Unang Supratman

Triterpenes and steroids from the leaves of Aglaia exima (Meliaceae)

A study on the leaves of Aglaia exima led to the isolation of one new and seven known compounds: six triterpenoids and two steroids. Their structures were elucidated and analyzed mainly by using spectroscopic methods; 1D and 2D NMR, mass spectrometry, UV spectrometry and X-ray. All the triterpenoids and steroids were measured in vitro for their cytotoxic activities against eight cancer cell lines; lung (A549), prostate (DU-145), skin (SK-MEL-5), pancreatic (BxPC-3), liver (Hep G2), colon (HT-29), breast (MCF-7) and (MDA-MB-231). The new cycloartane triterpenoid, 24(E)-cycloart-24-ene-26-ol-3-one 1, showed potent cytotoxic activity against colon (HT-29) cancer cell line (IC(50) 11.5μM).

Cycloart-24-ene-26-ol-3-one, a New Cycloartane Isolated from Leaves of Aglaia exima Triggers Tumour Necrosis Factor-Receptor 1-Mediated Caspase-Dependent Apoptosis in Colon Cancer Cell Line.

Plants in the Meliaceae family are known to possess interesting biological activities, such as antimalaral, antihypertensive and antitumour activities. Previously, our group reported the plant-derived compound cycloart-24-ene-26-ol-3-one isolated from the hexane extracts of Aglaia exima leaves, which shows cytotoxicity towards various cancer cell lines, in particular, colon cancer cell lines. In this report, we further demonstrate that cycloart-24-ene-26-ol-3-one, from here forth known as cycloartane, reduces the viability of the colon cancer cell lines HT-29 and CaCO-2 in a dose- and time-dependent manner. Further elucidation of the compound’s mechanism showed that it binds to tumour necrosis factor-receptor 1 (TNF-R1) leading to the initiation of caspase-8 and, through the activation of Bid, in the activation of caspase-9. This activity causes a reduction in mitochondrial membrane potential (MMP) and the release of cytochrome-C. The activation of caspase-8 and -9 both act to commit the cancer cells to apoptosis through downstream caspase-3/7 activation, PARP cleavage and the lack of NFkB translocation into the nucleus. A molecular docking study showed that the cycloartane binds to the receptor through a hydrophobic interaction with cysteine-96 and hydrogen bonds with lysine-75 and -132. The results show that further development of the cycloartane as an anti-cancer drug is worthwhile.

Antifeedant Triterpenoids from the Seeds and Bark of Lansium domesticum cv Kokossan (Meliaceae)

Two tetranortriterpenoids, kokosanolide A (1) and C (2) were isolated from the seeds and three onoceranoid-type triterpenoids: kokosanolide B (3), 8,14-secogammacera-7,14-diene-3,21-dione (4) and a 1.5:0.5 mixture of 8,14-secogammacera-7,14(27)-diene-3,21-dione (5) and compound 4 were isolated from the bark of kokossan (Lansium domesticum). Complete 1H- and 13C-NMR data of the triterpenoids 1-5 are reported. The triterpenoids’ structures were elucidated primarily by means of high field 1D- and 2D-NMR, IR and HRMS spectral data. Triterpenoids 1-5 exhibited moderate to strong antifeedant activity against the fourth instar larvae of Epilachna vigintioctopunctata.

Kokosanolide from the seed of Lansium domesticum Corr.

In the title compound, [systematic name: 8,14-secogammacera-7,14(27)-diene-3,21-dione], C27H32O9, each of the six-membered rings adopts the common chair conformation. In the crystal, molecules are linked by an O–H⋯Oester hydrogen bond into a helical chain.

A phytotoxic bicyclic lactone and other compounds from endophyte Xylaria curta

Abstract A new compound, (3aS,6aR)-4,5-dimethyl-3,3a,6,6a-tetrahydro-2H-cyclopenta [b]furan-2-one (2), along with two known metabolites, myrotheciumone A (1) and 4-oxo-4H-pyron-3-acetic acid (3) was isolated from the ethyl acetate extract of fermentation broth of Xylaria curta 92092022. The structures of these compounds were elucidated on the basis of spectroscopic methods (UV, IR, HRESITOFMS, 1D NMR, and 2D NMR). Compounds 1 and 2 showed moderate antibacterial and phytotoxic activities.

14-Hy­droxy-8,14-secogammacera-7-ene-3,21-dione from the bark of Lansium domesticum Corr.

In the title compound (kokosanolide B), C30H48O3, the hexahydro- and octahydronaphthalen-2-one ring systems are connected through an ethylene fragment, with a C—CH2—CH2—C torsion angle of 176.2 (2)°. The cyclohexene ring adopts a half-chair conformation, while the other six-membered rings adopt distorted chair conformations. In the crystal, adjacent molecules are linked into a zigzag chain along the b axis by O—H⋯O hydrogen bonds involving the hydroxy and carbonyl groups.

(S)-2-Methyl-2-(4-methylpent-3-enyl)-6-(propan-2-ylidene)-3,4,6,7-tetrahydropyrano[4,3-g]chromen-9(2H)-one

A novel chromene, (S)-2-methyl-2-(4-methylpent-3-enyl)-6-(propan-2-ylidene)-3,4,6,7-tetrahydropyrano[4,3-g]chromen-9(2H)-one (1), was isolated from the leaves of Peperomia pellucida (Piperaceae). The chemical structure of 1 was determined by spectroscopic methods and comparison with those related compounds previously reported.

A new α-pyrone metabolite from a mangrove plant endophytic fungus, Fusarium sp.

A new α-pyrone derivative, compound 2, and a known one, cladobotrin V, were isolated from the culture broth of the mangrove endophyte Fusarium sp. IM-37. Their structures were determined spectroscopically and compared with previously reported spectral data. Compound 2 restored the growth inhibition caused by hyperactivated Ca2+-signaling in mutant yeast.

3-epi-Dammarenediol II 1.075 hydrate: a dammarane triterpene from the bark of Aglaia eximia.

The title dammarane tritepene, 3α,20(S)-dihydroxydammar-24-ene, which crystallized out in a hydrated form, C30H52O2.1.075H2O, was isolated from the Aglaia eximia bark. The three cyclohexane rings adopt chair conformations. The cyclopentane has an envelope conformation with the quaternary C at position 14 as the flap atom with the maximum deviation of 0.288 (2) Å. The methylheptene side chain is disordered over two positions with 0.505 (1):0.495 (1) site occupancies and is axially attached with an (+)-syn-clinal conformation. The hydroxyl group at position 3 of dammarane is in a different conformation to the corresponding hydroxyl in Dammarenediol II. In the crystal, the dammarane and water molecules are linked by ODammarane—H⋯Owater and Owater—H⋯ODammarane hydrogen bonds into a three-dimensional network.

Limonoids from the Seeds of Chisocheton macrophyllus

A new limonoid compound, dysobinol (1), along with three known limonoid compounds, 7α-hydroxyneotricilenone (2), dysobinin (3), and nimonol (4), was isolated from the seeds of Chisocheton macrophyllus (Meliaceae). Their structures were established by spectroscopic techniques such as UV, IR, MS, 1D, and 2D NMR. Compounds 1–4 showed cytotoxic activity against P-388 murine leukemia cells with IC50 values of 49.7, 79.4, 19.5, and 64.5 μg/mL, respectively.