Octadecanedioic acid

We describe the design, synthesis, and antitumor activity of an 18 carbon α,ω-dicarboxylic acid monoconjugated via an ester linkage to paclitaxel (PTX). This 1,18-octadecanedioic acid-PTX (ODDA-PTX) prodrug readily forms a noncovalent complex with human serum albumin (HSA). Preservation of the terminal carboxylic acid moiety on ODDA-PTX enables binding to HSA in the same manner as native long-chain fatty acids (LCFAs), within hydrophobic pockets, maintaining favorable electrostatic contacts between the ω-carboxylate of ODDA-PTX and positively charged amino acid residues of the protein. This carrier strategy for small molecule drugs is based on naturally evolved interactions between LCFAs and HSA, demonstrated here for PTX. ODDA-PTX shows differentiated pharmacokinetics, higher maximum tolerated doses and increased efficacy in vivo in multiple subcutaneous murine xenograft models of human cancer, as compared to two FDA-approved clinical formulations, Cremophor EL-formulated paclitaxel (crPTX) and Abraxane (nanoparticle albumin-bound (nab)-paclitaxel).

Objective: To investigate the effects of Pinggan Prescription (, PGP) on hypertension by the associated methods of metabonomic and pharmacodynamic. Methods: A total of 32 male spontaneously hypertensive rats (SHRs) were randomly divided into two groups by using the random number table method: a treatment group (n=18) and a model group (n=14). The Wistar rats (n=14) were used as the normal group. Different prescription were used to intervene three groups: the treatment group in which PGP extract was administered orally at a dose of 18.336 g/kg (PGP/body weight), and the model group in which physiological saline was administered at the equivalent dose. The same treatment was applied to the normal group as the model group. The blood pressure was measured by tail-cuff method, and pharmacodynamic indexes including cyclic adenosine monophosphate (cAMP) and angiotensin II (Ang II) were tested by enzyme-linked immunosorbent assay. The plasma samples from three groups were detected by gas chromatography-mass spectrometry (GC-MS). Results: Compared with the model group, blood pressure of treatment group was obviously reduced after continuous curing with PGP (P<0.01). The pharmacodynamic results illustrated that the content of Ang II increased with the raised blood pressure and the cAMP expressed the converse trend. After curing with PGP, the content of Ang II decreased, the difference between model group and treatment group was significant (P<0.01), and the cAMP expressed the converse trend. Five potential biomarkers were identified, including arachidonic acid, hexadecanoic acid, elaidic acid, octadecanedioic acid and 9,12-octadecadienoic acid. These metabolites had shown significantly changes as followed: arachidonic acid, hexadecanoic acid and elaidic acid were significantly higher and octadecanedioic acid and 9,12-octadecadienoic acid were lowered in the model group than those in the normal group. After the treatment of PGP, the metabolites had the trends of returning to normal along with the reduced blood pressure. Conclusions: PGP intervention for hypertension played a major role in the metabolism of arachidonic acid and linoleic acid. Metabonomic with pharmacodynamic methods could be potentially powerful tools to investigate the mechanism of Chinese medicine.

A gas chromatographic (GC) method with mass spectrometric (MS) detection is developed and validated for the accurate and precise determination of octadecenedioic acid (C18:1 DIOIC) in human skin samples and transdermal perfusates. C18:1 DIOIC is extracted using methanol. The saturated analogue 1,18-octadecanedioic acid (C18:0 DIOIC) is added as internal standard. Prior to analysis, both compounds are converted to their trimethylsilylated derivatives using N,O-bis(trimethylsilyl)trifluoroacetamide with 15% trimethylchlorosilane. Quantitation is performed in selected ion monitoring mode with a limit of quantitation of 250 ng/mL. Linearity with a correlation coefficient of 0.998 is obtained over a concentration range of 250-2000 ng/mL. Values for within-day accuracy range from 94.5% to 102.4%, and from 97.5% to 105.8% for between-day accuracy. Within- and between-day precision values are better than 5% and 7%, respectively. The recovery values from the various matrices vary from 92.6% to 104.0%. The GC-MS method is employed for the determination of C18:1 DIOIC after application of an emulsion containing the active ingredient onto human skin in vitro. The results demonstrate that the method is suitable for the determination of C18:1 DIOIC in human skin samples and transdermal perfusates.