The LC-MS/MS-Based Measurement of Isopimaric Acid in Rat Plasma and Application of Pharmacokinetics

Isopimaric acid (IPA) exhibits a diverse array of pharmacological activities, having been shown to function as an antihypertensive, antitumor, antibacterial, and hypocholesterolemic agent. However, few studies of the pharmacokinetics of IPA have been performed to date, and such analyses are essential to explore the in vivo mechanisms governing the biological activity of this compound. As such, we herein designed a selective LC-MS approach capable of quantifying serum IPA levels in model rats using an Agilent HC-C18 column ( 250 mm × 4.6 mm , 5 μm) via isocratic elution with a mobile phase composed of methanol 0.5% formic acid (91 : 9, v/v) at a 1 mL/min flow rate. Ion monitoring at m/z 301.2 [M-H]- was used to quantify IPA levels in plasma samples from these rats, while internal standard (IS) levels were assessed at m/z 455.3 [M-H]-. After validation, this approach was employed to conduct a pharmacokinetic analysis of rats administered IPA via the oral (p.o. 50, 100, or 200 mg/kg) and intravenous (i.v. 5 mg/kg) routes. Analyses of noncompartmental pharmacokinetic parameters revealed that IPA underwent secondary absorption following oral administration to these animals, with the two tested oral doses (50 and 100 mg/kg) being associated with respective absolute bioavailability values of 11.9% and 17.5%. In summary, this study may provide a foundation for future efforts to explore the mechanistic basis for the pharmacological activity of IPA, offering insights to guide its subsequent clinical utilization.

Synthesis and biological activity of aldehyde derivatives of isopimaric acid

: Four series of acylhydrazone derivatives, including halogenated aryl modified acylhydrazone, thiophene, pyrrole and quinoline, were synthesized and characterized. The minimum inhibitory concentrations of the compounds against five bacteria were determined and most of the compounds displayed some degree of antibacterial activity. Isopimaric acid (pyrrole-3-carboxaldehyde) acylhydrazone (3j) exhibited the most potent activity against Streptococcus pneumonia and Klebsiella Pneumonia, with the minimum inhibitory concentration being 3.91 μg/mL. The antimicrobial activity against S. pneumoniae was improved when the pyrrole structure was introduced into isopimaric acid. All heterocyclic acylhydrazone derivatives of isopimaric acid exhibited a good in vitro antitumorial activity at 100 μM. It is concluded that the inhibitory effect of isopimaric acid (2-fluoro-6-methoxybenzaldehyde) acylhydrazone (3d) on Hep G2 and isopimaric acid (3-bromothiophene-2-carbaldehyde) acylhydrazone (3g) on Hep G2 and MDAMB 231 is better than that of the positive control 5-fluorouracil (5-FU) (76.51%), which is a widely used clinical anticancer agent, at 100 μM.

Norway Spruce Balm: Phytochemical Composition and Ability to Enhance Re-epithelialization In Vitro

The balm of the Norway spruce (Picea abies) is a well-known traditional herbal medicine used to cure wounds. Even though clinical trials have confirmed its empirical use, the active constituents, their mode of action, and the exact composition of this natural product are still unknown. In this study, the balm was subjected to fractionated extraction and further purified employing flash chromatography, HPLC-PDA-ELSD, preparative and analytical TLC. Hydroxycinnamic acids ( 1– 3), the lignan pinoresinol ( 4), four hydroxylated derivatives of dehydroabietic acid (DHAA) ( 5 – 8), and dehydroabietic acid ( 9) were isolated. Their structures were elucidated by LC-MS, 1D- and 2D-NMR. Four extracts, two commercially available resin acids–pimaric acid ( 10) and isopimaric acid ( 11)–and the isolated compounds were tested for increased re-epithelialization of cell-free areas in a human adult low calcium high temperature keratinocytes monolayer. Lysophosphatidic acid (10 µM) served as positive control and ranged between 100% and 150% rise in cell-covered area related to the vehicle control. Two extracts containing carboxylic acids and non-acidic apolar constituents, respectively, boosted wound closure by 47% and 36% at 10 and 3 µg/mL, respectively. Pinoresinol, DHAA, three of its hydroxylated derivatives, and pimaric and isopimaric acid as well as defined combinations of the hydroxylated DHAA derivatives led to a significantly enhanced wound closure by up to 90% at concentrations between 1 and 10 µM. Overall, lignans and diterpene resin acids, main constituents of Norway spruce balm, are able to increase migration or proliferation of keratinocytes in vitro. The presented data link the phytochemistry of this natural wound healing agent with boosted re-epithelialization.

