Chemical Constituents from Agave applanata and Its Antihyperglycemic, Anti-inflammatory, and Antimicrobial Activities Associated with Its Tissue Repair Capability

Agave applanata is a Mexican agave whose fresh leaves are employed to prepare an ethanol tonic used to relieve diabetes. It is also applied to skin to relieve varicose and diabetic foot ulcers, including wounds, inflammation, and infections. In this study, the chemical composition of this ethanol tonic is established and its association with antihyperglycemic, anti-inflammatory, antimicrobial, and wound healing activities is discussed. The fresh leaves of A. applanata were extracted with ethanol : H2O (85 : 15). A fraction of this extract was lyophilized, and the remainder was partitioned into CH2Cl2, n-BuOH, and water. CH2Cl2 and n-BuOH fractions were subjected to a successive open column chromatography process. The structure of the isolated compounds was established using nuclear magnetic resonance and mass spectrometry spectra. The antihyperglycemic activity was evaluated through in vivo sucrose and glucose tolerance experiments, as well as ex vivo intestinal absorption and hepatic production of glucose. Wound healing and edema inhibition were assayed in mice. The minimum inhibitory concentrations (MICs) of the hydroalcoholic extract, its fractions, and pure compounds were determined through agar microdilution against the most isolated pathogens from diabetic foot ulcers. Fatty acids, β-sitosterol, stigmasterol, hecogenin (1: ), N-oleyl-D-glucosamine, β-daucosterol, sucrose, myo-inositol, and hecogenin-3-O-α-L-rhamnopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)-β-D-glucopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-β-D-galactopyranoside (2: ) were characterized. This research provides evidence for the pharmacological importance of A. applanata in maintaining normoglycemia, showing anti-inflammatory activity and antimicrobial effects against the microorganisms frequently found in diabetic foot ulcers. This plant plays an important role in wound healing and accelerated tissue reparation.

Glaucacetalin E and galphimidin B from Galphimia glauca and their anxiolytic activity

ETHNOPHARMACOLOGICAL RELEVANCE

Galphimia glauca is a Mexican medicinal plant used to treat anxiety, fear, phobia and stress as it possesses sedative properties which produce a calming effect. Although some chemical and pharmacological studies have already been carried out on G. glauca, there are still new chemical entities from this plant whose anxiolytic activity should be established.

AIM OF THE STUDY

To validate the use of G. glauca growing in Cuernavaca, Morelos, as an anti-stress agent, through the purification and structural identification of its extracts' chemical constituents; the analysis of the biogenetic relationship of its chemical compounds, and its biological evaluation to demonstrate its traditional use as anxiolytic agents.

MATERIALS AND METHODS

The structures of all isolated compounds were established based on their spectroscopic and spectrometric data. The structure of compound 2 was corroborated through X-Ray. The anxiolytic and sedative-like activities were assessed by the open-field, hole-board and exploration cylinder test.

RESULTS

The nor-triterpenes glaucacetalin E (1) and galphimidin B (2) were isolated for the first time along with seven other known compounds, one of them galphimidin (3), from the CHCl₃ fraction of the aerial parts of Galphimia glauca. The biogenesis of the natural nor-triterpenes isolated from Galphimia glauca is delineated for the first time starting from the taraxasteryl cation. Oral administration of CHCl₃ fraction and 1-3 compounds produced significant attenuation in the anxiety-response in cylinder activity, decrease in the ambulatory activity and in head dipping when compared to the vehicle. However, only the extract enhanced the pentobarbital-induced hypnosis. Diazepam was used as a positive control.

CONCLUSION

Our results suggest that G. glauca growing in Cuernavaca, Morelos, exerts anxiolytic-like activity due to the presence of the nor-triterpenes 1-3. These results reinforce the potential use of this species in the treatment of anxiety.

UPLC-QTOF-MS analysis of cytotoxic and antibacterial extracts of Hechtia glomerata Zucc

Hechtia glomerata, a Mexican medicinal plant employed against bacterial infections and as food, is taxonomically related to the genus Tillandsia which has anticancer activity. Organic and aqueous extracts of H. glomerata leaves were prepared and tested for cytotoxic and antibacterial activity. UPLC-QTOF-MS analysis determined the chemical composition of active extracts to find cytotoxic and antibacterial compounds. Hexane extract was cytotoxic against HepG2, Hep3B and MCF7 (IC₅₀: 24-28 µg/mL), whereas CHCl₃/MeOH extract against PC3 and MCF7 (IC₅₀: 25 and 32 µg/mL). CHCl₃/MeOH extract showed antibacterial activity against Staphylococcus aureus and Enterococcus faecium (MIC: 125 and 62.5 µg/mL). Hexane extract cytotoxic compounds were β-sitosterol, stigmasterol, phytol and ursolic acid. CHCl₃/MeOH extract antibacterial and/or cytotoxic compounds were daucosterol, oleanolic acid, resveratrol, quercetin, kaempferol, apigenin, cyanidin, p-coumaric acid and caffeic acid. This plant could be useful against bacterial infections and cancer. However, in vivo studies are needed to determine its toxicity and therapeutic efficacy.

