Antispasmodic activity of essential oil from Lippia dulcis Trev

AIM OF THIS STUDY: To investigate the essential oil of Lippia dulcis Trev. (Verbenaceae) that is traditionally used in the treatment of cough, colds, bronchitis, asthma, and colic in Middle America for antispasmodic activity. MATERIALS AND METHODS: We used a porcine bronchial bioassay to study contractile responses to carbachol and histamine in the absence or presence of the essential oil. RESULTS: The essential oil showed anti-histaminergic and anti-cholinergic activities at 100 microg/ml. CONCLUSIONS: The anti-histaminergic and anti-cholinergic activities of the essential oil of Lippia dulcis support the rational use of the plant or plant extracts to treat bronchospasm.     

Chemical constituents from Lippia sidoides and cytotoxic activity.

Eleven known compounds and a new prenylated naphthoquinone, lippsidoquinone (13), were isolated from ethanol extracts of Lippia sidoides. Their structures were established by a combination of 1D and 2D NMR, IR, and EIMS spectral data analysis. The cytotoxic properties of compounds 3--13 were evaluated against HL60, SW1573, and CEM cell lines. Only tectol (6) and lippsidoquinone (13) exhibited significant activity against human leukemia cell lines HL60 and CEM.     

alpha-Glucosidase inhibitory activity of triterpenoids from Cichorium intybus

Two new triterpenoids, 18alpha,19beta-20(30)-taraxasten-3beta,21alpha-diol (cichoridiol) (1) and 17-epi-methyl-6-hydroxyangolensate (intybusoloid) (2), were obtained from the methanolic extract of seeds of Cichorium intybus along with 11 known compounds, lupeol (3), friedelin (4), beta-sitosterol (5), stigmasterol (6), betulinic acid (7), betulin (8), betulinaldehyde (9), syringic acid (10), vanillic acid (11) 6,7-dihydroxycoumarin (12), and methyl-alpha-D-galactopyranoside (13). Compounds 1, 1a, and 11 showed a good alpha-glucosidase inhibitory activity.     

Antigiardial activity of triterpenoids from root bark of Hippocratea excelsa

Two new triterpenoids, 21 beta-hydroxyolean-12-en-3-one (1) and a seco-dinor derivative of pristimerine named dzununcanone (2), were isolated from the root bark of Hippocratea excelsa. Their structures were assigned on the basis of spectroscopic evidence, mainly 1H and 13C 1D and 2D NMR including DEPT, COSY, ROESY, HSQC, and HMBC experiments, as well as EIMS and HREIMS. The known 21alpha-hydroxy-3-oxofriedelane (3), a compound new to the species, and the known methide quinones pristimerine (4) tingenone (5), and xuxuarine Ebeta (7) were also isolated. The antiprotozoal activities were determined against Giardia intestinalis. Pristimerine and tingenone were the most active antigiardial compounds, with IC50 values of 0.11 and 0.74 microM, respectively, compared with metronidazole, the current drug of choice (IC50 1.23 microM).     

Two new triterpenoids from Azadirachta indica and their insecticidal activity

Two new triterpenoids, 22,23-dihydronimocinol (1) and desfurano-6alpha-hydroxyazadiradione (2), were isolated from a methanolic extract of the fresh leaves of Azadirachta indica (neem) along with a known meliacin, 7alpha-senecioyl-(7-deacetyl)-23-O-methylnimocinolide. The structures of 1 and 2 were elucidated through spectral and chemical studies. Compounds 1 and 2 showed mortality for fourth instar larvae of the mosquito (Anopheles stephensi), with LC(50) values of 60 and 43 ppm, respectively.     

An unprecedented neolignan skeleton from Chimarrhis turbinata

A lignan with a new skeleton named chimarrhinin (1) was isolated from an extract of the leaves of Chimarrhis turbinata, a Rubiaceae plant species. (13)C NMR spectrometric techniques including 1D and 2D experiments and HRESIMS provided unequivocal structural confirmation of this new C(6).C(3) skeleton type. The relative configuration of 1 was established by 2D (1)H-H analysis and J couplings, while its conformation was evaluated through molecular modeling using the RM1 semiempirical method, with the aid of coupling constants obtained by NMR analysis. The antioxidant activity of the new derivative 1 and two known and previously isolated phenolic derivatives (2 and 3) was investigated. An IC(50) value of 7.50 ± 0.5 μmol L(-1) was obtained for the new derivative 1, while 2 and 3 showed IC(50) values of 18.60 ± 0.4 and 18.50 ± 0.6 μmol, respectively.     