New Labdanes with Antimicrobial and Acaricidal Activity: Terpenes of Callitris and Widdringtonia (Cupressaceae)

In spite of the evidence for antimicrobial and acaricidal effects in ethnobotanical reports of Callitris and Widdringtonia, the diterpene acids from Widdringtonia have never been described and no comparison to the Australian clade sister genus Callitris has been made. The critically endangered South African Clanwilliam cedar, Widdringtonia wallichii (syn. W. cedarbergensis), of the Cederberg Mountains was once prized for its enduring fragrant timbers and an essential oil that gives an aroma comparable to better known Mediterranean cedars, predominantly comprised by widdrol, cedrol, and thujopsene. In South Africa, two other ‘cedars’ are known, which are called W. nodiflora and W. schwarzii, but, until now, their chemical similarity to W. wallichii has not been investigated. Much like Widdringtonia, Callitris was once prized for its termite resistant timbers and an ‘earthy’ essential oil, but predominantly guaiol. The current study demonstrates that the essential oils were similar across all three species of Widdringtonia and two known non-volatile diterpene acids were identified in leaves: the pimaradiene sandaracopimaric acid (1) and the labdane Z-communic acid (2) with a lower yield of the E-isomer (3). Additionally, in the leaves of the three species, the structures of five new antimicrobial labdanes were assigned: 12-hydroxy-8R,17-epoxy-isocommunic acid (4), 8S-formyl-isocommunic acid (5), 8R,17-epoxy-isocommunic acid (6), 8R-17R-epoxy-E-communic acid (7), and 8R-17-epoxy-E-communic acid (8). Australian Callitris columellaris (syn. C. glaucophylla) also produced 1 and its isomer isopimaric acid, pisiferal (9), and pisiferic acid (10) from its leaves. Callitris endlicheri (Parl.) F.M.Bailey yielded isoozic acid (11) as the only major diterpene. Diterpenes 4–6, pisiferic acid (10), spathulenol, and guaiol (12) demonstrated antimicrobial and acaricidal activity.

THE SIBERIAN LARCH GROUP COMPOSITION AND ACID NEEDLES AT DIFFERENT VEGETATION PERIODS

The research results of the Siberian larch needle extractives are presented in paper. The content of extractive substances from green and yellow needles extracted by organic solvents with different polarities is determined. It is found out that the double increase of the yellow needle extractive substances content soluble in hydrocarbon extractant is observed, whereas it is decreased by 30 per cent when extracted with propan-2-ol. The group composition of needle extracts derived from isopropanol extract by petroleum ether is determined. The neutral substances content in both needle collections is practically the same, although the yellow needles contain less acid “bound” in the form of esters. There is a high content of waxes in the needles, which mainly consist of secondary nonacosanol-10 alcohol. The composition of free and “bound” acids in Siberian larch needles of different vegetation periods is established. The needles are dominated by groups of higher unsaturated C-18 fatty acids. Resin acids are represented by isopimaric acid (isopimaric and sandaracopimaric) and abietic acids: abietic, dehydroabietic and levopiric acids. In yellow needles, the content of dehydroabietic acid is increased quadrupled and the hydroxy acids are identified: 15-hydroxyabietic acid and 15-hydroxyhydroabietic acid. The tri- and tetraenic C-20 acids are identified among higher fatty acids.