1 H and 13 C NMR data, occurrence, biosynthesis, and biological activity of Piper amides

Alkamides are the major and characteristic chemical compounds of the plants belonging to the Piper genus. These compounds are responsible for the flavor of pepper spices and for its broad use in cuisine across many regions of the world. Humans are in contact every day with these substances, which additionally show a broad variety of pharmacological activities, making them an important research target. A large amount of NMR data for these natural products is dispersed throughout literature. Its organization will help those research groups interested in their identification and structural elucidation. This review summarizes the ¹ H and ¹³ C NMR data of 268 Piper amides in a systematic and orderly way, with a discussion on their biological activities, biosynthetic aspects, and NMR analysis of typical and relevant aspects of this information.

Phytotoxic and nematicide evaluation of Croton ehrenbergii (Euphorbiaceae)

BACKGROUND

Within its natural habitat, Croton ehrenbergii exhibits an innate defense mechanism that is not seen in other plants; it grows unharmed amidst predators and nature, while other species perish. In light of its capacity for defense, C. ehrenbergii was evaluated to better understand the scope of its phytotoxic and nematicide properties. To assess this, fractions obtained by bipartition of a hydro-alcoholic extract, and l-quebrachitol, the main constituent of C. ehrenbergii, were evaluated on Lactuca sativa (dicotyledon) and Lolium perenne (monocotyledon) seeds. Additionally, bipartition fractions and l-quebrachitol were evaluated on a population of Meloidogyne incognita for their nematicide activity.

RESULTS

From this phytochemical research, l-quebrachitol (1), phenylalanine (2), trans-4-hydroxy-N-methylproline (3) and the flavonoids: kaempferol (4), tiliroside (5), nicotiflorine (6) and rutin (7) were identified by spectroscopic analysis. Both methanol and hexane fractions from aerial parts of the plant inhibited the germination and elongation of roots and stems in L. sativa, but not in Lolium perenne, showing that these fractions mostly inhibit the dicotyledon species used in this research. l-Quebrachitol showed slightly higher seed germination inhibition for Lolium perenne in comparison with L. sativa. Three of the fractions evaluated showed nematicide activity against Meloidogyne incognita larvae (J2) at the 48 h benchmark, compared with carbofuran. l-Quebrachitol shows higher mortality after 48 h exposure at a lower concentration than carbofuran.

CONCLUSION

A variety of compounds were isolated from this research, some were common within the Croton genus (4-7), whereas others were not (1-3). This is the first phytochemical, phytotoxic and nematicide report on C. ehrenbergii. Methanol and hexane fractions from the aerial parts of C. ehrenbergii and l-quebrachitol could be used as alternative natural herbicides, predominantly against dicotyledon weed seeds. All fractions had a good mortality percentage against J2 Meloidogyne incognita larvae. © 2019 Society of Chemical Industry.

Phytotoxic Potential of Zanthoxylum affine and Its Major Compound Linarin as a Possible Natural Herbicide

Four compounds, the flavone linarin (1), the triterpene lupenone (2), the tocopherol (vitamin E, 3), and the new natural alkaloid 1,2,3,4-tetrahydro-1,1-dimethyl-6,7-isoquinolindiol (affineine, 4), were the major natural products isolated from Zanthoxylum affine (syn. Zanthoxylum fagara, Rutaceae). Compound 1 is highly abundant in this plant and was isolated as a white precipitate obtained from the acetone and methanol extracts. The structure of these four compounds was established by 1D and 2D NMR spectroscopy including ¹H, ¹³C, DEPT, COSY, HSQC, and HMBC experiments. The hexane, acetone, and methanol extracts, as well as 1, were evaluated for their potential phytotoxic effects in pre- and post-emergent assays, as well as to identify their mechanisms of action. As pre-emergent phytotoxic agents, the hexane, acetone, and methanol extracts inhibited germination and residual growth (root and stem elongation) of Lactuca sativa (lettuce) and Lolium perenne (perennial ryegrass). As post-emergent agents, they inhibited dry biomass. Compound 1 acts as a pre-emergent herbicide, by inhibiting germination, seed respiration, residual seedling growth and, notably, root hair development. Furthermore, 1 inhibited the synthesis of ATP and the electron transport chain of isolated spinach chloroplasts; in this way, it behaves as a Hill reaction inhibitor. The site of inhibition was located at the donor site of PSII from the oxygen evolving complex to Q_A, thus acting as a multisite compound. These results suggest that compound 1 can be used as a lead for a potential green herbicide with different targets.

Sulfur-Containing Aristoloxazines and Other Constituents of the Roots of Aristolochia orbicularis

Six new compounds, aristoloxazine A (1), aristoloxazine B (2), 7-methoxytaliscanine (3), humul-7-en-1,4,11-triol (4), 8-hydroxy-β-logipinene (5), and 1β-hydroxy-4(14)-eudesmene (6), corresponding to two sulfur-containing aristoloxazines (1 and 2), an aristolactam (3), and three sesquiterpenes (4-6) were isolated, along with 26 known compounds, from the roots of Aristolochia orbicularis. The structures of the new compounds were established based on their spectroscopic and spectrometric data and in the case of aristoloxazine A (1) by single-crystal X-ray crystallography. This is the first report of sulfur-containing aristoloxazines from a natural source. Furthermore, aristoloxazine A (1) was found to possess potent in vitro antimicrobial activity against all resistant Staphylococcus aureus and several fungal strains in which it was evaluated.

