Α-amyrin Acetate Research Articles

Phytochemical Studies of Alstonia scholaris, Chemical Transformation and Biological Evaluation against a Breast Cancer Cell Line

Background:: Some Alstonia species are used in traditional medicine to treat diseases such as cancer, dysentery, diarrhea, jaundice, malaria, gastrointestinal troubles, and snake-bites. Objective:: In this study, we aim to evaluate the ethanol leaf extract of Alstonia scholaris for anticancer constituents and structural modification to introduce a privilege medicinal α,β-unsaturated scaffold. Methods:: The relative viability of the MDA-MB-231 breast cancer cell line exposed to isolated compounds at different concentrations was assayed. Chemical analysis was carried out by high resolution mass spectrometry and one and two-dimensional NMR techniques. Results:: Structures of purified compounds were determined as betulin 1, α-amyrin acetate 2, mixture of β-sitosterol 3 and stigmasterol 4, tetratriacontyl-trans-p-coumarate 5, ursolic acid 6, β-sitosterol glucoside 7, picralstonine 8 and scholaricine 9. To introduce privilege medicinal scaffold, compounds 1 and 2 under SeO2 oxidation condition afford new acrylaldehye derivatines. Compound 1 afforded Betulin acrylaldehyde 10 while compound 2 afforded lupeolacetate acryl aldehyde 11 in an intriguing mechanism with the conversion of ursane to lupane scafford. Compound 11 equally showed interesting activity against MDA MB 231 breast cancer cell line with an IC50 of 4.63 ± 0.09 μg/ml. Conclusion:: From these findings, the medicinal α,β-unsaturated scaffold could have pharmacological effects in treating MDA-MB-231 breast cancer.

Antidiabetic Activity, Molecular Docking, and ADMET Properties of Compounds Isolated from Bioactive Ethyl Acetate Fraction of Ficus lutea Leaf Extract

Diabetes contributes to the rising global death rate. Despite scientific advancements in understanding and managing diabetes, no single therapeutic agent has been identified to effectively treat and prevent its progression. Consequently, the exploration for new antidiabetic therapeutics continues. This study aimed to investigate the antidiabetic bioactive ethyl acetate fraction of F. lutea at the molecular level to understand the molecular interactions and ligand-protein binding. To do this, the fraction underwent column chromatography fractionation to yield five compounds: lupeol, stigmasterol, α-amyrin acetate, epicatechin, and epiafzelechin. These compounds were evaluated in vitro through α-glucosidase inhibition and glucose utilization assays in C2C12 muscle and H-4-11-E liver cells using standard methods. In silico analysis was conducted using molecular docking and ADMET studies. Epicatechin exhibited the most potent α-glucosidase inhibition (IC50 = 5.72 ± 2.7 µg/mL), while epiafzelechin stimulated superior glucose utilization in C2C12 muscle cells (33.35 ± 1.8%) and H-4-11-E liver cells (46.7 ± 1.2%) at a concentration of 250 µg/mL. The binding energies of the isolated compounds for glycogen phosphorylase (1NOI) and α-amylase (1OSE) were stronger (<−8.1) than those of the positive controls. Overall, all tested compounds exhibited characteristics indicative of their potential as antidiabetic agents; however, toxicity profiling predicted epiafzelechin and epicatechin as better alternatives. The ethyl acetate fraction and its compounds, particularly epiafzelechin, showed promise as antidiabetic agents. However, further comprehensive studies are necessary to validate these findings.

Lipoxygenase inhibition and molecular docking studies of secondary metabolites from the leaves of Alstonia scholaris

The phytochemical study was carried out on the ethanolic extract of the leaves of Alstonia scholaris. This plant has been used traditionally for medicinal purposes in the treatment of several diseases such as cancer, jaundice, malaria, gastrointestinal troubles, dysentery, snake-bite and diarrhea. Chromatographic purification of this extract led to the isolation and characterization of nine compounds. Their structures were elucidated as betulin (1), α-amyrin acetate (2), mixture of β-sitosterol (3) and stigmasterol (4), tetratriacontyl-trans-p-coumarate (5), ursolic acid (6), picralstonine (7), β-sitosterol glucoside (8) and scholaricine (9). Scholaricine and β-sitosterol-glucoside exhibited potent lipoxygenase inhibitory activity with IC50 of 15.2 ​± ​0.41 and 18.5 ​± ​0.14 respectively compared to Baicalein (22.6 ​± ​0.08) used as positive control. Molecular docking studies were conducted to support lipoxygenase inhibitory activities of the test compounds.

