Two new steroidal saponins from dried fermented residues of leaf-juices of Agave sisalana forma Dong No. 1

Steroidal constituents from Solanum nigrum

Three previously undescribed steroidal constituents including two sterols (1-2) and one pregnane-type steroidal glycoside (6), along with nineteen known ones (3-5, 7-22), were isolated from the 80% alcohol extraction of Solanum nigrum L. Their structures and the absolute configurations were established by analysis of the extensive spectroscopic data (1H/13 NMR, 1H1H COSY, HSQC, HMBC, and NOESY), and/or by comparisons of the experimental electronic circular dichroism (ECD) spectra with those calculated ones by TDDFT method. Further, a MTT assay was applied to demonstrate that compounds 1-4, 6-12, 18, and 22 exhibited significant cytotoxic activities against SW480 cells, and compounds 1-4, 6-14, and 16-22 showed significant cytotoxic activities against Hep3B cells.

Structural characterization of three cytotoxic steroidal saponins from the leaves of Agave desmetiana hort

Three steroidal saponins detected by LC-MS were isolated from the leaves of Agave desmetiana hort. The three saponins were characterized as; Tigogenin 3 - [{O - β - D - xylopyranosyl (1 → 2) - α - L-rhamnopyranosyl (1 → 3)}-β-D- glucopyranoside), Tigogenin- 3 - ([O- α -L-rhamnopyranosyl (1 → 3) - β - D - glalactopyranosyl (1 → 2)] - β - D - glucopyranoside) and Tigogenin- 3 - ([{O - α - L - rhamnopyranosyl (1 → 4)} - β - D - galactopyranosyl (1 → 3) - β - D - xylopyranosyl (1 → 2)] - β - D - glucopyranoside). Identification and structure elucidation of the isolates were done via 1D and 2D NMR techniques, and chemical methods. Cytotoxic activity for the crude saponins and the three isolated compounds were evaluated against Hepg-2 and Mcf-7 cell lines. Compound 2 proved to be the most cytotoxic against tested cell lines with an IC₅₀ 2.97 and 2.49 μg/ml respectively.

Saponins of Agave: Chemistry and bioactivity

The genus Agave comprises more than 400 species with geographical presence in the tropical and sub-tropical regions of the world. These plants have a rich history of folkloric use and are known for a wide spectrum of applications. Secondary metabolites of diverse chemical classes have been reported from Agave species. Owing to their pharmacological significance, the steroidal saponins of Agave have caught the attention of phytochemists, biologists and drug discovery scientists. The present review describes 141 steroidal saponins and sapogenins and covers the literature published from 1970 to 2015. It is a comprehensive and coherent presentation of the structures, methods of chemical profiling, structure elucidation and biological activities of the saponins and sapogenins reported from Agave. The article provides a perspective of the research on steroidal compounds of Agave.

Chemicals from Agave sisalana biomass: isolation and identification

Agave sisalana (sisal) is known worldwide as a source of hard fibers, and Brazil is the largest producer of sisal. Nonetheless, the process of removing the fibers of the sisal leaf generates 95% waste. In this study, we applied chemical sequential steps (hydrothermal extraction, precipitation, liquid-liquid extraction, crystallization, SiO2 and Sephadex LH 20 column chromatography) to obtain pectin, mannitol, succinic acid, kaempferol and a mixture of saponins as raw chemicals from sisal biomass. The structural identification of these compounds was performed though spectrometric methods, such as Infrared (IR), Ultraviolet (UV), Mass spectrometry (MS) and Nuclear magnetic resonance (NMR). All the sisal chemicals found in this work are used by both the chemical and pharmaceutical industries as excipients or active principles in products.

Biotransformation of steroidal saponins in sisal (Agave sisalana Perrine) to tigogenin by a newly isolated strain from a karst area of Guilin, China

A rod-shaped bacterium was isolated from the soil in a karst area of Guilin, China and its biotransformation of steroidal saponins in sisal (Agave sisalana Perrine) to tigogenin was presented for the first time. A total of 22 strains for the degradation of steroidal saponins in sisal were isolated from 48 soil samples, and the isolated rod-shaped, bacterial strain ZG-21 was used for the production of tigogenin due to its highest degradation efficiency of steroidal saponins in sisal. The parameters affecting biotransformation by strain ZG-21 were optimized. Under the optimized conditions of temperature (30 °C), pH (6), time (5 days) and substrate concentration (5 mg/mL), a maximum tigogenin yield of 26.7 mg/g was achieved. Compared with the conventional method of acid hydrolysis, the biotransformation method provided a clean and eco-friendly alternative for the production of tigogenin.

