ABSTRACT
Four new 8,9,30-phragmalin orthoesters (1-4), along with six related known compounds, namely xyloccensins O-S (5-9) and V (10), were isolated and characterized from the twigs and leaves of the Chinese mangrove Xylocarpus granatum. The structures of the new compounds were determined on the basis of extensive spectroscopic analysis and by comparison with those of related known compounds in the literature. The absolute configuration of xyloccensin Q (7) was revised as its enantiomer by X-ray diffraction analysis employing graphite monochromated Cu Kα radiation (λ=1.54178 Å) with a Flack parameter of -0.04 and was further secured by a time-dependent density functional theory electronic circular dichroism (TDDFT ECD) calculation. Consequently, the absolute configurations of xyloccensins O (5), P (6), R (8), S (9), and V (10) were all corrected as their corresponding enantiomers, respectively. Xyloccensin S (9) exhibited inhibitory activity against protein tyrosine phosphatase 1B, a potential drug target for the treatment of type II diabetes and obesity, with an IC50 value of 8.72 µg/mL.
Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Esters/pharmacology , Limonins/pharmacology , Meliaceae/chemistry , Crystallography, X-Ray , Esters/chemistry , Esters/isolation & purification , Humans , Inhibitory Concentration 50 , Limonins/chemistry , Limonins/isolation & purification , Magnetic Resonance Spectroscopy , Molecular Structure , Plant Leaves/chemistry , Plant Stems/chemistry , Plants, Medicinal , Protein Tyrosine Phosphatase, Non-Receptor Type 1/antagonists & inhibitorsABSTRACT
A series of previously unreported compounds including seven new apotirucallane protolimonoids, xylogranatumines A-G (1-7), were isolated together with three known analogues (8-10) from the twigs and leaves of the Chinese mangrove, Xylocarpus granatum. The structures of these new compounds were elucidated by extensive spectroscopic analysis including 1D and 2D NMR and high-resolution electrospray ionization mass spectrometry (HRESIMS) and by comparison with those of related known compounds in the literature. Xylogranatumine F (6) exhibited cytotoxic activity against A549 tumor cell in vitro.
Subject(s)
Meliaceae/chemistry , Triterpenes/isolation & purification , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Molecular Structure , Triterpenes/chemistryABSTRACT
Two new C-15-acyl phragmalin limonoids, velutinalides A and B, featuring a C-16/C-30 δ-lactone ring, and a new structurally related natural product, R310B8, were isolated from the leaves of Chukrasia tabularis var. velutina. Their structures were elucidated on the basis of extensive spectroscopic data analyses and by comparison of their NMR data with those of related known compounds.
Subject(s)
Limonins/chemistry , Meliaceae/chemistry , China , Limonins/isolation & purification , Nuclear Magnetic Resonance, Biomolecular , Plant Leaves/chemistryABSTRACT
Six new tirucallane protolimonoids, toonapubesins A-F (1-6), one new rearranged tirucallane protolimonoid, toonapubesin G (7), and two new 21,22,23-trinorapotirucallane limonoids, toonapubesic acids A (8) and B (9), possessing an unprecedented carbon skeleton, along with five known tirucallane protolimonoids (10-14) and one known apotirucallane limonoid (15), were isolated from the stem bark of Toona ciliata var. pubescens. Their structures and relative configurations were determined by detailed spectroscopic analysis and by chemical methods. The proposed structures of 8 and 11 were confirmed by X-ray diffraction analysis of their respective derivatives (8a and 11a). The absolute configuration of 8 was determined by a novel solid-state TDDFT ECD approach on its derivative 8a while the absolute configuration of 10 was determined by the modified Mosher's method. In addition, the structures of dyvariabilin H (10c) proposed by Sticher et al. and cneorin-NP(36) (11b) by Mondon et al. were corrected as 10 and 11, respectively. Toonapubesin G (7) showed promising inhibitory activity against CDC25B with an IC(50) value of 2.1 µM, while compound 8a showed significant cell protecting activity against H(2)O(2)-induced SH-SY5Y cell damage with 11.5% increase in cell viability.
Subject(s)
Chemistry, Pharmaceutical/methods , Drugs, Chinese Herbal/chemistry , Limonins/chemistry , Meliaceae/chemistry , cdc25 Phosphatases/antagonists & inhibitors , Cell Line, Tumor , Cell Survival/drug effects , Crystallography, X-Ray , Drugs, Chinese Herbal/pharmacology , Humans , Hydrogen Peroxide/adverse effects , Limonins/classification , Limonins/isolation & purification , Limonins/pharmacology , Molecular Structure , Neuroblastoma/drug therapy , Neuroblastoma/pathology , Nuclear Magnetic Resonance, Biomolecular , Oxidative Stress/drug effects , Plant Bark/chemistry , Plant Stems/chemistry , cdc25 Phosphatases/metabolismABSTRACT
Five new pregnane steroids, toonasterones A (1), B (2), (Z)-aglawone (3), (Z)-toonasterone C (4), and (E)-toonasterone C (5), were isolated from the stem bark of Toona ciliata var. pubescens. Their structures were elucidated by means of detailed spectroscopic (IR, MS, and 2D NMR) analysis, and the stereochemistry of 1 was secured by X-ray diffraction analysis. (Z)-aglawone (3) exhibited moderate inhibitory activity of protein tyrosine phosphatase 1B (PTP1B), a potential drug target for treatment of type-II diabetes and obesity, with an IC(50) value of 1.12 µg/mL.
Subject(s)
Enzyme Inhibitors/chemistry , Plant Bark/chemistry , Plant Extracts/chemistry , Pregnanes/chemistry , Sapindaceae , Binding, Competitive , Crystallography, X-Ray , Enzyme Inhibitors/isolation & purification , Molecular Conformation , Plant Extracts/isolation & purification , Pregnanes/isolation & purification , Protein Tyrosine Phosphatase, Non-Receptor Type 1/antagonists & inhibitors , StereoisomerismABSTRACT
A new diphenacyl-piperidine alkaloid, sonneratine A (2), identified as a piperidine ring bearing two phenacyl substitutes at C-2 and C-6, and a known related derivative, (+/-)1-(2-piperidyl)-4-( P-methoxyphenyl)-butanone-2 (3), were isolated from the leaves and stems of the Hainan mangrove Sonneratia hainanensis. The structure of the new compound was determined by extensive analysis of its spectroscopic data and by comparison of its NMR data with those reported in the literature.