De Novo Transcriptome Sequencing of Codonopsis lanceolata for Identification of Triterpene Synthase and Triterpene Acetyltransferase.

Codonopsis lanceolata (Campanulaceae) is a perennial plant commonly known as the bonnet bellflower. This species is widely used in traditional medicine and is considered to have multiple medicinal properties. In this study, we found that shoots and roots of C. lanceolata contained various types of free triterpenes (taraxerol, β-amyrin, α-amyrin, and friedelin) and triterpene acetates (taraxerol acetate, β-amyrin acetate, and α-amyrin acetate). The content of triterpenes and triterpene acetates by GC analysis was higher in the shoot than in the roots. To investigate the transcriptional activity of genes involved in triterpenes and triterpene acetate biosynthesis, we performed de novo transcriptome analysis of shoots and roots of C. lanceolata by sequencing using the Illumina platform. A total of 39,523 representative transcripts were obtained. After functional annotation of the transcripts, the differential expression of genes involved in triterpene biosynthetic pathways was investigated. Generally, the transcriptional activity of unigenes in the upstream region (MVA and MEP pathway) of triterpene biosynthetic pathways was higher in shoots than in roots. Various triterpene synthases (2,3-oxidosqualene cyclase, OSC) participate to produce triterpene skeletons by the cyclization of 2,3-oxidosqualene. A total of fifteen contigs were obtained in annotated OSCs in the representative transcripts. Functional characterization of four OSC sequences by heterologous expression in yeast revealed that ClOSC1 was determined as taraxerol synthase, and ClOSC2 was a mixed-amyrin synthase producing α-amyrin and β-amyrin. Five putative contigs of triterpene acetyltransferases showed high homology to the lettuce triterpene acetyltransferases. Conclusively, this study provides the basis of molecular information, particularly for the biosynthesis of triterpenes and triterpene acetates in C. lanceolata.

Mechanistic Insights into the Neuroprotective Potential of Sacred Ficus Trees.

Ficus religiosa (Bo tree or sacred fig) and Ficus benghalensis (Indian banyan) are of immense spiritual and therapeutic importance. Various parts of these trees have been investigated for their antioxidant, antimicrobial, anticonvulsant, antidiabetic, anti-inflammatory, analgesic, hepatoprotective, dermoprotective, and nephroprotective properties. Previous reviews of Ficus mostly discussed traditional usages, photochemistry, and pharmacological activities, though comprehensive reviews of the neuroprotective potential of these Ficus species extracts and/or their important phytocompounds are lacking. The interesting phytocompounds from these trees include many bengalenosides, carotenoids, flavonoids (leucopelargonidin-3-O-β-d-glucopyranoside, leucopelargonidin-3-O-α-l-rhamnopyranoside, lupeol, cetyl behenate, and α-amyrin acetate), flavonols (kaempferol, quercetin, myricetin), leucocyanidin, phytosterols (bergapten, bergaptol, lanosterol, β-sitosterol, stigmasterol), terpenes (α-thujene, α-pinene, β-pinene, α-terpinene, limonene, β-ocimene, β-bourbonene, β-caryophyllene, α-trans-bergamotene, α-copaene, aromadendrene, α-humulene, alloaromadendrene, germacrene, γ-cadinene, and δ-cadinene), and diverse polyphenols (tannin, wax, saponin, leucoanthocyanin), contributing significantly to their pharmacological effects, ranging from antimicrobial action to neuroprotection. This review presents extensive mechanistic insights into the neuroprotective potential, especially important phytochemicals from F. religiosa and F. benghalensis. Owing to the complex pathophysiology of neurodegenerative disorders (NDDs), the currently existing drugs merely alleviate the symptoms. Hence, bioactive compounds with potent neuroprotective effects through a multitarget approach would be of great interest in developing pharmacophores for the treatment of NDDs.

Exploration of anti-inflammatory activity of extract and isolated compounds obtained from the aerial root of Ficus benghalensis Linn.