Bioactive steroidal saponins from Agave offoyana flowers

Bioguided studies of flowers of Agave offoyana allowed the isolation of five steroidal saponins never described previously, Magueyosides A-E (1-5), along with six known steroidal saponins (6-11). The structures of compounds were determined as (25R)-spirost-5-en-2α,3β-diol-12-one 3-O-{β-d-xylopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (1), (25R)-spirost-5-en-2α,3β-diol-12-one 3-O-{β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (2), (25R)-spirost-5-en-2α,3β,12β-triol 3-O-{β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (3), (25R)-5α-spirostan-2α,3β-diol-12-one 3-O-{β-d-xylopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (4), and (25R)-5α-spirostan-2α,3β-diol-9(11)-en-12-one 3-O-{β-d-xylopyranosyl-(1→3)-O-β-d-glucopyranosyl-(1→2)-O-[β-d-xylopyranosyl-(1→3)]-O-β-d-glucopyranosyl-(1→4)-O-β-d-galactopyranoside} (5), by comprehensive spectroscopic analysis, including one- and two-dimensional NMR techniques, mass spectrometry and chemical methods. The bioactivities of the isolated compounds on the standard target species Lactuca sativa were evaluated. A dose-dependent phytotoxicity and low dose stimulation were observed.

Anti-inflammatory activity of different agave plants and the compound cantalasaponin-1

Species of the agave genus, such as Agave tequilana, Agave angustifolia and Agave americana are used in Mexican traditional medicine to treat inflammation-associated conditions. These plants' leaves contain saponin compounds which show anti-inflammatory properties in different models. The goal of this investigation was to evaluate the anti-inflammatory capacity of these plants, identify which is the most active, and isolate the active compound by a bio-directed fractionation using the ear edema induced in mice with 12-O-tetradecanoylphorbol-13-acetate (TPA) technique. A dose of 6 mg/ear of acetone extract from the three agave species induced anti-inflammatory effects, however, the one from A. americana proved to be the most active. Different fractions of this species showed biological activity. Finally the F5 fraction at 2.0 mg/ear induced an inhibition of 85.6%. We identified one compound in this fraction as (25R)-5α-spirostan-3β,6α,23α-triol-3,6-di-O-β-D-glucopyranoside (cantalasaponin-1) through 1H- and 13C-NMR spectral analysis and two dimensional experiments like DEPT NMR, COSY, HSQC and HMBC. This steroidal glycoside showed a dose dependent effect of up to 90% of ear edema inhibition at the highest dose of 1.5 mg/ear.

Ethnoknowledge of Bukusu community on livestock tick prevention and control in Bungoma district, western Kenya

ETHNOPHARMACOLOGICAL RELEVANCE

To date, nomadic communities in Africa have been the primary focus of ethnoveterinary research. The Bukusu of western Kenya have an interesting history, with nomadic lifestyle in the past before settling down to either arable or mixed arable/pastoral farming systems. Their collective and accumulative ethnoveterinary knowledge is likely to be just as rich and worth documenting.

AIM OF THE STUDY

The aim of the present study was to document indigenous knowledge of the Bukusu on the effect of livestock ticks and ethnopractices associated with their management. It was envisaged that this would provide a basis for further research on the efficacy of these practices that could also lead to the discovery of useful tick-control agents.

MATERIALS AND METHODS

Non-alienating, dialogic, participatory action research (PAR) and participatory rural appraisal (PRA) approaches involving 272 women and men aged between 18 and 118 years from the Bukusu community were used.

RESULTS

Ticks are traditionally classified and identified by colour, size, host range, on-host feeding sites, and habitat preference. Tick-associated problems recognised include kamabumba (local reference to East Coast fever, Anaplasmosis or Heartwater diseases transmitted by different species of livestock ticks) and general poor performance of livestock. Traditional methods of controlling ticks include handpicking, on-host use of ethnobotanical suspensions (prepared from one or more of over 150 documented plants) to kill the ticks and prevent re-infestation, fumigation of infested cattle with smoke derived from burning ethnobotanical products, burning pastures, rotational grazing ethnopractices, and livestock quarantine.