Antinociceptive effect of natural and synthetic alkamides involves TRPV1 receptors

Objective

To establish the role of TRPV1 receptor in the antinociceptive effect of natural alkamides (i.e. affinin, longipinamide A, longipenamide A and longipenamide B) isolated from Heliopsis longipes (A. Gray) S.F. Blake and some related synthetic alkamides (i.e. N-isobutyl-feruloylamide and N-isobutyl-dihydroferuloylamide).

Methods

The orofacial formalin test was used to assess the antinociceptive activity of natural (1–30 μg, orofacial region) and synthetic alkamides (0.1–100 μg, orofacial region). The alkamide capsaicin was used as positive control, while capsazepine was used to evaluate the possible participation of TRPV1 receptor in alkamide-induced antinociception.

Key findings

Natural (1–30 μg) and synthetic (0.1–100 μg) alkamides administered to the orofacial region produced antinociception in mice. The antinociceptive effect induced by affinin, N-isobutyl-feruloylamide and N-isobutyl-dihydroferuloylamide was antagonized by capsazepine but not by vehicle.

Conclusions

These results suggest that alkamide affinin, longipinamide A, longipenamide A and longipenamide B isolated from Heliopsis longipes as well as the synthesized analogue compounds N-isobutyl-feruloylamide and N-isobutyl-dihydroferuloylamide produce their effects by activating TRPV1 receptor and they may have potential for the development of new analgesic drugs for the treatment of orofacial pain.

Hepta-, hexa-, penta-, tetra-, and trisaccharide resin glycosides from three species of Ipomoea and their antiproliferative activity on two glioma cell lines

Six new partially acylated resin glycosides were isolated from convolvulin of Ipomoea purga, Ipomoea stans, and Ipomoea murucoides (Convolvulaceae). The structures of compounds 1-6 were elucidated by a combination of NMR spectroscopy and mass spectrometry. The structure of jalapinoside B (1) consists of a hexasaccharide core bonded to an 11-hydroxytetradecanoic (convolvulinic) acid forming a macrolactone acylated by a 2-methylbutanoyl, a 3-hydroxy-2-methylbutanoyl, and a quamoclinic acid B units. Purginoic acid A (2) contains a hexasaccharide core bonded to a convolvulinic acid acylated by a 3-hydroxy-2-methylbutanoyl unit. Stansin A (4) is an ester-type heterodimer, and consists of two stansoic acid A (3) units, acylated by 2-methylbutanoic and 3-hydroxy-2-methylbutanoic acids. The site of lactonization was located at C-3 of Rhamnose, and the position for the ester linkage of the monomeric unit B on the macrolactone unit A was established as C-4 of the terminal rhamnose. Compounds 5 and 6 are glycosidic acids. Murucinic acid II (5) is composed of a pentasaccharide core bonded to an 11-hydroxyhexadecanoic (jalapinolic) acid, acylated by an acetyl unit. Stansinic acid I (6) is a tetrasaccharide core bonded to a jalapinolic acid, acylated by 2-methylbutanoyl and 3-hydroxy-2-methylbutanoyl units. Preliminary testing showed the cytotoxicity of compounds 1-6 toward OVCAR and UISO-SQC-1 cancer cell lines. In addition, compound 1 showed an antiproliferative activity on glioma C6 and RG2 tumor cell lines. Copyright © 2016 John Wiley & Sons, Ltd.

Vasorelaxant mode of action of dichloromethane-soluble extract from Agastache mexicana and its main bioactive compounds

CONTEXT

Agastache mexicana (Kunth) Lint & Epling (Lamiaceae) is a plant used in Mexican traditional medicine for the treatment of hypertension, anxiety and so on.

OBJECTIVE

To determine the vasorelaxant effect and functional mode of action of dichloromethane-soluble extract from A. mexicana (DEAm) and isolate the constituents responsible for the pharmacological activity.

MATERIALS AND METHODS

Extracts were prepared from the aerial parts of A. mexicana (225.6 g) by successive maceration with hexane, dichloromethane and methanol (three times for 72 h at room temperature), respectively. DEAm (0.01-1000 μg/mL), fractions (at 174.27 μg/mL), acacetin and ursolic acid (UA) (0.5-500 μM) were evaluated to determine their vasorelaxant effect on ex vivo rat aorta ring model. In vivo UA antihypertensive action was determined on spontaneously hypertensive rats.

RESULTS AND DISCUSSION

DEAm induced a significant vasorelaxant effect in concentration-dependent and endothelium-independent manners (EC₅₀=174.276 ± 5.98 μg/mL) by a calcium channel blockade and potassium channel opening. Bio-guided fractionation allowed to isolate acacetin (112 mg), UA (2.830 g), acacetin/oleanolic acid (OA) (M1) (155 mg) and acacetin/OA/UA (M2) (1.382 g) mixtures, which also showed significant vasodilation. UA significantly diminished diastolic (80 mmHg) and systolic blood pressure (120 mmHg), but heart rate was not modified.

CONCLUSION

DEAm produced significant vasorelaxant action by myogenic control cation. The presence of acacetin, OA and UA into the extract was substantial for the relaxant activity of DEAm. In vivo antihypertensive action of UA corroborates the use of A. mexicana as an antihypertensive agent on Mexican folk medicine.

