Search

Context: Prunus serotina Ehrenb. subsp. capuli (Cav.) McVaugh (Rosaceae), commonly known as "capulin", is a native North American tree, commercialized and used in folk medicine for the treatment of the hypertension, gastrointestinal illnesses, and cough., Objective: This work developed a suitable HPLC method for quantifying the major active constituents of the infusion of P. serotina, the most important preparation consumed by populations around the world., Materials and Methods: The analytical method was performed using a Fortis-RP column (150 mm × 4.6 mm; film thickness 5 µm). The mobile phase consisted of an isocratic acetate buffer solution (pH 2.7; A) and methanol (B) (65:35 v/v) at a flow rate of 1.0 mL min(-1)., Results: The proposed method was applied to the quantification of 1-3 in several samples of the leaves of P. serotina. The results indicated that amounts of 1-3 in the samples analyzed are uniform, and greater amounts of chlorogenic acid (2; 479.9 ± 33.6 µg g(-1), dry matter) along with hyperoside (1; 185.7 ± 55.3 µg g(-1), dry matter) were present. On the other hand, benzaldehyde (3; 118.2 ± 12.1 µg g(-1) dry matter) was found to be in lower concentration., Conclusions: A simple, sensitive, precise, and reproducible HPLC method for the simultaneous quantification of 1-3 in P. serotina was developed and validated. This is the first report on the quantification of 1-3 as active principles, and compound 1 was selected as a marker of P. serotina, which could be useful to guarantee the quality of the crude drug and herbal products.

Bioassay guided fractionation of an antimycobacterial extract of Arracacia tolucensis var. multifida (Umbelliferae) led to the isolation of isoimperatorin (1), osthol (2), suberosin (3), 8-methoxypsoralen (8-MOP) (4), herniarin (5), scoparone (6), umbelliferone (7), dihydroxypeucedanin (8), 5-methoxypsoralen (5-MOP) (9), isoscopoletin (10) and scopoletin (11). The isolates were tested against Mycobacterium tuberculosis and only 1-4 showed significant activity with MIC values of 64, 32, 16 and 128 microg/mL, respectively. The essential oil showed moderate in vitro antibacterial activity against representative Gram-positive and Gram-negative bacteria. The volatile oil of Arracacia tolucensis var. multifida was analyzed by GC-MS and found to be composed mainly by 2 and 3. The essential oil (IC(50)=116.4+/-23.2 microg/mL) and the extract (IC(50)=1153.1+/-53.2 microg/mL) of the plant provoked concentration dependent inhibition of the tone and amplitude of the guinea-pig ileum spontaneous contractions; the latter activity was related with the high coumarin content of this species. A suitable (novel and rapid) HPLC method to quantify the major active coumarins of the plant was developed. The method provides also a reproducible fingerprint useful for identity tests of this plant.

The present investigation describes the effect of the spasmolytic benzylbenzoates 1-9 from Brickellia veronicifolia on CaM using a functional in vitro enzymatic assay. Bovine brain PDE1 was used as a monitoring enzyme. The most active natural inhibitors of the system CaM-PDE1 were benzyl benzoates 3-5, which inhibited the activity of PDE1 in a concentration-dependent manner. In addition, three series of analogs of compound 4, compounds 10a-32a, were prepared and assayed. The benzyl benzoates from the first series, namely 10a-24a, possess no substituents on ring B but different number and position of hydroxyl or methoxy groups in ring A. The second group (25-32a), on the other hand, possesses an A ring identical to that on compound 4, but different substituents in Ring B. The most active compounds were 14a, 15a and 30a. These compounds were two to six times more potent than chlorpromazine, a well known CaM inhibitor. Benzyl benzoates 14a and 15a have methoxyl groups at C-2/C-4 and C-3/C-4 in ring A, respectively; while 30a, in addition to the methoxyl groups at C-2/C-6 of ring A, hold a benzoyloxy moiety at C-3' of ring B. Kinetic studies revealed that compounds 3, 4, 14a, 15a and 30a behave as competitive CaM antagonists.

The composition of the spasmolytic essential oil of the medicinal species Brickellia veronicaefolia was established by NMR spectroscopy in addition to GC-MS analysis and HPLC studies. Seven major compounds, representing ca. 86% of the oil, were identified as benzyl 2,6-dimethoxybenzoate (1), 2-hydroxybenzyl 2'-methoxybenzoate (2), chamazulene (3), beta-caryophyllene (4), germacrene D (5), bicyclogermacrene (6), and beta-eudesmol (7). A sensitive and accurate analytical 1H NMR method has been developed for the quantification of the major compounds in the essential oil of B. veronicaefolia. The method was validated using benzyl 2,6-dimethoxybenzoate (1) and beta-caryophyllene (4), two of the active principles in the oil, and successfully applied to the determination of these pharmacologically active compounds in three different batches of the oil collected in different geographical regions and/or seasons.

A dichloromethane-MeOH extract prepared from the aerial parts of Brickellia veronicaefolia inhibited the spontaneous contractions (IC50 = 39.22 microg/mL) of the guinea-pig ileum. Bioassay-guided fractionation of the extract led to the isolation of three new benzoic acid derivatives, 1,2-bis-O-(2-methoxybenzoyl)-beta-d-glucopyranoside (1), 3-(beta-glucopyranosyloxy)benzyl 2,6-dimethoxybenzoate (2) and 3-hydroxybenzyl 2,6-dimethoxybenzoate (3), together with the known compounds taraxasteryl acetate (4), 4-allyl-2-methyloxyphenyl-beta-glucopyranoside (5), 2-hydroxy-6-methoxybenzoic acid (6), 2-methoxybenzoic acid (7), chamazulene (8), 2-methoxybenzyl 2-hydroxybenzoate (9), benzyl 2,6-dimethoxybenzoate (10), 3-methoxybenzyl 2-hydroxy-6-methoxybenzoate (11), benzyl 2-hydroxy-6-methoxybenzoate (12), benzyl 2,3,6-trimethoxybenzoate (13), benzyl 2-hydroxy-3,6-dimethoxybenzoate (14) and 3-methoxybenzyl 2,6-dimethoxybenzoate (15). The isolates were characterized by spectral means. Compounds 2 - 6, 8 - 11, 14 and 15 induced a concentration-dependent inhibition of the spontaneous contractions of the guinea-pig ileum with IC50 values ranging from 1.49 to 4.96 microM. Their activity was comparable to that of papaverine (IC50 = 4.23 microM).