Ficus benghalensis L. is a traditional heritage tree available in Indian subcontinent and used traditionally for ailment of several diseases. Present study designed to purify and characterize the bioactive moiety (s) from the aerial root part of the plant, and assessment of the role of extract as well as purified molecules in the prevention of inflammation. Aerial root portion of the plant was first extracted using methanol as solvent, and further fractionated with n-hexane and ethyl acetate. α amyrin acetate (S1) was purified from the n-hexane and ethyl acetate fraction, and stigmasterol (S2), first time purified from the plant using from the ethyl acetate fraction using column chromatography. Extract, purified α-amyrin acetate and stigmasterol were checked for their anti-inflammatory property using Carrageenan induced paw oedema model on rat. Extract at a dose 400 mg/kg, α-amyrin acetate and stigmasterol both at 100 mg /kg dose significantly reduce the inflammation near to normal. After 3 hrs the paw volume was inhibited 25%, 47.5%, 42.5%, 45%, 62.5% by EA extract of 200 mg/kg, 400 mg/kg, stigmasterol 100mg/kg, α- amyrin acetate 100 mg/kg and standard Indomethacin, respectively. The finding of present study revealed the prospective anti-inflammatory property of α-amyrin acetate, stigmasterol and extract of aerial root of Ficus benghalensis L.

Phytochemical Screening, GC-MS & HPLC Analysis of Decalepis arayalpathra (Joseph & Chandras) an Endangered Medicinal Plant

Decalepis arayalpathra is one of the important medicinal plants with milky latex, which grows on the exposed rocky slopes at an
 800-1200 m elevation. It is endemic to the southern region of the Western Ghats chiefly in the Agasthyamalai region of Tamil Nadu. The plant
 has been used by traditional people to treat various diseases such as peptic ulcers, cancer like affliction, skin diseases etc. The moniliform tuberous roots have special fragrance like vanilla, because the roots contain different compounds such as α-amyrin acetate, ß-sitosterol, naringenin, kaempferol and aromadendrin especially in 2-hydroxy 4-methoxy benzaldehyde (2H4MB). The present study was aimed to examine the phytochemical screening and identification of bioactive compounds of Decalepis arayalpathra by GC-MS & HPLC analysis. The phytochemical analysis was carried out by using standard methods. Preliminary phytochemical screening showed major bioactive compounds such as alkaloids, flavonoids, proteins, steroids, terpenoids, quinones, resins, phenols, tannins, volatile oils and other phytocompounds. FTIR analysis identified various bioactive components and those were confirmed through GC-MS analysis. 2-hydroxy 4-methoxybenzaldehyde (2H4MB) and ß-sitosterol were quantified by HPLC analysis. Further studies have to be carried out in the in-vitro multiplication, isolation and characterization of compounds to enhance the root flavouring complexes for medicinal, food and beverage industries.

ISOLATION AND CHARACTERISATION OF ALPHA AND BETA AMYRINS FROM PROPOLIS OBTAINED FROM BENUE STATE

Chemical composition of propolis has been reported to be phyto-geographical in nature. The aim of this study was to isolate and characterize chemical compounds from hexane and ethyl acetate extract of propolis obtained from Gboko. To isolate compounds, extract was subjected to column chromatography by gradient elution using two solvent mixtures - hexane: ethyl acetate and ethyl acetate: methanol. The structure of the isolated compound was established using 1H-NMR and further verification of data on the compound by comparison with literature reports. α-amyrin, β-amyrin, α-amyrin acetate and β-amyrin acetate, known pharmacologically active pentacyclic triterpenoids, were isolated from the hexane and ethyl acetate extract of this propolis.

Characterization of a Pentacyclic Triterpene Acetyltransferase Involved in the Biosynthesis of Taraxasterol and ψ-Taraxasterol Acetates in Lettuce.