(1) H and (13) C NMR data on natural and synthetic capsaicinoids

Capsaicinoids are the compounds responsible for the pungency of chili peppers. These substances have attracted the attention of many research groups in recent decades because of their antinociceptive, analgesic, anti-inflammatory, and anti-obesity properties, among others. There are nearly 160 capsaicinoids reported in the literature. Approximately 25 of them are natural products, while the rest are synthetic or semi-synthetic products. A large amount of NMR data for the capsaicinoids is dispersed throughout literature. Therefore, there is a need to organize all this NMR data in a systematic and orderly way. This review summarizes the (1) H and (13) C NMR data on 159 natural and synthetic capsaicinoids, with a brief discussion of some typical and relevant aspects of these NMR data. Copyright © 2015 John Wiley & Sons, Ltd.

Is Allelopathic Activity of Ipomoea murucoides Induced by Xylophage Damage?

Herbivory activates the synthesis of allelochemicals that can mediate plant-plant interactions. There is an inverse relationship between the activity of xylophages and the abundance of epiphytes on Ipomoea murucoides. Xylophagy may modify the branch chemical constitution, which also affects the liberation of allelochemicals with defense and allelopathic properties. We evaluated the bark chemical content and the effect of extracts from branches subjected to treatments of exclusion, mechanical damage and the presence/absence of epiphytes, on the seed germination of the epiphyte Tillandsia recurvata. Principal component analysis showed that branches without any treatment separate from branches subjected to treatments; damaged and excluded branches had similar chemical content but we found no evidence to relate intentional damage with allelopathy; however 1-hexadecanol, a defense volatile compound correlated positively with principal component (PC) 1. The chemical constitution of branches subject to exclusion plus damage or plus epiphytes was similar among them. PC2 indicated that palmitic acid (allelopathic compound) and squalene, a triterpene that attracts herbivore enemies, correlated positively with the inhibition of seed germination of T. recurvata. Inhibition of seed germination of T. recurvata was mainly correlated with the increment of palmitic acid and this compound reached higher concentrations in excluded branches treatments. Then, it is likely that the allelopathic response of I. murucoides would increase to the damage (shade, load) that may be caused by a high load of epiphytes than to damage caused by the xylophages.

In vitro COX-1 and COX-2 enzyme inhibitory activities of iridoids from Penstemon barbatus, Castilleja tenuiflora, Cresentia alata and Vitex mollis

A group of sixteen iridoids isolated from plants used as anti-inflammatory remedies in Mexican folk medicine were evaluated for their potential to inhibit cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes. From these assays, loganic acid (10) was identified as the most promising compound with both COX-1 (36.0 ± 0.6%) and COX-2 (80.8 ± 4.0%) inhibition at 10 μM. Compound 10 shows a better inhibition against the COX-2 enzyme. Other iridoids tested in the present study showed weak or no inhibition against these enzymes. Furthermore, herein are presented key interactions of iridoid 10 with COX-1 and COX-2 enzymes through molecular docking studies. These studies suggest that 10 exhibits anti-inflammatory activity due to COX inhibition.

Karwinaphthopyranones from the fruits of Karwinskia parvifolia and their cytotoxic activities

The new 2-acetyl-8-methoxynaphthol (1) and five new "dimeric" napthopyranones, karwinaphthopyranones A1 and A2 (2 and 3) and karwinaphthopyranones B1-B3 (4-6), possessing a methoxy group at C-5', were isolated together with four other known compounds from the dried fruits of Karwinskia parvifolia. The structures of compounds 2-6 were determined by spectroscopic data interpretation. Cell culture assays showed that some of these compounds possess antiproliferative activities in representative human cancer cell lines, with half-maximal growth inhibitory concentrations in the micromolar range.

Semisynthesis, ex vivo evaluation, and SAR studies of coumarin derivatives as potential antiasthmatic drugs

Asthma is a chronic inflammatory disorder that causes contraction in the smooth muscle of the airway and blocking of airflow. Reversal the contractile process is a strategy for the search of new drugs that could be used for the treatment of asthma. This work reports the semisynthesis, ex vivo relaxing evaluation and SAR studies of a series of 18 coumarins. The results pointed that the ether derivatives 1-3, 7-9 and 13-15 showed the best activity (Emax = 100%), where compound 2 (42 μM) was the most potent, being 4-times more active than theophylline (positive control). The ether homologation (methyl, ethyl and propyl) in position 7 or positions 6 and 7 of coumarins lead to relaxing effect, meanwhile formation of esters generated less active compounds than ethers. The SAR analysis showed that it is necessary the presence of two small ether groups and the methyl group at position 4 (site 3) encourage biological activity through soft hydrophobic changes in the molecule, without drastically affecting the cLogP.

Antimutagenic properties of affinin isolated from Heliopsis longipes extract

CONTEXT

Heliopsis longipes (A. Gray) Blake (Asteraceae), commonly known in Mexico as "chilcuage" or "chilcuan", is widely used as an analgesic and anesthetic agent. Affinin, the major metabolite of this plant, and the ethanol extract of the plant have shown antinociceptive properties in mice. H. longipes plant produces a complex mixture of antioxidant chlorophylls and polyamines as well as a number of possible antimutagens.

OBJECTIVE

The current study evaluated the potential utilization of the natural product affinin isolated from H. longipes ethanol extract as an antimutagenic and possibly anticarcinogenic agent.

MATERIALS AND METHODS

The Ames assay was used to assess the mutagenic properties of affinin (12.5, 25 and 50 µg/plate) that was added to several mutagens with or without S9 metabolic activation in Salmonella typhimurium (TA98, TA100 and TA102 strains).