Antibacterial activity of naphthoquinones and triterpenoids from Euclea natalensis root bark

Phytochemical studies of an ethanolic extract of Euclea natalensis root bark afforded two new compounds, octahydroeuclein (1) and 20(29)-lupene-3 beta-isoferulate (2), in addition to three known compounds, shinanolone (3), lupeol, and betulin. The chemical structures of 1 and 2 were determined by spectroscopic means. Shinanolone (3) showed inhibitory activity against Gram-positive bacterial strains and a drug-sensitive strain of Mycobacterium tuberculosis at a concentration of 0.1 mg/mL.     

Antitubercular chromones and flavonoids from Pisonia aculeata

Three new chromones, pisonins A (1), B (2), and D (4), two new flavonoids, pisonivanone [(2S)-5,7,2'-trihydroxy-8-methylflavanone] (7) and pisonivanol [(2R,3R)-3,7-dihydroxy-5,6-dimethoxyflavanone] (8), one new isoflavonoid, pisonianone (5,7,2'-trihydroxy-6-methoxy-8-methylisoflavone) (9), and five compounds first isolated from nature, namely, pisonins C (3), E (5), and F (6), pisoniamide (10), and pisonolic acid (11), together with 18 known compounds have been isolated from the methanol extract of the combined stem and root of Pisonia aculeata. Among these isolates, 2, 7, 14, 16, and 19 exhibited antitubercular activities (MICs≤50.0 μg/mL) against Mycobacterium tuberculosis H37Rv in vitro.     

In vitro antiviral activity of dammar resin triterpenoids

Nine triterpenes with antiviral activity against Herpes simplex virus types I and II in vitro were isolated from dammar resin. Each compound caused a significant reduction in viral cytopathic effect when Vero cells were exposed continuously to 1-10 micrograms/ml of compound for 48 h after viral challenge. The triterpenes were identified as dammaradienol [1], dammarenediol-II [2], hydroxydammarenone-I [3], ursonic acid [5], hydroxyhopanone [11], dammarenolic acid [15], shoreic acid [16], eichlerianic acid [17], and a novel compound, hydroxyoleanonic lactone [7], on the basis of their chromatographic, spectroscopic, and physical properties.     

Bioactive triterpenoids from Salvia species

Salvia species are important medicinal and culinary plants, and they have been the subject of numerous chemical and biological studies. The bioactive triterpenoids of Salvia species, reported in the literature to date, are reviewed. About 200 triterpenoids, almost 80 of which are new, isolated, and characterized from about 100 Salvia species, are presented herein. In addition to the diverse biological activities of the pure triterpenoids, studies on biological activity of extracts of Salvia species are also described.     

Serratene-type triterpenoids from Huperzia serrata

Seven new and 15 known serratene-type triterpenoids were isolated from the whole plant of Huperzia serrata. The structures of these new triterpenoids were elucidated as 21alpha-hydroxyserrat-14-en-3beta-yl p-dihydrocoumarate (1), 21alpha-hydroxyserrat-14-en-3beta-yl dihydrocaffeate (2), 21alpha-hydroxyserrat-14-en-3beta-yl propanedioic acid monoester (3), 3alpha,21alpha-dihydroxyserrat-14-en-24-oic acid (4), 16-oxo-3alpha,21beta-dihydroxyserrat-14-en-24-al (5), 16-oxo-3alpha,21beta-dihydroxyserrat-14-en-24-oic acid (6), and 16-oxo-21beta-hydroxyserrat-14-en-3alpha-yl acetate (7), respectively, by means of spectroscopic analysis.     

Antitubercular constituents from Premna odorata Blanco

Ethnopharmacological relevance

Premna odorata Blanco (Lamiaceae) is a medicinal plant traditionally used in Albay Province, in southeastern Luzon, Philippines to treat tuberculosis. This study aimed to determine the antitubercular property of the crude extract and sub-extracts of the leaves, and to isolate the bioactive principles from the active fractions.