Triterpenoids exist in a free state and/or in conjugated states, such as triterpene glycosides (saponins) or triterpene esters. There is no information on the enzyme participating in the production of triterpene esters from free triterpenes. Lettuce (Lactuca sativa) contains various pentacyclic triterpene acetates (taraxasterol acetates, ψ-taraxasterol acetates, taraxerol acetates, lupeol acetates, α-amyrin acetates, β-amyrin acetates, and germanicol acetate). In this study, we report a novel triterpene acetyltransferase (LsTAT1) in lettuce involved in the biosynthesis of pentacyclic triterpene acetates from free triterpenes. The deduced amino acid sequences of LsTAT1 showed a phylogenetic relationship (43% identity) with those of sterol O-acyltransferase (AtSAT1) of Arabidopsis thaliana and had catalytic amino acid residues (Asn and His) that are typically conserved in membrane-bound O-acyltransferase (MBOAT) family proteins. An analysis of LsTAT1 enzyme activity in a cell-free system revealed that the enzyme exhibited activity for the acetylation of taraxasterol, ψ-taraxasterol, β-amyrin, α-amyrin, lupeol, and taraxerol using acetyl-CoA as an acyl donor but no activity for triterpene acylation using a fatty acyl donor. Lettuce oxidosqualene cyclase (LsOSC1) is a triterpene synthase that produces ψ-taraxasterol, taraxasterol, β-amyrin and α-amyrin. The ectopic expression of both the LsOSC1 and LsTAT1 genes in yeast and tobacco could produce taraxasterol acetate, ψ-taraxasterol acetate, β-amyrin acetate, and α-amyrin acetate. However, expression of the LsTAT1 gene in tobacco was unable to induce the conversion of intrinsic sterols (campesterol, stigmasterol, and β-sitosterol) to sterol acetates. The results demonstrate that the LsTAT1 enzyme is a new class of acetyltransferase belong to the MBOAT family that have a particular role in the acetylation of pentacyclic triterpenes and are thus functionally different from sterol acyltransferase conjugating fatty acyl esters.

Deciphering the sensing of α-amyrin acetate with hs-DNA: a multipronged biological probe.

In this study, we focus on the biomimetic development of small molecules and their biological sensing with DNA. The binding of herring sperm deoxyribonucleic acid (hs-DNA) with naturally occurring bioactive small molecule α-amyrin acetate (α-AA), a biomimetic – isolated from the leaves of Ficus (F.) arnottiana is investigated. Collective information from various imaging, spectroscopic and biophysical experiments provides evidence that α-AA is a minor groove sensor of hs-DNA and preferentially binds to the A–T-rich regions. Interactions of different concentrations of small molecule α-AA with hsDNA were evaluated via various analytical techniques such as UV-Vis, circular dichroism (CD) and fluorescence emission spectroscopy. Fluorescence emission spectroscopy results suggest that α-AA decreases the emission level of hsDNA. DNA minor groove sensor Hoechst 33258 and intercalative sensor EB, melting transition analysis (TM) and viscosity analysis clarified that α-AA binds to hs-DNA via a groove site. Biophysical chemistry and molecular docking studies show that hydrophobic interactions play a major role in this binding. The present research deals with a natural product biosynthesis-linked chemical–biology interface sensor as a biological probe for α-AA: hs-DNA.

PHYTOCHEMICAL STUDY OF PETROLEUM ETHER EXTRACT OF STEM BARK OF BOMBAX MELABARICUM

Bombax melabaricum DC. is a medium sized tree and distributed mainly in tropical areas of China and hotter part of India. It is used as medicinal herbs. Objective of the study was to isolate active phytochemicals from stem bark of title Plant. Plant Extract of stem bark was chromatographed over silica gel column and eluted with different solvents. Characterization of isolated compounds was done on the basis of spectral studies. Lupeol (I), stigmasterol (II), α-amyrin acetate (III) and trans-triacontanyl-4-hydroxy-3-methoxycinnamate (IV) were isolated. These compounds have very useful medicinal activities. Present work gives a direction for future investigators to get some medicinally important drugs.

