In search for new metabolites from the stem bark of and , led to the isolation of a new xanthone, soulaxanthone (), along with four other known metabolites, euxanthone (), calopolyanolide E (), calanolide E () and friedelin (). The structures of these compounds were identified and elucidated using spectroscopic techniques such as H NMR,C NMR, COSY, DEPT, HSQC, HMBC, MS and FTIR. The antibacterial activities of compounds -, as well as the extracts, were tested against five bacterial strains.
View Article and Find Full Text PDFCancer has become the primary cause of death worldwide, and anticancer drugs are used to combat this disease. Synthesis of anticancer drugs has limited success due to adverse side effects has made compounds from natural products with minimal toxicity gain much popularity. Piper species are known to have a biological effect on human health.
View Article and Find Full Text PDFEthnopharmacological Relevance: Malaria, a devastating infectious disease which was initially recognized as episodic fever, is caused by parasitic protozoan of the genus Plasmodium. Medicinal plants with ethnobotanical information to treat fever and/or malaria has been the key element in identifying potential plant candidates for antimalarial screening. Goniothalamus lanceolatus Miq.
View Article and Find Full Text PDFEight new bis-styryllactones, goniolanceolatins A-H (-), possessing a rare α,β-unsaturated δ-lactone moiety with a (6)-configuration, were isolated from the CHCl extract of the stembark and roots of Miq., a plant endemic to Malaysia. Absolute structures were established through extensive 1D- and 2D-NMR data analysis, in combination with electronic dichroism (ECD) data.
View Article and Find Full Text PDFProteins have played a very important role in the drug industry for developing treatments of various diseases such as auto-immune diseases, cancer, diabetes, mental disorder, metabolic disease, and others. Therapeutic proteins have high activity and specificity but they have some limitations such as short half-life, poor stability, low solubility and immunogenicity, so they cannot prolong their therapeutic activity. These shortcomings have been rectified by using polymers for the conjugation with proteins.
View Article and Find Full Text PDFThe essential oils from different parts of Litsea cubeba, collected from the highlands of Sarawak, were isolated and their chemical compositions analyzed. This study demonstrated significant variations in the chemical compositions and the chemical profiles of the volatiles and could provide valuable supplementary information on the geographical variations of the species. The fruit essential oil was dominated by citronellal, d-limonene and citronellol, while the leaf oil was high in eucalyptol and a-terpineol.
View Article and Find Full Text PDFObjective: To investigate antioxidant and antimicrobial activities of two plant species, Litsea elliptica (L. elliptica) and Litsea resinosa (L. resinosa).
View Article and Find Full Text PDFFive new organotin(IV) complexes of 2-hydroxyacetophenone-2-methylphenylthiosemicarbazone [H(2)dampt, (1)] with formula [RSnCl(n-1)(dampt)] (where R = Me, n = 2 (2); R = Bu, n = 2 (3); R = Ph, n = 2 (4); R = Me(2), n = 1 (5); R = Ph(2), n = 1 (6)) have been synthesized by direct reaction of H(2)dampt (1) with organotin(IV) chloride(s) in absolute methanol. The ligand (1) and its organotin(IV) complexes (2-6) were characterized by CHN analyses, molar conductivity, UV-Vis, FT-IR, (1)H, (13)C, and (119)Sn NMR spectral studies. H(2)dampt (1) is newly synthesized and has been structurally characterized by X-ray crystallography.