Materials and methods

Through extraction, solvent polarity-based fractionation and silica gel chromatography purification of the DCM sub-extract, compound mixtures from the bioactive fractions were isolated and screened for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H₃₇Rv using the colorimetric Microplate Alamar Blue assay (MABA).

Results

The crude methanolic extract and sub-extracts showed poor inhibitory activity against Mycobacterium tuberculosis H₃₇Rv (MIC≥128 µg/mL). However, increased inhibitory potency was observed for fractions eluted from the DCM sub-extract (MIC=54 to 120 µg/mL). Further purification of the most active fraction (MIC=54 µg/mL) led to the isolation of a 1-heneicosyl formate (1), 4:1 mixture of β-sitosterol (2), stigmasterol (3) and diosmetin (4), which were identified through GC–MS analysis (with dereplication) and NMR experiments. The MIC of compound 1 was 8 µg/mL.

Conclusions

The results of this study provide scientific basis for the traditional use of Premna odorata as treatment for tuberculosis.     

Cucurbitane-type triterpenoids from Momordica charantia

Five new cucurbitane-type triterpenes, (23E)-25-methoxycucurbit-23-ene-3beta,7beta-diol (1), (23E)-cucurbita-5,23,25-triene-3beta,7beta-diol (2), (23E)-25-hydroxycucurbita-5,23-diene-3,7-dione (3), (23E)-cucurbita-5,23,25-triene-3,7-dione (4), and (23E)-5beta,19-epoxycucurbita-6,23-diene-3beta,25-diol (5), together with one known triterpene, (23E)-5beta,19-epoxy-25-methoxycucurbita-6,23-dien-3beta-ol (6), have been isolated from the methanol extract of the stems of Momordica charantia. The structures of the new compounds were elucidated by spectroscopic methods.     

Antiplasmodial triterpenoids from Ekebergia capensis

From the stem bark of Ekebergia capensis, 10 new triterpenoid compounds, ekeberins A (1), B (2), C1 (3), C2 (4), C3 (5), D1 (6), D2 (7), D3 (8), D4 (9), and D5 (10), were isolated together with 17 known compounds. The structures of these new compounds were elucidated on the basis of the results of spectroscopic analysis, and the absolute configuration of compounds 6-10 were determined by partial synthesis from known compounds and using the Mosher ester method. Several of these compounds were screened in vitro against both chloroquine (CQ)-sensitive and -resistant Plasmodium falciparum isolates and were found to exhibit moderate antiplasmodial activity, with compounds 20 (7-deacetoxy-7-oxogedunin) and 27 (2-hydroxymethyl-2,3,22,23-tetrahydroxy-2,6,10,15,19,23-hexamethyl-6,10,14,18-tetracosatetraene) showing IC50 values of 6 and 7 microM, respectively. Compound 27 at a dose of 500 mg/kg showed moderate parasitemia suppression of 52.9% against P. berghei NK 65 in a mouse model.     

Cucurbitane triterpenoids from Leucopaxillus gentianeus

In addition to the known bioactive triterpene cucurbitacin B (1), two new cucurbitane triterpenoids, namely, leucopaxillones A (3) and B (4), exhibiting a new oxygenation pattern among cucurbitacins, have been isolated from the mushroom Leucopaxillus gentianeus (syn. L. amarus). Cucurbitacin B (1) imparts a bitter taste to the flesh of the fungus; however, it occurs in the fruiting bodies mainly esterified as tasteless fatty acid esters 2a-c. In vitro growth inhibitory effects of compounds 1-4 on proliferation of four different human tumor cell lines (A549, CAKI-1, HepG2, MCF-7) were evaluated by using a 1-day MTT assay. Only cucurbitacin B was highly active on all lines. Free cucurbitacin B is presumed to be formed in vivo by an enzyme-mediated scission of esters 2a-c, thus constituting a chemical weapon that protects the mushrooms against parasites and predators. Compounds 1-4 are structurally different from the other few cucurbitacins isolated from Basidiomycetes, being, instead, more similar to those occurring in plants. In particular, cucurbitacin B (1) seems to represent an interesting example of secondary metabolite convergence between distant taxa such as fungi and vascular plants, where they likely exert a similar role of protection. The structures of the compounds were established by means of spectroscopic methods and X-ray diffraction on a single crystal. The absolute configuration of leucopaxillone A has been assigned on the basis of CD chirality rules.     