RESULTS

Heliopsis longipes extract and affinin were not toxic as a reduction in the number of His⁺ revertant bacteria colonies. Affinin (25 and 50 µg/plate) significantly reduced the frameshift mutations that were generated by 2-aminoanthracene (2AA) (40%) and reduced the oxidative DNA damage generated by norfloxacin (NOR) (37-50%). Affinin possessed antioxidant properties that were able to reduce 2AA- and NOR-induced mutations in S. typhimurium TA98 and TA102, respectively.

DISCUSSION AND CONCLUSION

Affinin, the principal metabolite of H. longipes, is not mutagenic and possesses antimutagenic activity. These plants are currently used to treat some pain symptoms in Mexico; and antimutagen activity determined could be important to treat some pain symptoms related to antiradical activity.

Cycloartanes from Krameria pauciflora and their in vitro PLA₂, COX-1, and COX-2 enzyme inhibitory activities

Krameria pauciflora is a species belonging to the Krameriaceae family. It has been used to treat inflammatory disorders in folkloric Mexican medicine; however, chemistry and pharmacological studies have not been carried out on this species. In this work, from the dichloromethane root extract of K. pauciflora, five cycloartane-type triterpenoids were isolated: cyclomargenyl-3-O-β-caffeoyl ester (1), cyclomargenyl-3-O-β-feruloyl ester (2), cyclomargenyl-3-O-β-coumaroyl ester (3), cyclomargenol (4, polysthicol), and cyclomargenone (5). Additionally, the lignane 6'-methoxyrataniaphenol was isolated. To the best of our knowledge, compounds 1-3 are new natural products, whereas compounds 4 and 5 are isolated for the first time in the Krameria genus and the Krameriaceae family. The structures of all of these compounds were established by 1D and 2D NMR spectroscopy including ¹H, ¹³C, DEPT, COSY, HSQC, and HMBC experiments, as well as by EI mass spectrometry. There is an incomplete previous report about the spectroscopic data of compounds 4 and 5. However, in this work, a complete and unambiguous assignation has been realized. Due to the traditional use of this plant and other species from this genus, such as K. lappacea, cycloartanes isolated herein were evaluated by their inhibition of phospholipase A₂, cyclooxygenase-1, and cyclooxygenase-2 enzymes. Cyclomargenyl-3-O-β-caffeoyl ester (1) showed inhibition of phospholipase A₂, cyclooxygenase-1, and cyclooxygenase-2 target enzymes for nonsteroidal anti-inflammatory drugs. Both cyclooxygenases were inhibited by cyclomargenol (4); however, cyclomargenyl-3-O-β-feruloyl ester (2) showed inhibition only on cyclooxygenase-1.

Linear and cyclic dipeptides with antimalarial activity

Several natural and synthetic polypeptides possess important antimalarial activity. Shorter peptides with potent antimalarial activity have also been described, among them linear di-, tri-, tetra- and pentapeptides and their cyclic analogs. In an attempt to find dipeptides with antimalarial activities we show that linear and cyclic dipeptides, the latter known as diketopiperazines, still retain the fundamental core to preserve antimalarial activity. Thirteen linear dipeptides and ten diketopiperazines were investigated. Eight linear dipeptides showed IC(50) values between 2.78 and 7.07 μM, while eight diketopiperazines were also active with IC(50) values between 2.26 and 4.26 μM on Plasmodium berghei schizont cultures.

Chemical constituents of the hemiparasitic plant Phoradendron brachystachyum DC Nutt (Viscaceae)

Phoradendron brachystachyum is a hemiparasitic plant widely distributed in México that belongs to the Viscaceae family. It has been commonly used in folk medicine as a substitute for the European mistletoe. In this chemical study, morolic acid was isolated as the major component (47.54% of the total composition of acetone extract) of this plant. In addition, 19 known compounds were identified: β-sitosteryl and stigmasteryl linoleates, β-sitosterol, stigmasterol, triacontanol, squalene, α- and β-amyrin, lupeol, lupenone, betulin aldehyde, betulon aldehyde, oleanolic aldehyde, betulinic acid, betulonic acid, moronic acid, morolic acid, oleanolic acid, flavonoids acacetin and acacetin 7-methyl ether. There have been no previous reports in the literature on the chemical composition of this potential natural source of hypoglycaemic and antihypertensive compounds.

Phytochemical study and anti-inflammatory, antidiabetic and free radical scavenger evaluations of Krameria pauciflora methanol extract

The plant Krameria pauciflora MOC et. Sessé ex DC. is used as an anti-inflammatory and antidiabetic in traditional medicine. The aim of this study was to evaluate the in vivo anti-inflammatory and antidiabetic effects of a methanol extract from the roots of K. pauciflora. Dichloromethane and ethyl acetate extracts obtained by partitioning the methanol extract were also evaluated. Complete methanol and dichloromethane extracts showed anti-inflammatory effects at 3 mg/kg. An anti-inflammatory effect similar to indomethacin (10 mg/kg) was observed when the methanol and dichloromethane extracts, which contain a cycloartane-type triterpene and an sterol, were administered orally at several doses (3, 10, 30 and 100 mg/kg), whereas no anti-inflammatory effect was observed at any dose for the ethyl acetate extract, which contains catechin-type flavonoids. The antidiabetic effect of each extract was also determined. An antihyperglycaemic effect was observed in diabetic rats, but no effect in normoglycaemic animals was observed when the methanol extract was administrated at 30 mg/kg. All of the extracts exhibited radical scavenger activity. Additionally, constituents from all of the extracts were identified by NMR. This article supports the use of K. pauciflora as an anti-inflammatory because it exhibits a similar effect to indomethacin. However, its antidiabetic effect is not completely clear, although it could be useful for preventing diabetic complications.

