46 research outputs found
Synthesis of New Star-Shaped Liquid Crystalline Cyclotriphosphazene Derivatives with Fire Retardancy Bearing Amide-Azo and Azo-Azo Linking Units
Two series of new hexasubstituted cyclotriphosphazene derivatives were successfully synthesized and characterized. These derivatives are differentiated by two types of linking units in the molecules such as amide-azo (6a–j) and azo-azo (8a–j). The homologues of the same series contain different terminal substituents such as heptyl, nonyl, decyl, dodecyl, tetradecyl, hydroxyl, carboxyl, chloro, nitro, and amino groups. All the intermediates and final compounds were characterized using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), and Carbon, Hydrogen, and Nitrogen (CHN) elemental analysis. Liquid crystal properties for all compounds were determined using polarized optical microscope (POM). It was found that only intermediates 2a–e with nitro and alkoxyl terminal chains showed a smectic A phase. All the final compounds with alkoxyl substituents are mesogenic with either smectic A or C phases. However, other intermediates and compounds were found to be non-mesogenic. The study on the fire retardancy of final compounds was determined using limiting oxygen index (LOI) method. The LOI value of pure polyester resin (22.53%) was increased up to 24.71% after treating with 1 wt% of hexachlorocyclotriphosphazene (HCCP). Moreover, all the compounds gave positive results on the LOI values and compound 6i with the nitro terminal substituent showed the highest LOI value of 27.54%
Chemical Constituents and Antioxidant Activity of Teucrium barbeyanum Aschers
The different extracts of the aerial parts of Teucrium barbeyanum Aschers. were investigated for the
chemical constituents and antioxidant activities. The chemical investigation of the plant led to the isolation of
eleven known compounds through column chromatography in which nine were flavonoids and the other two
were simple phenolic compounds. The compounds were characterized using NMR techniques (1H, 13C, DEPT-
135 and 90, COSY, HMQC, HMBC and NOESY), UV spectroscopy and EI/ESI spectrometry. The isolated
compounds were identified as 5-hydroxy-3,6,7,4�-tetramethoxyflavone (1), salvigenin (2), 5-hydroxy-6,7,3�,4�-
tetramethoxyflavone (3), chrysosplenetin (4), cirsilineol (5), cirsimaritin (6), cirsiliol (7), apigenin (8) and
luteolin (9), in addition to methyl caffeate (10) and 4-hydroxybenzoic acid (11). The antioxidant activity of the
extracts was evaluated using 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2�-Azino-bis(3-ethylbenzothiazoline-6-
sulfonic acid) diammonium salt (ABTS) and ferric reducing antioxidant power (FRAP) methods. Ethyl acetate
and butanol extracts showed comparable antioxidant activity to known antioxidants; trolox and ascorbic acid and
the highest total phenolic and flavonoid contents. The active components were extracted efficiently in 70%
aqueous methanol after defatting procedure. This is the first time the aforementioned compounds are isolated
from this plant, and there has been no previous report on the biological studies on this species
Ethyl 4-(1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-2-yl)benzoate
The title compound, C21H15NO4, was synthesized by reducing the Schiff base obtained from acenaphthenequinone and ethyl-4-aminobenzoate. The dihedral angle between the essentially planar 1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinoline ring system [maximum deviation = 0.061 (2) Å] and the benzene ring is 75.08 (10)°. In the crystal, molecules are connected via weak intermolecular C—H⋯O hydrogen bonds, forming a two-dimensional network. The ethyl group is disordered over two sets of sites with a refined occupancy ratio of 0.502 (12):0.498 (12)
A Marine Actinomycete Rescues Caenorhabditis elegans from Pseudomonas aeruginosa Infection through Restitution of Lysozyme 7
The resistance of Pseudomonas aeruginosa to conventional antimicrobial treatment is a
major scourge in healthcare. Therefore, it is crucial that novel potent anti-infectives are
discovered. The aim of the present study is to screen marine actinomycetes for chemical
entities capable of overcoming P. aeruginosa infection through mechanisms involving
anti-virulence or host immunity activities. A total of 18 actinomycetes isolates were
sampled from marine sediment of Songsong Island, Kedah, Malaysia. Upon confirming
that the methanolic crude extract of these isolates do not display direct bactericidal
activities, they were tested for capacity to rescue Caenorhabditis elegans infected
with P. aeruginosa strain PA14. A hexane partition of the extract from one isolate,
designated as Streptomyces sp. CCB-PSK207, could promote the survival of PA14
infected worms by more than 60%. Partial 16S sequence analysis on this isolate showed
identity of 99.79% with Streptomyces sundarbansensis. This partition did not impair
feeding behavior of C. elegans worms. Tested on PA14, the partition also did not affect
bacterial growth or its ability to colonize host gut. The production of biofilm, protease,
and pyocyanin in PA14 were uninterrupted, although there was an increase in elastase
production. In lys-7::GFP worms, this partition was shown to induce the expression
of lysozyme 7, an important innate immunity defense molecule that was repressed
during PA14 infection. GC-MS analysis of the bioactive fraction of Streptomyces sp.
