may also have been the manuscript’s artist, based on common motifs and an apparent shared colour palette appearing in both texts and artwork. Visual examination using high resolution digital images also identifed points of contact between pigments used in the manuscript’s texts and artwork, raising questions about the pigment application sequence, and concurrent versus sequential text copying and artwork production. An in-house developed remote spectral imaging system (PRISMS) with 10 flters spanning the spectral range from 400 to 880 nm was modifed for close-range application to image two of the folios to examine the sequence of production, identify the pigments and compare the materials used for the illumination and the text. Optical microscopy and Fourier Transform Infrared spectroscopy in the attenuated total refection mode (FTIR-ATR) were used directly on the folios to complement the spectral imaging data in binding media and pigment identifcation. The results revealed close matches in refectance spectra for the colorants and inks used in both text copying and illuminations, suggesting that the same mixture of colorants and inks have been used. The spectral imaging in the near infrared bands revealed a hidden underdrawing, indicating a design change during production of the manuscript, and the outlining of letters prior to coloured pigment being applied. The pigment use, the variation in the binder for diferent pigments and some elements of its production were found to be consistent with those described in historical sources. The evidence from this study supports the hypothesis that the scribe applied pigments for the manuscript’s artwork at the same time he did some of the scribal work which has implications for understandings of Jewish medieval visual cultures

A new stilbene from the root of cassia sieberiana D.C. (Fabaceae)

A new stilbene (1) was isolated from the root of Cassia sieberiana D. C. together with thirteen known compounds, one stilbene (2), three flavonoids (3-5), six anthraquinones (6-11), two triterpenes (12-13), and phytosterol (14). Their structures were identified using spectroscopic techniques and by comparison of the spectral data with those previously reported in the literature. Compounds 10-13 were isolated from C. sieberiana for the first time. Compounds 1, 2 and 3 exhibited significant inhibitory activity on 15-lipoxygenase with IC50 values of 2.62, 1.27 and 0.98 ìM, respectively. Compounds 2 and 3 showed acetylcholinesterase inhibitory activity with IC50 values of 10.57 and 2.89 ìM, respectively

Data integrity for dynamic big data in cloud storage: A comprehensive review and critical issues

Cloud storage services provide vast storage space to solve the bottleneck of the data generated by different big data applications. However, the nature of big data in terms of its massive volume and rapid velocity, needs to be considered when designing data integrity schemes to provide security assurance for data stored in the cloud. The state of the art of data integrity in the cloud includes two primary schemes: (i) Proof of Retrievability (POR) and (ii) Provable Data Possession. Both techniques are designed to achieve the same goal in ensuring data integrity of outsourced data in cloud storage, However, PoR varies from PDP by error-correcting feature to retrieve the damaged outsourced data. This paper focuses on the proof of data retrievability technique (POR) for dynamic data. Dynamic data is defined as data under different update operations. The paper surveys the state of the art data integrity techniques for cloud storage (CS) and previous work on basic requirements for an effective data integrity technique for big data applications. Methods used to provide dynamic PoR are discussed before summarizing the classification of the POR state-of-the-art. The recently proposed techniques and their limitations are also discussed with issues to consider for future POR scheme design