Sedative, vasorelaxant, and cytotoxic effects of convolvulin from Ipomoea tyrianthina

AIM OF THE STUDY

Ipomoea tyrianthina has been used in Mexican traditional medicine as a mild purgative, for the treatment of nervous disorders, and against tumors. In this study, the effect of convolvulin (an ether-insoluble resin glycoside) from the root of Ipomoea tyrianthina on: Central Nervous System; as spasmolytic and vasodilator; cytotoxic against cancer cell lines is evaluated.

MATERIALS AND METHODS

Convolvulin isolated from the root of Ipomoea tyrianthina (IT-EM) was tested on pentylentetrazole induced seizures, pentobarbital-induced hypnosis, release of GABA and glutamic acid, isolated rat aorta and ileum rings, and against Caco-2 and KB cell lines.

RESULTS

IT-EM increased the hypnotic effect induced by pentobarbital and the release of GABA in brain cortex of mice, but did not protect mice against pentylenetetrazole-induced convulsions. IT-EM produced a significant vasodilator effect in concentration- and endothelium-dependent manners on isolated rat aorta, but did not inhibit significantly contractions on rat ileum, colon, and jejune rings. IT-EM showed cytotoxic activity against nasopharyngeal carcinoma KB cell line.

CONCLUSIONS

Convolvulin (IT-EM) from Ipomoea tyrianthina has sedative effect, vasorelaxant effect in concentration- and endothelium-dependent manners, and cytotoxic activity against nasopharyngeal carcinoma KB cell line.

Antinociceptive effect of Heliopsis longipes extract and affinin in mice

Heliopsis longipes is used as analgesic in Mexican traditional medicine. The present study assesses the possible antinociceptive effect of Heliopsis longipes and describes the pharmacological mechanism of action of the antinociceptive effect of affinin, identified as the one active principle in Heliopsis longipes acetone extract. Intraperitoneal administration of H. longipes extract and affinin produced a dose-dependent antinociceptive effect when assessed in mice submitted to acetic acid and capsaicin tests. Affinin-induced antinociception (30 mg/kg, I. P.) was blocked by naltrexone (1 mg/kg, S. C.), P-chlorophenylalanine (80 mg/kg, I. P.) and flumazenil (5 mg/kg, S. C.) suggesting that its pharmacological effect could be due to the activation of opiodergic, serotoninergic and GABAergic systems. In addition, the antinociceptive effect of affinin was attenuated by pretreatment with 1 H-[1,2,4]oxadiazolo[1,2- A]quinoxalin-1-one (1 mg/kg, S. C.) and glibenclamide (10 mg/kg, S. C.) suggesting that the nitric oxide-K (+) channels pathway could be involved in its mechanism of action. These results suggest that affinin itself or its derivatives may have potential antinociceptive effects.

Active compounds against tinea pedis dermatophytes from Ageratina pichinchensis var. bustamenta

Secondary metabolites 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-2,3-dihydrobenzofurane (1), 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-6-methoxy-2,3-dihydrobenzofurane (2), espeletone (3), encecalinol (4), O-methylencecalinol (5), encecalin (6), sonorol (7), taraxerol (8), (+)-beta-eudesmol (9), and a mixture of beta-sitosterol and stigmasterol, were isolated from the aerial parts of Ageratina pichinchensis var. bustamenta. The antimicrobial activity of compounds 6, 8 and 9, together with derivatives 9a and 9b against the most important dermatophytes responsible for tinea pedis infection, Trichophyton rubrum and T. mentagrophytes, and against Candida albicans and Aspergillus niger were determined, showing that the three natural products were active against both Trichophyton species. Ageratina pichinchensis var. bustamenta is used in folk medicine to treat skin infections and wounds, and this study confirms that the n-hexane extract contains metabolites which are responsible for these utilities.

Antimalarial activity of ultra-short peptides

Ultra-short peptides 1-9 were designed and synthesized with phenylalanine, ornithine and proline amino acid residues and their effect on antimalarial activity was analyzed. On the basis of the IC₅₀ data for these compounds, the effects of nature, polarity, and amino acid sequence on Plasmodium berghei schizont cultures were analyzed too. Tetrapeptides Phe-Orn-Phe-Orn (4) and Lys-Phe-Phe-Orn (5) showed a very important activity with IC₅₀ values of 3.31 and 2.57 μM, respectively. These two tetrapeptides are candidates for subsequent in vivo assays and SARS investigations.

Analgesic activity of affinin, an alkamide from Heliopsis longipes (Compositae)

Heliopsis longipes (Compositae) is a Mexican plant used as analgesic in pain toothache. A solution of 10mug/ml of dichloromethane extract from this plant showed analgesic activity determined by means of GABA release in mice brain slices. Through a bioassay-directed separation, fractions G-1, G-2, G-4 and G-6 at the same concentration were active. Affinin was the unique and common active compound, and evoke the GABA release 0.5min after administration at 1x10(-4)M concentration. Inactive compound were undeca-2E-en-8,10-dyinoic acid isobutylamide, hinokinin, 2'-hydroxyhinokinin, 3beta-sn-glyceroyl-(1''-palmitoxy)urs-12-ene, 13(18)-ursen-3beta-ol, 13(18)-ursen-3beta-acetate, beta-sitosterol and stigmasterol. The analgesic activity of Heliopsis longipes could be associated to affinin.