CCB-PSK207 revealed the presence of methyl esters of branched saturated fatty acids.
In conclusion, this is the first report of a marine actinomycete producing metabolites
capable of rescuing C. elegans from PA14 through a lys-7 mediated activity
Nanostarch based nanoencapsulation of Mucuna pruriens extract and its evaluation as anti-parkinsonian drug
Parkinson's disease is a neurodegenerative disease caused by low dopamine levels in the brain. This study aims to obtain the optimum condition for M. pruriens extract nanoencapsulation in nano starch (NS-MPn) and nanostarch-maltodextrin (NS-MD-MPn), nanocapsules characteristics, and their potential as anti-Parkinsonian drug. The nanoencapsulation process was carried out by ultrasonic method. FTIR, SEM, and TEM carried out the characterization of NS-MPn and NS-MD-MPn nanocapsules. Encapsulation efficiency was evaluated by UV-Vis spectroscopy. SEM and TEM characterization NS-MPn and NS-MD-MPn nanocapsules have non-spherical surface morphology, spherical in shape 234.98 and 90.85 nm, respectively. NS-MPn have 21.35% encapsulation efficiency, meanwhile, NS-MD-MPn has 30.02%
Absolute configuration of 3β-acetoxyolean-11,12-aziridin-28,13-β-olide
The title compound, C32H49NO4, has been isolated from the dichloromethane extract of the stem bark of Garcinia atroviridis Griff. ex T. Anders. Rings A and B, B and C, and C and D are trans-fused, whereas rings D and E are cis-fused. Rings A, B, C and E have slightly distorted chair conformations, while ring D is most heavily distorted towards a half-chair conformation owing to the strain induced by the lactonization. The ester group attached to ring A is in an equatorial position
Synthesis and characterization of hexasubstituted cyclotriphosphazene derivatives with azo linking units
A series of new hexasubstituted cyclotriphosphazene derivatives with azo linking units, 4a-d have been synthesized. The alkylation reaction of 4-acetamidophenol with alkylbromide (heptyl, nonyl, decyl, and dodecyl) formed 1a-d, which were further reduced to form the corresponding intermediates, 2a-d. The diazotization reaction of 2a-d with phenol formed calamitic compounds, 3a-d with the azo group later reacted with hexachlorocyclotriphosphazene (HCCP) to yield the final compounds, 4a-d. The functional groups of all the compounds were determined using Fourier Transform Infrared (FTIR), while their molecular structures were characterized by Nuclear Magnetic Resonance (NMR) spectroscopy. The purity of these compounds was confirmed using CHN elemental analysis. Polarized Optical Microscopy (POM) was used to determine the liquid crystal properties of the synthesized compounds. The rod-like intermediates, 3a-d and the disc-like hexasubstituted final products, 4a-d were found to be non-mesogenic without any liquid crystal properties. The results showed that the introduction of non-mesogenic intermediate sidearms would eventually give non-mesogenic products. All the final compounds showed the clearing temperature in the range of 120-130°C
Absolute configuration of fibaruretin B
The title furanoditerpenoid, known as fibaruretin B (systematic name: 2β,3α-dihydroxy-2,3,7,8α-tetrahydropenianthic acid lactone), C20H24O7, was isolated from the roots of Arcangelisia flava. The absolute configurations at positions 2, 3, 4, 4a, 7, 9, 10a and 10b of fibaruretin B are S, R, S, R, S, S, S and S, respectively. In the crystal structure, the molecules are linked into infinite chains along the c axis by O—H⋯O hydrogen bonds and weak C—H⋯O interactions