Cytotoxic triterpenoids from Maytenus retusa

Seven new triterpenoids (1-7) and 36 known compounds were isolated from the root bark of Maytenus retusa. Their structures were determined by 1D and 2D spectroscopic studies. Several compounds were evaluated for their cytotoxicity against the human tumor cell lines HL-60 and MCF-7. Some of them were cytotoxic, with IC(50) values ranging between 0.2 and 4.7 μM.     

Tirucallane-type triterpenoids from Dysoxylum lenticellatum

Ten new tirucallane-type triterpenoids, represented by a rearranged skeleton dysolenticin A (1), dysolenticin B (2), a rare trinortriterpenoid dysolenticin C (3), three tirucallane triterpenoid derivatives with a hemiketal moiety dysolenticins D-F (4-6), dysolenticins G-I (7, 9, 10), and the new alkaloid dysolenticin J (12), together with seven known analogues were isolated from the twigs and leaves of Dysoxylum lenticellatum. Their structures were elucidated by extensive spectroscopic methods, and those of compounds 1, 3, 4, 6, and 10 were confirmed by single-crystal X-ray diffraction experiments. Dysolenticin J (12) showed significant vasodilative effects on intact rat aortic rings with a diastolic degree of 87.4% at 10 μg/mL.     

Cycloartane triterpenoids from Astragalus bicuspis

Three new cycloartane glycosides have been isolated from Astragalus bicuspis. They were identified as 6alpha-hydroxy-3-O-beta-xylopyranosyloxy-24,25,26,27-tetranor-9,19-cyclolanosta-16,23-lactone (1), 6alpha-hydroxy-23-methoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-beta-xyloside (2), and 23(R),24(S),25(R),26(S)-16beta/23,23/26,24/25-triepoxy-6alpha,26-dihydroxy-9,19-cyclolanosta-3-O-beta-xyloside (3), on the basis of their spectroscopic data. Two known cycloartane derivatives, 4 and 5, were also obtained from this plant. Compounds 2-5 were tested for leishmanicidal activity against Leishmania major promastigotes and for cytotoxicity against 3T3 cancer cells.     

Antimicrobial triterpenoids from Vladimiria muliensis

A new triterpenoid with a rearranged ursane skeleton, 3beta-acetoxyl-11alpha-methoxybauer-8-en-7alpha-ol ( 1), two new ursane triterpenoids, 1alpha,5alpha-dioxy-11alpha-hydroxyurs-12-en-3-one ( 2) and urs-3beta,13alpha,18beta-triol ( 3), together with three known ursane triterpenoids ( 4- 6) were isolated from the rhizome of Vladimiria muliensis. Their structures were elucidated on the basis of spectroscopic methods (IR, EIMS, HRESIMS, 1D and 2D NMR, and X-ray crystallography diffraction). Compounds 2 and 4 exhibited modest antimicrobial activity against Escherichia coli, Candida albicans, Pseudomonas aeruginosa, Enterococcus faecalis, Bacillus cereus, and Staphylococcus aureus.     

Antitubercular sesterterpenes from the Thai sponge Brachiaster sp

A new scalarane-type sesterterpene, 12-deacetoxyscalarin 19-acetate (2), and two naturally new derivatives of manoalide-type sesterterpenes, (E)- and (Z)-neomanoalide 24,25-diacetates (3 and 4), were isolated from the Thai sponge Brachiaster sp., along with five other known sesterterpenes: heteronemin (1), heteronemin acetate (5), 12-epi-19-deoxyscalarin (6), 12-deacetyl-12-epi-19-deoxyscalarin (7), and manoalide 25-acetate (8). The antitubercular and cytotoxic activities of all eight compounds were evaluated to reveal the potent activity of compounds 1, 2, 5, and 8. Among these, compound 2 showed an interesting bioactivity profile, in possessing potent antitubercular activity and being practically inactive in the cytotoxicity bioassay.