CONCLUSIONS

The study confirms that the Bukusu have preserved rich ethnoveterinary knowledge and practices. It provides some groundwork for elucidating the efficacy of some of these ethnopractices in protecting livestock from tick disease vectors, particularly those involving the use of ethnobotanicals, which may lead to the discovery of useful ant-tick agents.

Steroidal saponins from the whole plants of Agave utahensis and their cytotoxic activity

Phytochemical investigation of the whole plants of Agave utahensis Engelm. (Agavaceae) has resulted in the isolation of 15 steroidal saponins (1-15), including five spirostanol saponins (1-5) and three furostanol saponins (11-13). Structures of compounds 1-5 and 11-13 were determined by spectroscopic analysis and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HL-60 human promyelocytic leukemia cells.

Steroidal Saponins and Sapogenins from the Agavaceae Family

Plants belonging to the family Agavaceae are used in folkloric medicinal practices worldwide and chemical investigations of these plants have shown that they are an abundant source of steroidal saponins and sapogenins. Despite the large number of secondary metabolites isolated from this family so far, there have been few reports on the bioactivity of these compounds. This article provides a comprehensive review of the steroidal constituents of plants from the genera Agave, Cordyline, Dracaena, Furcraea, Nolina, Sansevieria and Yucca up to June 2006, and reports on the bioactivity of these compounds where available.

The NMR studies on two new furostanol saponins from Agave sisalana leaves

The detailed NMR studies and full assignments of the 1H and 13C spectral data for two new furostanol saponins isolated from Agave sisalana leaves are described. Their structures were established using a combination of 1D and 2D NMR techniques including 1H, 13C, 1H-1H COSY, TOCSY, HSQC, HMBC and HSQC-TOCSY, and also FAB-MS spectrometry and chemical methods. The structures were established as (25S)-26-(beta-D-glucopyranosyl)-22 xi-hydroxyfurost-12-one-3beta-yl-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galacto- pyranoside (1) and (25S)-26-(beta-D-glucopyranosyl)-22xi-hydroxyfurost-5-en-12-one-3beta-yl-O-alpha-L-rhamno- pyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl- (1-->4)-beta-D-galactopyranoside (2).

A new steroidal saponin from Agave attenuata

A new steroidal saponin was isolated from the leaves of Agave attenuata. Its structure was established as (3beta,beta,25S)-spirostan-3-yl O-beta-D-glucopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 2)-O-[beta-D-glucopyranosyl-(1 --> 3)]-beta-D-glucopyranosyl-(1 --> 4)-beta-D-galactopyranoside. The structural identification was performed using detailed analyses of 1H- and 13C-NMR spectra including 2D NMR spectroscopic techniques (COSY, HETCOR, and COLOC) and chemical conversions. The hemolytic activity of the steroidal saponin was evaluated using an in vitro assay.

A new steroidal saponin fromAgave shrevei

A new steroidal saponin was isolated from the leaves of Agave shrevei. Its structure was established as 3-[O-beta-D-glucopyranosyl-(1-->2)-O-[O-beta-D-glucopyranosyl-(1-->4)-O-[O-beta-D-glucopyranosyl-(1-->6)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranosyl)-oxy]-(3beta,5alpha,25R)-spirostane. The structural identification was performed using detailed analyses of 1H- and 13C-NMR spectra including 2D NMR spectroscopic techniques (COSY, HETCOR, HMBC, and HMQC) and chemical conversions. The haemolytic activity of the steroidal saponin was evaluated using an in vitro assay.

Four New Steroid Constituents from the Waste Residue of Fibre Separation from Agave americana Leaves

Three new steroidal saponins, named agamenosides H-J (1-3), and a new cholestane steroid agavegenin D (4) were isolated from the waste residue of fibre separation from Agave americana leaves, together with six known steroids. Structures of the new compounds 1-4 were deduced to be (22S,23S,24R,25S)-24-[(beta-D-glucopyranosyl)oxy]-5alpha-spirostane-3beta,6alpha,23-triol 6-O-beta-D-glucopyranoside (1), (22S,23S,24R,25S)-5alpha-spirostane-3beta,23,24-triol 24-O-beta-D-glucopyranoside (2), (22S,23S,25R,26S)-23,26-epoxy-5alpha-furostane-3beta,22,26-triol 26-O-beta-D-glucopyranoside (3), and (22S,25S)-5alpha-cholestane-3beta,16beta,22,26-tetrol (4), respectively, by means of spectroscopic analysis, including extensive 1D and 2D NMR data, and the results of hydrolytic cleavage.