In vivo carbon tetrachloride-induced hepatoprotective and in vitro cytotoxic activities of Garcinia hombroniana (seashore mangosteen)
Background: Garcinia hombroniana, known as "manggis hutan" (jungle mangosteen) in Malaysia, is distributed in tropical Asia, Borneo, Thailand, Andaman, Nicobar Islands, Vietnam and India. In Malaysia, its ripened crimson sour fruit rind is used as a seasoning agent in curries and culinary dishes. Its roots and leaves decoction is used against skin infections and after child birth. This study aimed to evaluate in vivo hepatoprotective and in vitro cytotoxic activities of 20% methanolic ethyl acetate (MEA) G. hombroniana bark extract. Materials and methods: In hepatoprotective activity, liver damage was induced by treating rats with 1.0 mL carbon tetrachloride (CCl4)/kg and MEA extract was administered at a dose of 50, 250 and 500 mg/kg 24 h before intoxication with CCl4. Cytotoxicity study was performed on MCF-7 (human breast cancer), DBTRG (human glioblastoma), PC-3 (human prostate cancer) and U2OS (human osteosarcoma) cell lines. 1H, 13C-NMR (nuclear magnetic resonance), and IR (infrared) spectral analyses were also conducted for MEA extract. Results: In hepatoprotective activity evaluation, MEA extract at a higher dose level of 500 mg/kg showed significant (p<0.05) potency. In cytotoxicity study, MEA extract was more toxic towards MCF-7 and DBTRG cell lines causing 78.7% and 64.3% cell death, respectively. MEA extract in 1H, 13C-NMR, and IR spectra exhibited bands, signals and J (coupling constant) values representing aromatic/phenolic constituents. Conclusions: From the results, it could be concluded that MEA extract has potency to inhibit hepatotoxicity and MCF-7 and DBTRG cancer cell lines which might be due to the phenolic compounds depicted from NMR and IR spectra
Synthesis, characterization, cytotoxicity evaluation and molecular docking study of new bis-chalcone, fused-pyrimidine and fused-pyrazoline derivatives
Chemotherapeutic drug resistance and high-risk side effects are common limitations in cancer treatment. Thus, the continuous development of new drugs that target only the cancer cell without affecting the normal cells is needed. The simple structure of the chalcone and the ease of its synthesis showed promising functions. Such compounds have been reported to exhibit diverse pharmacological activities, particularly anticancer. This study involves the design of chalcones 1 and 2 which have been synthesized via Claisen-Schmidt condensation. Further cyclo-condensation reactions of these chalcone compounds has formed five pyrazoline and three pyrimidine derivatives. All the desired derivatives are characterised by FT-IR, 1H-NMR, and 13C-NMR. These derivatives are tested for cytotoxicity against breast cancer cell lines (MCF-7 and MD-MB-231) and normal breast cell lines (MCF-10A). The results emphasized that pyrazoline compounds 1Aii and 1Aiii are showing the minimum inhibition against MCF-7 with the IC50 values of56.73±3.3 µM and 37.74±1.32 µM, respectively, after 24 h of exposure, which are comparable to Tamoxifen, as reference anticancer drug (IC50 = 42.66±2.19 µM)