16-O-Methylcafestol
(Synonyms: 16-O-甲基咖啡醇) 目录号 : GC40395A diterpene
Cas No.:108214-28-4
Sample solution is provided at 25 µL, 10mM.
Quality Control & SDS
- View current batch:
- Purity: >98.00%
- COA (Certificate Of Analysis)
- SDS (Safety Data Sheet)
- Datasheet
16-O-Methylcafestol is a diterpene that has been found in robusta (C. canephora) coffee beans. It has been used as a marker for robusta contamination and or adulteration of Arabica (C. arabica) roast coffee grounds in commercial production.
Cas No. | 108214-28-4 | SDF | |
别名 | 16-O-甲基咖啡醇 | ||
Canonical SMILES | OC[C@@]1(OC)C[C@]23[C@](CC[C@]1([H])C3)([H])[C@@](CCC4=C5C=CO4)(C)[C@]5([H])CC2 | ||
分子式 | C21H30O3 | 分子量 | 330.5 |
溶解度 | DMF: 12 mg/mL,DMF:PBS (pH 7.2) (1:50): 0.02 mg/mL,DMSO: 5 mg/mL,Ethanol: 5 mg/mL | 储存条件 | Store at -20°C |
General tips | 请根据产品在不同溶剂中的溶解度选择合适的溶剂配制储备液;一旦配成溶液,请分装保存,避免反复冻融造成的产品失效。 储备液的保存方式和期限:-80°C 储存时,请在 6 个月内使用,-20°C 储存时,请在 1 个月内使用。 为了提高溶解度,请将管子加热至37℃,然后在超声波浴中震荡一段时间。 |
||
Shipping Condition | 评估样品解决方案:配备蓝冰进行发货。所有其他可用尺寸:配备RT,或根据请求配备蓝冰。 |
制备储备液 | |||
1 mg | 5 mg | 10 mg | |
1 mM | 3.0257 mL | 15.1286 mL | 30.2572 mL |
5 mM | 0.6051 mL | 3.0257 mL | 6.0514 mL |
10 mM | 0.3026 mL | 1.5129 mL | 3.0257 mL |
第一步:请输入基本实验信息(考虑到实验过程中的损耗,建议多配一只动物的药量) | ||||||||||
给药剂量 | mg/kg | 动物平均体重 | g | 每只动物给药体积 | ul | 动物数量 | 只 | |||
第二步:请输入动物体内配方组成(配方适用于不溶于水的药物;不同批次药物配方比例不同,请联系GLPBIO为您提供正确的澄清溶液配方) | ||||||||||
% DMSO % % Tween 80 % saline | ||||||||||
计算重置 |
计算结果:
工作液浓度: mg/ml;
DMSO母液配制方法: mg 药物溶于 μL DMSO溶液(母液浓度 mg/mL,
体内配方配制方法:取 μL DMSO母液,加入 μL PEG300,混匀澄清后加入μL Tween 80,混匀澄清后加入 μL saline,混匀澄清。
1. 首先保证母液是澄清的;
2.
一定要按照顺序依次将溶剂加入,进行下一步操作之前必须保证上一步操作得到的是澄清的溶液,可采用涡旋、超声或水浴加热等物理方法助溶。
3. 以上所有助溶剂都可在 GlpBio 网站选购。
16-O-Methylcafestol is present in ground roast Arabica coffees: Implications for authenticity testing
Food Chem 2018 May 15;248:52-60.PMID:29329870DOI:10.1016/j.foodchem.2017.12.034.
High-field and low-field proton NMR spectroscopy were used to analyse lipophilic extracts from ground roast coffees. Using a sample preparation method that produced concentrated extracts, a small marker peak at 3.16 ppm was observed in 30 Arabica coffees of assured origin. This signal has previously been believed absent from Arabicas, and has been used as a marker for detecting adulteration with robusta. Via 2D 600 MHz NMR and LC-MS, 16-O-Methylcafestol and 16-O-methylkahweol were detected for the first time in Arabica roast coffee and shown to be responsible for the marker peak. Using low-field NMR, robusta in Arabica could be detected at levels of the order of 1-2% w/w. A surveillance study of retail purchased "100% Arabica" coffees found that 6 out of 60 samples displayed the 3.16 ppm marker signal to a degree commensurate with adulteration at levels of 3-30% w/w.
Screening for 16-O-Methylcafestol in roasted coffee by high-performance thin-layer chromatography-fluorescence detection - Determination of Coffea canephora admixtures to Coffea arabica
J Chromatogr A 2017 Nov 24;1525:173-180.PMID:29042111DOI:10.1016/j.chroma.2017.10.031.
16-O-Methylcafestol (16-OMC), the characteristic diterpene exclusively present in Coffea canephora, is an excellent marker for Coffea canephora admixtures to Coffea arabica. Here we show a straightforward, selective and sensitive screening method for the determination of 16-OMC in roasted coffee by high-performance thin-layer chromatography with fluorescence detection (HPTLC-FLD). As internal standard, Sudan IV was used, and a direct saponification with 10% ethanolic potassium hydroxide solution was followed by solid supported liquid extraction with petroleum ether. 16-OMC was selectively derivatized with 2-naphthoyl chloride and analyzed by HPTLC-FLD on silica gel plates with cyclohexane/tert-butyl methyl ether/formic acid (86:14:2, v/v/v) as the mobile phase. The enhanced fluorescence was scanned at UV 244/>320nm. Limits of detection and quantitation of 5 and 14mg 16-OMC/kg coffee allowed the determination of Coffea canephora admixtures to Coffea arabica below 1%. Recoveries for blends of Coffea arabica with Coffea canephora were close to 100%.
