Antimycobacterial and antiplasmodial unsaturated carboxylic acid from the twigs of Scleropyrum wallichianum

From the twigs of Scleropyrum wallichianum, a new unsaturated carboxylic acid, scleropyric acid (1), two new esters, beta-sitosteryl-3-O-scleropyrate (2) and stigmasteryl-3-O-scleropyrate (3), and two well-known sterols, beta-sitosterol (4) and stigmasterol (5), were isolated and characterized using spectroscopic methods. Compound 1 exhibited antimycobacterial activity with an MIC value of 25 microg/ml and showed antiplasmodial activity with an IC50 value of 7.2 microg/ml. Compounds 2 and 3 were inactive in both assays.     

Chemical constituents and biological activities from branches of Colubrina asiatica

Sixteen compounds were isolated from a Thai medicinal plant, Colubrina asiatica. The isolated compounds were elucidated on the basis of spectroscopic methods (IR, 1D and 2D NMR) as six triterpene acids (1–6), five steroids (7–11), one benzoic acid derivative (12), two peptides (13 and 14), one sesquiterpenoid (15) and one jujubogenin (16). Compounds 3 and 10 showed antimalarial activity against Plasmodium falciparum. Compound 5 showed antimycobacterial activity. Moreover, compounds 3, 5, 6, 10 and 14 exhibited weak cytotoxicity against cancer cell lines. Compounds 1–15 have been isolated for the first time from this plant.     

Synthesis of alkaloid-like compounds via the bridging Ritter reaction

Abstract  

Alkaloid-like compounds containing a benzo[c]azepine core structure were successfully prepared in three steps from 5H-dibenzo[a,d]cyclohepten-5-ol via the bridging Ritter reaction. Biological studies of these compounds revealed that some of them are AChE inhibitors and antimalarial agents.     

A new coruleoellagic acid derivative from stems of Rhodamnia dumetorum

A new coruleoellagic acid derivative, 3,3′,4,4′,5′-pentamethylcoruleoellagic acid (1) together with nine known compounds, hexamethylcoruleoellagic acid (2), 3,4,3′-tri-O-methylellagic acid (3), heptaphylline (4), 7-methoxymukonal (5), dentatin (6), sinapaldehyde (7), gallic acid (8), 2,6-dimethoxy-4H-pyran-4-one (9) and β-sitosterol (10) were isolated from the stems of Rhodamnia dumetorum. Their structures were identified by physical and spectroscopic data (IR, 1D and 2D NMR, and MS). Compounds 1, 2 and 7-10 were tested for antibacterial activity against six pathogenic bacterial strains (Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Methicillin resistant S. aureus (MRSA)).     

Two new bioactive triterpenoids from the roots of Colubrina asiatica

Abstract

Two new ceanothane triterpenes, 3,7-O,O-dibenzoyl ceanothic acid methylester (1) and 3-O-acetyl-7-O-benzoyl ceanothic acid methylester (2), along with nine known compounds (3–11), were isolated from the roots of Colubrina asiatica. The isolated compounds were identified by spectroscopic evidence. Compounds 1 and 2 showed antimalarial activity against Plasmodium falciparum with IC₅₀ values of 4.67 and 3.07?µg/mL, respectively. Compound 2 also showed antimycobacterial activity against Mycobacterium tuberculosis (MIC 6.25?µg/mL). In addition, compounds 1, 2, 10 and 11 showed cytotoxicity against three cancer cell lines (KB, NCI-H187 and MCF-7) with IC₅₀ values ranging from 8.32 to 46.72?µg/mL.     

Bioactive meroterpenoids and alkaloids from the fungus Eurotium chevalieri

Five new meroterpenoids, chevalones A-D (1-4), aszonapyrone B (8), and a new sequiterpene alkaloid, eurochevalierine (5), together with four known compounds, sequiterpene (6), terpenoid pyrrolobenzoxazine named CJ-12662 (7), meroterpenoid, aszonapyrone A (9), and ergosterol were isolated from the fungus Eurotium chevalieri. The structures were established on the basis of spectroscopic evidence. The configurations of 1 and 5 were determined by X-ray analysis. The biosynthetic pathway of 1-3, 8, and 9 were proposed. Chemical transformation of aszonapyrone A (9) was also studied. Compounds 4, 5, and 7 exhibited antimalarial activity against Plasmodium falciparum, while 3, 5, and 7 showed antimycobacterial activity against Mycobacterium tuberculosis. In addition, compounds 2-7 showed cytotoxicity against cancer cell lines.     

Cytotoxic sesquiterpenes from luminescent mushroom Neonothopanus nambi

Four new aristolane sesquiterpenes named nambinones A–C (1–3) and 1-epi-nambinone B (4), a new sesquiterpene, nambinone D (5), a known compound, aurisin A (6) as well as a new dimeric sesquiterpene, aurisin K (7), were isolated from two isolates of luminescent mushroom, Neonothopanus nambi, PW1 and PW2. These structures were established on the basis of spectroscopic evidence. The relative configuration of 6 was determined by X-ray crystallographic analysis. Compounds 6 and 7 exhibited antimalarial activity against Plasmodium falciparum and antimycobacterial activity against Mycobacterium tuberculosis. Compounds 3, 6, and 7 showed cytotoxicity against NCI-H187 cancer cell lines. In addition, 6 and 7 showed cytotoxicity against the cholangiocarcinoma cell lines.     

A new coumarin from the roots of Micromelum minutum

A new coumarin, minutuminolate (1), together with eleven known coumarins (2–12), was isolated from the roots of Micromelum minutum. The structures of these compounds were established on the basis of their 1D and 2D NMR spectroscopic data. Compounds 2, 5, 10, 11 and 12 showed cytotoxicity against KB cell line. In addition, compounds 2, 3, 4, 7, 11 and 12 also showed weak cytotoxicity against NCI-H187 cell line.