A new isoflavanone from the stem bark of Erythrina latissima

Two isoflavonoids--including the new compound 5,7-dihydroxy-2',4',5'-trimethoxyisoflavanone (1)--six flavanones and a feruloyl ester were isolated from the stem bark of Erythrina latissima.     

Antimicrobial diterpenes from the stem bark of Mitrephora celebica

Four diterpenes were isolated from the stem bark of Mitrephora celebica through bioassay-guided fractionation. Ent-trachyloban-19-oic acid (1) and ent-kaur-16-en-19-oic acid (2) were identified as the compounds responsible for the antimicrobial activity of the plant against methicillin-resistant Staphylococcus aureus and Mycobacterium smegmatis. 8(14),15-pimaradien-18-oic acid (3) and 7,15-pimaradien-18-oic acid (4) were isolated from the same fraction and were inactive against the microorganisms.     

Antimicrobial activity of Boswellia dalziellii stem bark.

The methanol and aqueous extracts of Boswellia dalziellii stem bark showed broad spectrum inhibiting activity against bacteria, both Gram-positive and Gram-negative, and fungi.     

Antimicrobial properties of Uvaria chamae stem bark

The antimicrobial properties of the methanol extract of Uvaria chamae stembark (ME) were investigated. The more active ethylacetate-soluble fraction (EAS) was separated by PTLC into 18 sub-fractions. Following phytochemical and antimicrobial screening, several sub-fractions, testing positive for the presence of glycosides (8, 11–15) and tannins (18), exhibited activity against a number of microorganisms, being in some cases more active than penicillin G and chloramphenicol.     

Antimicrobial and cytotoxicity evaluation of Buchholzia coriacea stem bark

Fractions prepared from the methanol extract of Buchholzia coriacea stem bark exhibited a high concentration-dependent antibacterial and antifungal activity compared to the standard antibiotics, ampicillin and tioconazole. In the brine shrimp lethality (BSL) assay, the methanol extract was found to be non-toxic with an LC(50) of 1031 microg/ml. The two main compounds present in the most active fraction were isolated and identified as lupeol and beta-sitosterol.     

Neolignans and flavonoids from the root bark of Illicium henryi

Two new neolignans (1 and 2) were isolated from the root bark of Illicium henryi, along with four known neolignans and seven known flavonoids (3–13). Their structures were elucidated on the basis of spectroscopic and chemical methods. The absolute configurations of compounds 1 and 2 were determined by the CD spectrum.     

Four new prenylated flavonoids and xanthones from the root bark of Artocarpus nobilis

Chemical investigation of the n-butanol extract from the methanol extract of the root bark of Artocarpus nobilis furnished four new prenylated flavonoids together with artonin E 2'-methylether (4), isoartonin E 2'-methylether (5), dihydroisoartonin E 2'-methylether (6), artonin V 2'-methylether (7), artobiloxanthone (1), artonin E (2) and cycloartobiloxanthone (3). All these compounds showed strong radical scavenging properties towards DPPH radical.     

Antimicrobial activity of Anacardium occidentale bark

Anacardium occidentale bark 60% methanolic extract exhibited antimicrobial activity against 13 out of 15 bacterial isolates at a concentration of 20 mg/ml.     

Antimicrobial activity of Pithecolobium avaremotemo bark

The Pithecolobium avaremotemo bark methanolic extract exhibited a broad spectrum and high levels of antimicrobial activity.     

Bioactive polar compounds from stem bark of Magnolia officinalis

Two new phenylethanoid glycosides magnoloside D (1) and E (2), together with nine known compounds, were isolated from the polar part of methanol extract of the stem bark of Magnolia officinalis. The structures of the new compounds were established on the basis of spectral analysis. Anti-spasmodic activity of four major constituents (3, 4, 9 and 11) was tested in isolated colon of rat, compounds 3, 4, and 9 showed inhibition against acetylcholine, with the effect similar to that of magnolol and honokiol. At the same time, antioxidant activity of the isolated compounds was investigated using a DPPH and an ORAC assay. All of the compounds, except compound 8 showed potent antioxidant capacity in the ORAC assay, while compounds 1-5 and 11 exhibited potent antioxidant activity in the DPPH assay.     