16-O-Methylated diterpenes in green Coffea arabica: ultra-high-performance liquid chromatography-tandem mass spectrometry method optimization and validation
J Mass Spectrom 2020 Nov;55(11):e4636.PMID:32767433DOI:10.1002/jms.4636.
Coffee diterpenes are the main constituents of the coffee oil unsaponifiable fraction. The three most important diterpenes are cafestol, kahweol, and 16-O-Methylcafestol (16-OMC), and they are produced, except for cafestol, only by plants of the Coffea genus. Recently, in addition to these three major diterpenes, another 16-O-methylated diterpene (16-O-methylkahweol: 16-OMK) has been identified and quantified, for the first time, in Robusta coffee. For many years, 16-OMC has been considered present exclusively in Robusta, and so it has been reputed an excellent authenticity marker for the presence of Robusta in coffee products. For its quantification, nuclear magnetic resonance (NMR) has proved very useful when compared with other methods. Quite recently, the detection of very low levels of the two 16-O-methylated diterpenes (16-OMD) 16-OMC and 16-OMK in roasted Arabica was reported. This finding makes the use of NMR methods in 16-OMD quantification in Arabica coffee particularly challenging in view of both the trace amounts of 16-OMD and the impossibility to discriminate between 16-OMC and 16-OMK. The ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS) method, already used to detect 16-OMC and 16-OMK in Arabica roasted coffee, is then more suitable for quantitative analyses. Up to now however, no quantification of coffee 16-OMD via ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) has been carried out; this largely stimulated the present study. For the first time, a simple procedure for the quantitative detection of 16-OMD in Arabica coffee has been developed, and as far as 16-OMC is concerned, fully validated in terms of specificity, linearity, concentration range, limit of detection (LOD), limit of quantification (LOQ), and repeatability following the criteria specified in the EU Commission Decision 2002/675/EC. This method proved to be very specific and sensitive. In order to avoid the chemical complexity generated by the roasting process, the method was optimized and validated on several green Arabica samples from different geographical origins.
Interaction of the Coffee Diterpenes Cafestol and 16- O-Methyl-Cafestol Palmitates with Serum Albumins
Int J Mol Sci 2020 Mar 6;21(5):1823.PMID:32155814DOI:10.3390/ijms21051823.
The main coffee diterpenes cafestol, kahweol, and 16-O-Methylcafestol, present in the bean lipid fraction, are mostly esterified with fatty acids. They are believed to induce dyslipidaemia and hypercholesterolemia when taken with certain types of coffee brews. The study of their binding to serum albumins could help explain their interactions with biologically active xenobiotics. We investigated the interactions occurring between cafestol and 16-O-Methylcafestol palmitates with Bovine Serum Albumin (BSA), Human Serum Albumin (HSA), and Fatty Free Human Serum Albumin (ffHSA) by means of circular dichroism and fluorimetry. Circular Dichroism (CD) revealed a slight change (up to 3%) in the secondary structure of fatty-free human albumin in the presence of the diterpene esters, suggesting that the aliphatic chain of the palmitate partly occupies one of the fatty acid sites of the protein. A warfarin displacement experiment was performed to identify the binding site, which is probably close but not coincident with Sudlow site I, as the affinity for warfarin is enhanced. Fluorescence quenching titrations revealed a complex behaviour, with Stern-Volmer constants in the order of 103-104 Lmol-1. A model of the HSA-warfarin-cafestol palmitate complex was obtained by docking, and the most favourable solution was found with the terpene palmitate chain inside the FA4 fatty acid site and the cafestol moiety fronting warfarin at the interface with site I.
Rapid authentication of coffee blends and quantification of 16-O-Methylcafestol in roasted coffee beans by nuclear magnetic resonance
J Agric Food Chem 2014 Dec 24;62(51):12309-14.PMID:25431971DOI:10.1021/jf505013d.
Roasted coffee is subject to commercial frauds, because the high-quality Coffea arabica species, described as "100% Arabica" or "Highland coffee", is often mixed with the less expensive Coffea canephora var. Robusta. The quantification of 16-O-Methylcafestol (16-OMC) is useful to monitor the authenticity of the products as well as the Robusta content in blends. The German standard method DIN 10779 is used in the determination of 16-OMC in roasted coffee beans to detect C. canephora in blends, but it is laborious and time-consuming. Here, we introduce a new method that provides a quantitative determination of esterified 16-OMC directly in coffee extracts by means of high-resolution proton nuclear magnetic resonance spectroscopy. Limit of detection and limit of quantitation were 5 and 20 mg/kg, respectively, which are adequate to detect the presence of Robusta at percentages lower than 0.9%. The proposed method is much faster, more sensitive, and much more reproducible than the DIN standard method.