BIOCHEMICAL PROFILE OF Calotropis procera FLOWERS

Calotropis procera is a medicinal weed of family Asclepiadaceae. This study was carried out to explore the biochemical profile of C. procera flowers collected from Southern Punjab region of Pakistan. Methanolic flower extract of C. procera was subjected to GC-MS analysis. There were 30 compounds identified in this extract. The predominant compound was γ-sitosterol with 15.39% peak area. Other abundantly occurring compounds included stigmasterol (9.22%), 9,12-octadecadienoic acid (Z,Z)-, methyl ester (9.01%), campesterol (8.63%), α-amyrin acetate (8.25%), β-amyrin (8.09%), hexadecanoic acid, methyl ester (7.91%), 11-octadecenoic acid, methyl ester (6.15%), and 2-methoxy-4-vinylphenol (5.66%). Moderately abundant compounds included nonacos-1-ene (2.83%), methyl stearate (1.57%), pentacosane (1.44%), phytol (1.33%), heptacos-1-ene (1.20%), heneicosane (1.19%), and 1-hexacosene (1.09%). The remaining less abundant compounds were present with peak areas less than 1%. Literature survey showed that the major compounds identified in the flower extract of C. procera possess various bioactivities including antidiabetic, anticancer, antihyperglycemic, antioxidant, antimicrobial and anti-inflamatory.

Molecular Docking and Molecular Dynamics Simulation Studies of Triterpenes from Vernonia patula with the Cannabinoid Type 1 Receptor.

A molecular docking approach was employed to evaluate the binding affinity of six triterpenes, namely epifriedelanol, friedelin, α-amyrin, α-amyrin acetate, β-amyrin acetate, and bauerenyl acetate, towards the cannabinoid type 1 receptor (CB1). Molecular docking studies showed that friedelin, α-amyrin, and epifriedelanol had the strongest binding affinity towards CB1. Molecular dynamics simulation studies revealed that friedelin and α-amyrin engaged in stable non-bonding interactions by binding to a pocket close to the active site on the surface of the CB1 target protein. The studied triterpenes showed a good capacity to penetrate the blood–brain barrier. These results help to provide some evidence to justify, at least in part, the previously reported antinociceptive and sedative properties of Vernonia patula.

CHEMICAL AND BIOLOGICAL ANALYSIS OF THE BIOCTIVE FRACTIONS OF THE LEAVES OF SCAEVOLA TACCADA (GAERTN.) ROXB

Objective: Scaevola taccada. (Gaertn.) Roxb. is widely dispersed all along the coasts of Africa. It is used in folk medicine for diversity of ailments. This study aims to investigate the major phytoconstituents and biological activities of the leaves of S. taccada (Gaertn.) Roxb.
 Methods: In vitro biological examination viz. antimicrobial, cytotoxic and antioxidant activities of the ethanol extract of the leaves (EE) and its fractions; (petroleum ether (PE), methylene chloride (MC), ethyl acetate (EA) and n-butanol(BuOH)) were carried out. Estimation of the phytochemicals of biologically active fractions was done.
 Results: n-butanol fraction displayed remarkable antimycobacterium activity. Petroleum ether as well as n-butanol fractions evidenced a cytotoxic effect on breast carcinoma cell line (MCF7) and colon carcinoma cell line (HCT) with IC50 11.7 and 15.04 µg/ml respectively. Moreover, ethyl acetate fraction exhibits an antioxidant effect with EC50 476.7±0.57 µg/ml. n-tetradecane 1, α-amyrin palmitate 2, α-amyrin acetate 3, α-amyrin 4, stigmasterol 5, luteolin-7-O-β-glucoside 6, rutin 7 and alidyjosioside 8 were identified in S. taccada (Gaertn.) Roxb. leaves.
 Conclusion: Petroleum ether fraction is a cytotoxic candidate, especially against (MCF-7). It exhibited a moderate antifungal and antibacterial against certain Gram-positive bacteria. Ethyl acetate showed an antioxidant effect along with moderate antifungal activity. n-butanol fraction exerted potential antimycobacterial, significant cytotoxic activity against (HCT), good antifungal and antibacterial against Gram-positive and Gram-negative bacteria. Stigmasterol, luteolin-7-O-β-glucoside, rutin and alidyjosioside were isolated for the first time from S. taccada (Gaertn.) Roxb. Leaves.