Iridoids from Crescentia alata

Four new 11-nor-iridoids, 6beta,7beta,8alpha,10-tetrahydroxy-cis-2-oxabicyclo[4.3.0]nonan-3-one (1), 6beta,7beta,8alpha,10-tetra-p-hydroxybenzoyl-cis-2-oxabicyclo[4.3.0]nonan-3-one (2), 1beta,6beta,7alpha,8alpha,10-pentahydroxy-cis-2-oxabicyclo[4.3.0]nonane (3), and 6beta-hydroxy-2-oxabicyclo[4.3.0]Delta8-9-nonen-1-one (4), were isolated from the pulp of the fruits of Crescentia alata. Although a limited number of Crescentia species have been studied chemically, iridoids lacking C-11 have been isolated from the fruits of these species, and the isolation of compounds 1-4 from C. alata is in accordance with the constituents of the species previously analyzed. The structures of these compounds were established on the basis of IR, UV, 1H and 13C NMR, DEPT, COSY, HSQC, HMBC, MS, and X-ray data.

1H and 13C assignments of cyclo[N-(Lys-Phe)-Orn-Val], a semicyclic imide tetrapeptide from Burkholderia cepacia

The rhizobacteria Burkholderia cepacia biosynthesized the new tetrapeptide Cyclo[N-(Lys-Phe)-Orn-Val] (1), a 2,5-diketopiperazine, and the known siderophore azurechelin (salicylic acid). The structure of 1 was established by means of IR, UV, 1H and 13C NMR, double dimension experiments and MS.

Nitrogen-containing phorbol esters from Croton ciliatoglandulifer and their effects on cyclooxygenases-1 and -2

Four new phorbol derivatives, 12-O-[(2R)-N,N-dimethyl-3-methylbutanoyl]-4-deoxyphorbol 13-acetate (1), 12-O-[(2S)-N,N-dimethyl-3-methylbutanoyl]-4-deoxyphorbol 13-acetate (2), 12-O-[3-methyl-2-butenoyl]-4-deoxyphorbol 13-acetate (3), and 12-O-[(2R)-N,N-dimethyl-3-methylbutanoyl]phorbol 13-acetate (4), along with six known compounds, were isolated from the aerial parts of Croton ciliatoglandulifer. An anti-inflammatory activity of a hexane extract of this plant was demonstrated against ear edema in mice produced by 12-O-tetradecanoylphorbol 13-acetate, and compounds 1, 4, and 3beta-O-acetyloleanolic acid (5) were active when evaluated against cyclooxygenases-1 and -2.

Myo-inositol-derived glycolipids with anti-inflammatory activity from Solanum lanceolatum

Lanceolitols A1-A7 (1-7) and B1-B7 (9-15), two series of new myo-inositol-derived glycolipid analogues, in which a sugar moiety is replaced by a fatty acid esterified myo-inositol moiety, were isolated from the leaves of Solanum lanceolatum. Their structures were elucidated on the basis of spectroscopic analysis (1H NMR, 13C NMR, 1H-1H COSY, HMQC, HMBC, and HRFABMS), as well as chemical analysis. All the compounds showed in vivo anti-inflammatory activity against ear edema in mice produced by 12-O-tetradecanoylphorbol-13-acetate (TPA). In vitro enzyme inhibition studies showed that the mixture of lanceolitols A1-A7 inhibited by 58.56% phospholipase A2 from bee venom, while the mixture of lanceolitols B1-B7 was cyclooxygenase-2 (COX-2) inhibitors (IC50 = 237 microM).

1H and 13C assignments of three new drimenes from Iresine diffusa Humb. & Bonpl. ex Willd

The structure elucidation and (1)H and (13)C assignments of iresin (1) and three new drimenes, 3beta,14-dihydroxy-Delta(7, 8)-drimen-11,12-acetonide (2), 3beta,7beta,14-trihidroxy-Delta(8, 9)-drimen-11,12-olide (3) and 3beta,7alpha,14-trihydroxy-Delta(8, 9)-drimen-11,12-olide (4), isolated from the aerial parts of the medicinal plant Iresine diffusa Humb. & Bonpl. ex Willd. are reported.

1H and 13C assignments of two new triterpenes from Cladocolea grahami

The structure elucidation and 1H and 13C assignments of the new triterpenes 3beta-palmitoxy-7beta-hydroxyolean-12-ene (1) and its hydrolysis product 3beta,7beta-dihydroxyolean-12-ene (2) and 3beta-sn-glyceroyl-(1''-palmitoxy)urs-12-ene (3), isolated from the aerial parts of Cladocolea grahami (Loranthaceae), are reported.