View Article and Find Full Text PDFPhytochemical investigation on the bark of Goniothalamus tapis Miq. and G. uvaroides King has resulted in the isolation of eight styryl-lactones, (-)-cryptomeridiol, liriodenine, 3-methyl-1H-benz[f]indole-4,9-dione, (-)-stigmasterol and dimethyl terephthalate.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
July 2011
The Sn(IV) atom in the title compound, [Sn(CH(3))(2)(C(17)H(14)N(2)O(3))], is five-coordinated within a C(2)N(2)O donor set provided by the N,N,O-tridentate ligand and two methyl groups. The resultant coordination geometry is inter-mediate between trigonal-bipyramidal and square-pyramidal. In the crystal, supra-molecular zigzag chains propagating along the c- axis direction are mediated by O-H⋯O hydrogen bonds, and weak C-H⋯π inter-actions consolidate the packing.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
July 2011
Two independent diphenyl-tin mol-ecules and two independent methanol mol-ecules comprise the asymmetric unit of the title compound, [Sn(C(6)H(5))(2)(C(17)H(14)N(2)O(3))]·CH(3)OH. The Sn atom in each is five-coordinated by a tridentate ligand and the ipso-C atoms of the Sn-bound benzene substituents. The resulting C(2)N(2)O donor set defines a coordination geometry that is inter-mediate between trigonal-bipyramidal (TP) and square-pyramidal (SP), with one mol-ecule slightly tending towards TP and the other slightly towards SP.
View Article and Find Full Text PDFAn HPLC method with ultraviolet-visible spectrophotometry detection has been optimized and validated for the simultaneous determination of phenolic compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as antioxidants, and octyl methyl cinnamate (OMC) as UVB-filter in several personal care products. The dynamic range was between 1 to 250 mg/L with relative standard deviation less than 0.25% (n = 4).
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
May 2011
In the title thio-urea derivative, C(10)H(17)N(3)O(2)S, the carboxyl group and the least-squares plane through the cyclo-hexyl ring are twisted out of the plane through the central CN(3)S residue; the respective dihedral angles are 7.18 (8) and 62.29 (4)°.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
April 2011
In the title thio-urea derivative, C(14)H(20)N(4)S, the non-ring non-H atoms are approximately planar, with an r.m.s.
View Article and Find Full Text PDFNine essential oils, hydrodistilled from different parts of five Goniothalamus species (G. velutinus Airy-Shaw, G. woodii Merr.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
November 2010
The Sn(IV) atom in the title compound, [Sn(C(6)H(5))(C(14)H(19)N(4)S)Cl(2)], exists within a distorted octa-hedral geometry defined by the N,N',S-tridentate monodeprotonated Schiff base ligand, two mutually trans Cl atoms, and the ipso-C atom of the Sn-bound phenyl group; the latter is trans to the azo-N atom. The greatest distortion from the ideal geometry is found in the nominally trans angle formed by the S and pyridyl-N atoms at Sn [151.03 (4)°].
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
October 2010
Two independent mol-ecules comprise the asymmetric unit of the title compound, [Sn(C(4)H(9))(C(13)H(12)N(3)O)Cl(2)]. The Sn atom in each is coordinated by the tridentate ligand via the phenoxide O, hydrazine N and pyridyl N atoms, forming five- and six-membered chelate rings. The approximately octa-hedral coordination geometry is completed by the α-C atom of the n-butyl group (which is trans to the hydrazine N atom) and two mutually trans Cl atoms.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
July 2010
Two independent but very similar mol-ecules comprise the asymmetric unit of the title compound, [Sn(CH(3))(2)(C(18)H(12)N(2)O(3))]. Each Sn atom is coordinated by two methyl groups and two O atoms and an N atom from the dinegative tridentate ligand. The resultant C(2)NO(2) donor set defines a coordination geometry inter-mediate between square-pyramidal and trigonal-pyramidal, with a small tendency towards the former.
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February 2010
In the title compound, C(17)H(18)N(4)O(2)S·H(2)O, the thio-urea derivative is almost planar, with an r.m.s.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
April 2010
The deprotonated Schiff base ligand in the title compound, [Sn(C(4)H(9))(2)(C(18)H(12)N(2)O(3))], O,N,O'-chelates to the Sn atom, which is five-coordinated in a cis-C(2)NO(2)Sn trigonal-bipyramidal environment. The apical sites are occupied by the O atoms [O-Sn-O = 155.2 (2)°].
View Article and Find Full Text PDFThe crude methanol extracts of Gelsemium elegans leaves were assessed for their cytotoxic activity using the microculture 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for cellular viability. This study utilized two different types of human cancer cell lines, CaOV-3 (human ovarian cancer cells) and MDA-MB-231 (human estrogen receptor negative breast cancer cells), allowing for comparison of toxicity of G. elegans against these two cancer cells lines.
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