АНТИМИКРОБНАЯ АКТИВНОСТЬ И ФИТОТОКСИЧНОСТЬ ЭКСТРАКТОВ НЕКОТОРЫХ ВИДОВ РАСТЕНИЙ РОДА CENTAUREA

The article presents data on the phytochemical composition and biological activity of extracts of plants of the genus Cornflower (Centaurea L.) - blue cornflower (Centaurea cyanus L.), meadow cornflower (Centaurea jacea L.), rough cornflower (Centaurea scabiosa L.), which are typical representatives flora of the middle zone of the Russian Federation, to assess the potential effectiveness of their use as plant protection drugs against phytopathogenic infections. The ethanol extracts were obtained by maceration of freshly harvested flowers, followed by filtration of the extract and concentration with the help of a rotary evaporator. The chemical composition of ethanol extracts was studied with the help of the gas chromatography/mass spectrometry (GC/MS) method. The qualitative and quantitative composition of the components differed depending on the plant types. The largest number of compounds was identified in the plant extract of cornflower rough, the seven components prevailing – coumaran, L-arctigenin, stigmasterol, γ-sitosterol, α-amyrin, β-amyrin and tocopherol acetate. The bacteriostatic, bactericidal and fungicidal properties of the extracts varied over a wide concentration range of 0.6...20 mg/ml. The highest indicators of antibacterial activity were found in the rough cornflower - the minimum inhibiting and bactericidal concentrations were 0.6…5 mg/ml, the lowest in the meadow cornflower - 5...20 mg/ml, respectively. Clavibacter michiganensis was characterized by the highest sensitivity to the components of plant extracts. In the case of the phytopathogenic fungus, the growth-inhibiting antimicrobial activity of cornflower extracts was the same for all studied species, and the fungicidal activity was most pronounced in the meadow cornflower - the effective concentration was 1 mg/ml. Presowing treatment with ethanol extracts had an inhibitory effect on the germination of test plant seeds: at a concentration of 1 mg/ml, the germination of watercress decreased by 8...42% compared to the control, 10 mg/ml - by 30...100%. Presowing seed treatment inhibited the linear growth of watercress roots by 35...52% and the accumulation of raw biomass of seedlings and roots by 23...89%.

Phytochemical and Biological Studies of Carissa macrocarpa, F. Apocyanaceae

The present work comprises the isolation, purification and identification of eight known compounds obtained from the powdered leaves & stems of Carissa macrocarpa (F. Apocyanaceae) named; α-amyrin acetate (1), α-amyrin (2), lupeol acetate (3), stearic acid (4), ursolic acid (5), β-sitosterol-3-O-β-D-glucopyranoside (7), quercetin (7) and kaempferol-3-O-rutinoside (8). The structural elucidations of the isolated compounds were confirmed on the basis of their physical, chemical, chromatographic and spectroscopic methods. In addition; the study of some biological activities of Carissa macrocarpa 70% methanolic extract (CMME) and its fractions (n-hxane, dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol). The biological evaluations included cardiovascular activity, together with anti-inflammatory & antipyretic and antimicrobial activities. CMME and its fractions showed promising increase in the force of contractility (positive inotropic effect) and decrease in the heart rates (negative chronotropic effect) of the isolated rabbit's heart. They showed hypotensive effect on the rabbits mean arterial blood pressure (MABP). The EtOAc and DCM fractions showed the maximum anti-inflammatory activity after 5 h. (100 mg/kg) with percentage of inhibition 43% and 41%, respectively, in comparison with indomethacin reference drug (47%, 10 mg/kg). Yeast-induced hyperpyrexia method was used for antipyretic activity. The CMME and n-butanol fraction showed the highest antipyretic activity after 5 h. The CMME and fractions provided remarkable antibacterial activity. The EtOAc fraction showed the most potent effect against the tested microorganisms Bacillus subtilis & Staphylococcus aureus (Gram +ve bacteria) and Escherichia coli & Pseudomonas aeruginosa (Gram -ve bacteria).

Antimicrobial evaluation of Amyrin acetate from the stem bark of Ficus sycomorus (Moraceae)

In this study, the antimicrobial evaluation of alpha Amyrin obtained from the stem bark of ficus sycomorus was reported. Standard method was adopted for the screening of phyto-chemicals, while a combination of column and preparative thin layer chromatography lead to the compound (FA) a light yellow crystal. The compound FA showed significant inhibition on the tested organisms, E.coli (IC50 = 0.81) S. typhi (IC50= 0.84) S. aureus (IC50= 0.66) K. Pneumonia (IC50= 0.06) and was identified based on spectra evidence to contain a mixture of α-amyrin acetate.