New ursane-type triterpenoid saponins from the stem bark of Schefflera heptaphylla

Phytochemical investigation on the stem bark of Schefflera heptaphylla led to the isolation of five new ursane-type triterpenoid saponins (1–5). Their structures were determined on the basis of spectroscopic and chemical methods. It is noteworthy in this study that the genins of all compounds are reported for the first time. All compounds isolated from this plant were evaluated for their inhibitory activities on lipopolysaccharide-induced nitric oxide production in RAW264.7 cells, and compounds 2 and 5 showed weak anti-inflammatory activities under their non-cytotoxic concentrations.     

Lanostane-type triterpenoid and steroid from the stem bark of Klainedoxa gabonensis

A new lanostane triterpenoid, 2-hydroxy-24-methylenelanostan-1,8-dien-3-one named klainedoxalanostenone (1) with one new steroid, 6-O-acyl-β-d-glucosyl-β-sitosterol named klainedoxasterol (2) together with ten known compounds including six triterpenoids (3–8), two steroids (9, 10) and two tanins (11, 12) were isolated from the stem bark of Klainedoxa gabonensis. To the best of our knowledge, this is the first report of lanostane-type triterpenoids from this genus. Their structures were determined by extensive analysis of spectroscopic data (1D and 2D NMR, MS) and by comparison with literature data. The xanthine oxidase inhibitory activity of nine compounds (1–6, 8, 10 and 11) were evaluated. Compound 5 showed a good xanthine oxidase inhibitory activity; the other tested compounds were moderately active.     

A new oleanane glycoside from the stem bark of Albizia gummifera

The stem bark of Albizia gummifera has yielded four triterpenes, lupeol, lupenone, vitalboside-A (1) and vitalboside-A 2'-methylglucuronate (2), the last of which appears to be novel.     

Four new sesquiterpene lactones from the stem bark of Illicium burmanicum

Four new sesquiterpene lactones (1), (2), (3), and (4), along with three known sesquiterene, namely, 6,7,10-trihydoxyisodaucane (5), 4β,10β-dihydroxyaromadendrane (6), and sescrassidiol (7) were isolated from the stem bark of Illicium burmanicum. The structures of the new compounds were determined using 1D and 2D NMR, and HRESIMS. The anti-inflammatory activities of these compounds were evaluated by measuring the enzymatic activity of luciferase in NF-κB reporters in a (Luc)-HEK 293 cell line treated with lipopolysaccharide (LPS).     

New cardenolides from the stem bark of Trewia nudiflora

Phytochemical investigation of the stem bark of Trewia nudiflora led to the isolation of two new cardenolides, trewianin (1) and trewioside (2), along with scopoletin (3) and indole-3-carboxylic acid (4). Structures were established by 1D- and 2D NMR spectroscopy, HR-MS analysis, and by comparison with literature data.     

A new phenolic glycoside from Sorocea ilicifolia stem bark

A new phenolic glycoside, 3,4-dimethoxyphenyl-1-O-beta-d-apiofuranosyl (1-->2)-beta-d-glucopyranoside (1), was isolated from the acetone extract of the Sorocea ilicifolia stem bark, along with the known compounds, 3,4,5-trimethoxyphenyl-1-O-beta-apiofuranosyl (1-->6)-beta-d-glucopyranoside, benzyl-O-beta-d-apiofuranosyl (1-->2)-beta-d-glucopyranoside, sorocein A, mulberrofuran K, kuwanon J, sorocein B, chalcomoracin, and kuwanol E.     

Antibacterial activity and cytotoxicity of extractives from Uvaria hamiltonii stem bark

The extracts as well as piperolactum C, goniopedaline, 6beta-hydroxystigmasta-4,22-dien-3-one and a mixture of cis- and trans-4-hydroxymelleins obtained from Uvaria hamiltonii stem bark exhibited mild to moderate in vitro antibacterial activity. The results obtained were compared with a standard antibiotic, kanamycin. In a brine shrimp lethality bioassay the pet-ether, dichloromethane, methanol extracts and a major alkaloid, piperolactum C were found to exhibit mild to moderate cytotoxicity.     

Antifungal activity of the stem bark of Ailanthus excelsa

The methanol extract of stem barks of Alianthus excelsa was partitioned with chloroform. The chloroform extract showed fungistatic and fungicidal activity against Aspergillus niger, A. fumigatus, Penicillium frequentence, P. notatum and Botrytis cinerea.     

Constituents of the stem bark of Ormosia wayana.

The isolation of lupeol, beta-sitosterol acetate and three quinolizidinic alkaloids, (+)-lupanine, (-)-sparteine and (-)-3 beta-hydroxy-13 alpha-tigloyloxy-lupanine (1), from the stem bark of Ormosia wayana is reported.