Biochemical Systematics and Ecology

New Approach for the Construction of the Coumarin Frame and Application in the Total Synthesis of Natural Products

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One of the most promising plants in biological screening test results of thirteen Artocarpus species was Artocarpus obtusus FM Jarrett and detailed phytochemical investigation of powdered dried bark of the plant has led to the isolation and identification of three xanthones; pyranocycloartobiloxanthone A (1), dihydroartoindonesianin C (2) and pyranocycloartobiloxanthone B (3). These compounds were screened for antioxidant, antimicrobial and tyrosinase inhibitory activities. Pyranocycloartobiloxanthone A (1) exhibited a strong free radical scavenger towards DPPH free radicals with IC50 value of 2 µg/mL with prominent discoloration observed in comparison with standard ascorbic acid, α-tocopherol and quercetin, The compound also exhibited antibacterial activity against methicillin resistant Staphylococcus aureus (ATCC3359) and Bacillus subtilis (clinically isolated) with inhibition zone of 20 and 12 mm, respectively. However the other two xanthones were found to be inactive. For the tyrosinase inhibitory activity, again compound (1) displayed strong activity comparable with the standard kojic acid.

https://www.mdpi.com/1420-3049/17/5/6071/pdf

Antioxidant, Antimicrobial and Tyrosinase Inhibitory Activities of Xanthones Isolated from Artocarpus obtusus F.M. Jarrett

Isolation of new monoterpene coumarins from Micromelum minutum leaves and their cytotoxic activity against Leishmania major and cancer cells

A new 7-oxygenated coumarin, 7-demethylmurralonginol isovalerate (1), and a new natural product, murralonginol (2), together with seven known 7-oxygenated coumarins, murralonginol isovalerate (3), murralongin (4), micromelin (5), scopoletin (6), microminutin (7), murrangatin (8), and minumicrolin (9), were isolated from the fruits of Micromelum minutum. The structures of these compounds were established on the basis of their 1D and 2D NMR spectroscopic data. Among these isolates, compounds 2 and 4 - 9 exhibited cytotoxicity against cholangiocarcinoma cell line, KKU-100.

C-7 oxygenated coumarins from the fruits of Micromelum minutum.

The crude petroleum ether and chloroform extracts of Micromelum minutum (G. Frost.) Wright & Arn (Rutaceae) showed strong cytotoxic activity when tested against a T-lymphoblastic leukemia cell line. Further fractionation of the extracts resulted in the isolation of five new coumarins 3″,4″-dihydrocapnolactone, 2′,3′-epoxyisocapnolactone, 8-hydroxyisocapnolactone-29,39-diol, 8-hydroxy-3″,4″-dihydrocapnolactone-29,39-diol and 8,4″-dihydroxy-3″,4″-dihydrocapnolactone-29,39-diol, and two triterpenes. Some of these compounds were strongly active against T-lymphoblastic leukemia (CEM-SS), promyeolocytic leukemia (HL60), cervical cancer (HeLa) and liver cancer (HepG2) cell lines. 8-Hydroxyisocapnolactone-29,39-diol was found to be the most active with IC50 values of 2.9, 2.5, 6.9, and 5.9 μg/ml, respectively. This was followed by 2′,3′-epoxyisocapnolactone. When evaluated against the normal mouse fibroblast (3T3) cell line, 8-hydroxyisocapnolactone-29,39-diol was found to be inactive, hence it could serve as a v...

Cytotoxic activity of coumarins from Micromelum minutum

A new coumarin and triterpenes from Malaysian Micromelum minutum

The coumarin, 8-methoxycapnolactone and stigmasterol were isolated from the leaves of Micromelum minutum (Rutaceae) which collected from Sepilok, Sabah, Malaysia and their structures were characterized by spectroscopic methods. Key words: Micromelum minutum ; Coumarin; 8-Methoxycapnolactone, Stigmasterol

8-Methoxycapnolactone and stigmasterol From Micromelum minutum

The coumarin, 8-methoxycapnolactone and stigmasterol were isolated from the leaves of Micromelum minutum (Rutaceae) which collected from Sepilok, Sabah, Malaysia and their structures were characterized by

M. Aspollah Sukari

Papers

Cytotoxic activity of coumarins from Micromelum minutum

A new coumarin and triterpenes from Malaysian Micromelum minutum

8-Methoxycapnolactone and stigmasterol From Micromelum minutum

8-Methoxycapnolactone and stigmasterol From Micromelum minutum 8-Metoksikapnolakton dan stigmasterol dari Micromelum minutum