Phytochemical analysis and antimicrobial activity of Enicostemma littorale

Antimicrobial resistance has risen in morbidity and mortality due to delay in medical care and rising health care costs. The aims and objectives of this study were to explore plant molecular entities from Enicostemma littorale by isolation, fractionation and antimicrobial activity using four different bacterial strains, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis followed by the establishment of their chemical identity in order to pave the way for potential advancement of plant-based pure therapies for application in the production of new drugs. The ethyl acetate extract was found to possess significant antimicrobial activity when compared to other extracts an attempt was made to fractionate these extracts by column chromatography. On the bases of spectroscopic data IR, NMR and MS and comparing the data in the scientific literature, the chemical structure of the isolated are luteolin (1) and α-amyrin acetate (2). Both isolated compounds showed the highest antibacterial effect, with minimum inhibitory concentration values ranging from 16 to 500 μg/mL, against Gram-positive and Gram negative bacteria, respectively.

Antioxidant Activity and Chemical Constituents from Stem Bark of Ficus abutilifolia. Miq (Moraceae)

Aims: The present study was conducted to determine the antioxidant activity and chemical components of Ficus abutilifolia. Miq. (Moraceae).
 Place and Duration of the Study: The study were performed at Department of chemistry, University of Ngaoundere, Cameroon, between July 2017 and September 2018.
 Methodology: Phytochemical study was carried out on all extracts of stem barks. Besides, the total phenols contents (TPC) using the Folin-Ciocalteu and the antioxidant activities using DPPH and FRAP methods were also evaluated. The isolation of compounds from the EtOAc extract was done using column and thin layer chromatographic techniques on silica gel. The structures of isolated constituents were elucidated using mass spectrometry, 1D and 2D-NMR techniques.
 Results: Phytochemical screening revealed that all the compounds tested were found to be present in the acetone extract; the hexane extract was the poorest in compounds. Acetone extract, DCM/MeOH (1:1) and MeOH extracts were found to be rich in phenols with TPC respectively (239. 849 ± 0.969), (232.676 ± 0.404) and (109.654 ± 0.724) mg EAG/100g EX. Except the n-hexane extract, all the others exhibit antioxidant activities, acetone extract being the most effective with an inhibitory concentration 50 (IC50) of (0.038 ± 0.002) mg/mL for the DPPH antiradical scavenging activity and (0,021 ± 0,002) mg/mL for FRAP. A new fatty acid named Pentacosyl henicosanoate (2) along with six known compounds Octatriacontane (1), β–sitosterol (3), a mixture of Lupeol acetate (4a), α-amyrin acetate (4b), β-amyrin acetate (4c) and Daucosterol (5) were isolated from the column chromatography of the ethyl acetate extract. Daucosterol (5) exhibited antiradical activity with an IC50 of (13.005 ± 0.005) mg/mL. Only Daucosterol (5) has exhibited antiradical activity with an IC50 of (13.005 ± 0.005) mg/mL among the isolated compounds.
 Conclusion: This study provides scientific evidence and support for the traditional uses of F. abutilifolia stem barks in the treatment of diseases associated with oxidative stress.

Chemical constituents of Ocimum kilimandscharicum Guerke acclimatized in Kakamega Forest, Kenya

The genus Ocimum belongs to the Lamiaceae family and is made of almost 200 species of herbs and shrubs which have potential medicinal properties. The species are native to the tropical and temperate climate zones around the globe. Two new compounds with damarane skeleton namely 2α-hydroxy-3-oxodammara-20,24-diene (1) and 2α,3β-dihydroxy dammara-20, 24-diene (2) together with apeginin7-O-neohespeiridoside (3), quercetin (4), turkesterone (5), fesitin (6), apeginin (7), chrysin (8), lupeol (9), stigmasterol (10), friedelin (11), α-amyrin acetate (12) and n-octacosonoic acid (13) are reported here from the leaves of Ocimum kilimandscharicum. Their structures were established on the basis of physical and spectroscopic analyses and by comparison with the literature data. Crude extracts and isolated compounds were investigated for contact toxicity and anti-feedant activity against Sitophilus zeamais and Prostephanus truncatus. KEY WORDS: Ocimum kilimandscharicum, Lamiaceae, Contact toxicity, Anti-feedant activity, Acclimatized Bull. Chem. Soc. Ethiop. 2019, 33(3), 527-539. DOI: https://dx.doi.org/10.4314/bcse.v33i3.13