高效液相色谱-质谱法测定沙田柚果肉汁中的呋喃香豆素类化合物

采用反相高效液相色谱法,以C18硅胶柱为色谱柱,甲醇-水(含0.1%HAc)为流动相,梯度洗脱分离了沙田柚果肉汁的正己烷和乙酸乙酯提取物,电喷雾质谱确证了沙田柚果肉汁中6种结构相近的呋喃香豆素类化合物的结构,它们分别为6′,7′-二羟基香柠檬素(6′,7′-dihydroxybergamottin)、香柠檬素(bergamottin)、5-甲氧基呋喃香豆素(bergapten)、5-甲氧基-8-异戊烯氧基呋喃香豆素(phellopterin)、6′,7′-环氧香柠檬素(6′,7′-epoxybergamottin)及二聚体对氧呋喃香豆素-6′,7′-二羟基香柠檬素(FC574)。

Breeding and Analysis of Two New Grapefruit-Like Varieties with Low Furanocoumarin Content

Furanocoumarins (FCs) are a group of related plant defense metabolites occurring in several plant families, including some species in the genus citrus, such as grapefruit and pummelo. FCs function as toxins against pathogens, insects and other plant pests and some are toxic to humans at high levels. Although the levels of FCs in grapefruits are non-toxic to humans, they inhibit the intestinal enzyme CYP3A, thus preventing degradation of medicines, such as statins, and causing dangerous overdose effects. This overdosing can cause devastating side effects, ranging from stomach bleeding to kidney problems, muscle aches and irregular heartbeats. In the present study, we utilize LC/MS to characterize the levels of FCs pathway intermediates and end products in twelve citrus cultivars, including mandarin (Citrus reticulata), orange [Citrus sinensis (L.) Osbeck], Pummelo [Citrus maxima (Burm.) Merr.], grapefruit (Citrus paradisi Macf.), and two newly selected grapefruit like varieties [(Citrus reticulate) X [Citrus maxima (Burm.) Merr]. The orange and mandarin varieties do not contain FCs or FCs precursor compounds suggesting that this biosynthetic pathway is absent or inactive in mandarins and oranges and therefore a good genetic source for null alleles to FCs biosynthesis. We report the selection and characterization of two new low FCs and seedless grapefruit-like varieties, “Aliza” and “Coocki”, developed by a cross between pummelo and mandarin. Fruits of these varieties resemble grapefruit and contain high levels of the flavanone naringin, typical of grapefruit, but contain only trace amounts of FCs (based on LCMS analysis). Based on the variability of FCs content and inheritance in citrus species, the results suggest that future development of new low-FCs grapefruit varieties is an achievable objective.

A new dimeric furanocoumarin from Notopterygium incisum

A new dimeric psoralen-type furanocoumarin, notopterol-（18-O-20＇）-notopol （1）, was isolated from Notopterygium incisum for the first time and its structure was elucidated by spectroscopic methods.

Structural, Thermal and Optical Studies of Oxypeucedanin Hydrate Monoacetate Micro-Crystals from <i>Prangos pabularia</i>

Oxypeucedanin hydrate monoacetate (Mol. Formula = C18H18O7) micro-crystals were obtained by acetylation of oxy-peucedanin hydrate, a furanocoumarin, isolated from the roots of Prangos pabularia. The composition related structural, thermal and optical properties were investigated. All the crystals were found to have triclinic structure. From thermal studies of these crystals, stability, melting point and other relevant informations were obtained. Their blue emission, less absorption in entire visible range and band gap predicts these crystals as good candidate for modern optoelectronic devices.

A theoretical study on the molecular structure and chemical reactivity of traditional Chinese medicine extract isopimpinellin

Isopimpinellin(C13H10O5),alternative name 5,8-dimethoxypsoralen,is one of the furocoumarin compounds.This traditional Chinese medicine extract has attracted a great deal of attention in recent years due to its pharmacological properties,especially its antifungal effect.The main purpose of this study was to study the molecular structure and chemical reactivity of isopimpinellin using the density functional theory method.To understand and interpret the reactivity of isopimpinellin,various chemical reactivity descriptors such as chemical potential(μ),electronegativity(χ),chemical hardness(η)and electrophilicity(ω)and local reactivity index condensed Fukui function(fi(r))have been calculated with five hybrid functionals PBE1PBE,MPW1PW91,B3LYP,X3LYP and B3PW91.These chemical reactivity descriptors indicate that the isopimpinellin molecule has a good antioxidant activity,which could be one of the reasons for its action as an effective antifungal drug.The condensed Fukui functions of isopimpinellin molecule provide a complete scheme of chemical reactivity of one molecule.

Solid Tumor Inhibitory and other Constituents of Casimiroa tetrameria

AIM:To isolate and characterize solid tumor inhibitory and other constituents from a bioactive extract of Casimiroa tetrameria((Rutaceae).METHODS:A crude extract of C.tetrameria obtained from the US National Cancer Institute Natural Product Repository and found to exhibit selective toxicity to solid tumor cells was subjected bioactivity-guided fractionation involving solvent-solvent partitioning,gel filtration,and chromatography.The structures of all isolated compounds were elucidated by spectroscopic analysis(NMR and MS) and/or by comparison with the reported data.Compounds 1 and 4-9 were evaluated for their solid tumor selective cytotoxicity.RESULTS:Nine metabolites,including a new furanocoumarin,5-methoxy-8-(4'-acetoxy-3'-methylbut-2-eny-loxy)-psoralen(1),and the previously known compounds 2-9 were encountered.Of these the flavonoid zapotin(6),and N-benzoyltyramide derivatives 7 and 8 were found to be the active constituents.CONCLUSION:Zapotin(6) is the most potent constituent of C.tetrameria with solid tumor selectivity.