Three new sesquiterpenes from Croton arboreous

Three new sesquiterpenes, 5alpha,7alpha,10betaH-3-patchoulen-2-one (1), 5alpha,7alpha10betaH-4(14)-patchoulen-2alpha-ol (2), and 9alpha,10beta-dihydroxy-2beta,4beta-peroxy-1alpha,5beta,7alphaH-guaiane (3), were isolated from the aerial parts of Croton arboreous along with 14 known compounds. The structures of these compounds were determined on the bases of their spectroscopic data (IR, UV, OR, 1D and 2D NMR, and MS). The anti-inflammatory activity against ear edema in mice produced by 12-O-tetradecanoylphorbol-13-acetate (TPA) was evaluated for all the pure compounds and showed that compounds 4-7 are active.

Geranyl N-dimethylallylanthranilate, a new compound from Esenbeckia yaaxhokob

Through a bioactivity-guided fractionation from the acetone extract of the leaves from Esenbeckia yaaxhokob geranyl N-dimethylallylanthranilate ( 1), the first natural N- and O-prenylated anthranilate, was isolated in addition of the known natural products caryophyllene beta-oxide, caryolane-5beta,9beta-diol, spathulenol ( 2), friedeline, friedelanol, decaprenol, flindersiamine ( 3) and beta-sitosterol. The antimicrobial activities of the extract, fractions and pure compounds were evaluated against two Gram (+) and four Gram (-) bacteria. Compounds 1 and 2 exhibited moderated antimicrobial activity against Staphyloccocus aureus, while 3 was active against S. aureus and Streptococcus faecalis.

Two new benzofuranes from Eupatorium aschenbornianum and their antimicrobial activity

Through a bioassay-guided fractionation, from the aerial parts of the medicinal plant Eupatorium aschenbornianum were isolated two new benzofurane compounds, 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-2,3-dihydrobenzofurane ( 1) and 5-acetyl-3beta-angeloyloxy-2beta-(1-hydroxyisopropyl)-6-methoxy-2,3-dihydrobenzofurane ( 2) in addition to 4-hydroxy-3,5-diprenylacetophenone, espeletone ( 3), encecalinol ( 4), beta-sitosterol and stigmasterol. The antimicrobial evaluation of these natural products showed that 1 [MIC = 200 microg/mL against T. mentagrophytes and 100 microg/mL against T. rubrum], 2 [MIC = 50 microg/mL towards both] and 3 [MIC = 100 microg/mL against both] were active against dermatophytes, while 4 was active against all of microorganisms assayed [MIC = 12.5 microg/mL ( T. mentagrophytes), 12.5 microg/mL ( T. rubrum), 100 microg/mL ( C. albicans) and 200 microg/mL ( A. niger)].

Antifungal activities of nine traditional Mexican medicinal plants

Eighteen plant extracts from nine traditional Mexican medicinal plants were tested for antifungal activity against two dermatophyte fungal species (Trichophyton mentagrophytes and Trichophyton rubrum), one non-dermatophyte (Aspergillus niger), and one yeast (Candida albicans). The strongest effect was manifested by the hexane extracts from Eupatorium aschenbornianum and Sedum oxypetalum, as well as the methanol extracts from Lysiloma acapulcensis and Annona cherimolia.

Sterols, triterpenes and biflavonoids of Viburnum jucundum and cytotoxic activity of ursolic acid

The triterpenes ursolic acid (1), 27-p-Z-coumaroyloxyursolic acid (2), 27-p-E-coumaroyloxyursolic acid, alpha-amyrine-3-palmitate and lupeol-3-palmitate were isolated through a bioactivity-guided fractionation from the acetonic extract of the aerial parts of Viburnum jucundum Morton in addition to amentoflavone, an epimeric mixture at C-2 of 2,3-dihydroamentoflavone, beta-sitosterol and beta-sitosteryl glucopyranoside. Ursolic acid (1) was the only constituent that exhibited cytotoxic activity toward three human cancer cell lines in culture. This is the first phytochemical and cytotoxic analysis performed to this plant species.

Cytotoxic activity of moronic acid and identification of the new triterpene 3,4-seco-olean-18-ene-3,28-dioic acid from Phoradendron reichenbachianum

The cytotoxic compound moronic acid (1) and the new tetracyclic triterpene 3,4-seco-olean-18-ene-3,28-dioic acid (2), were isolated from the aerial parts of the medicinal plant Phoradendron reichenbachianum (mistletoe, Loranthaceae) through a bioassay-guided fractionation. In addition, squalene, glycerol trilinoleate, morolic acid, betulonaldehyde, betulinaldehyde, alpha-germanicol, lupeol, beta-sitosterol and beta-sitosteril glucopyranoside, were identified in this plant species. The structures were elucidated on the basis of chemical and spectroscopic evidence.

Cytotoxic isoflavans from Eysenhardtia polystachya

Two new cytotoxic isoflavans, (3S)-7-hydroxy-2',3',4',5', 8-pentamethoxyisoflavan (1) and (3S)-3',7-dihydroxy-2',4',5', 8-tetramethoxyisoflavan (2), were isolated from the bark and trunks of Eysenhardtia polystachya (Leguminosae), together with the known constituents stigmasterol, isoduartin, cuneatin, 7-hydroxy-2',4', 5'-trimethoxyisoflavone, and 3,4-dimethoxy-8, 9-(methylenedioxy)pterocarpan. The structures of 1 and 2 were elucidated on the basis of spectroscopic methods. The antimicrobial, cytotoxic, and insecticidal potential of some of these compounds were evaluated. The isoflavans 1, 2, and isoduartin (2', 7-dihydroxy-3',4',8-trimethoxyisoflavan) displayed moderate cytotoxic activity against KB cell lines.