Sarot Cheenpracha

Bioactive Carbazole Alkaloids from Clausena wallichii Roots

Four new carbazole alkaloids, clausenawallines C-F (1-4), along with 18 known compounds (5-22) were isolated from the roots of Clausena wallichii. Compounds 3, 9, and 22 exhibited significant antibacterial activity against methicillin-resistant Staphylococcus aureus SK1 (MRSA SK1) and Staph. aureus TISTR 1466 with MIC values in the range 4-16 μg/mL, whereas compound 4 showed the highest cytotoxicity against oral cavity cancer (KB) and small-cell lung cancer (NCI-H187) with IC(50) values of 10.2 and 4.5 μM, respectively.

Antibacterial carbazole alkaloids from Clausena harmandiana twigs.

Three new carbazole alkaloids, harmandianamines A-C (1-3), together with fifteen known compounds (4-18) were isolated from the twigs of Clausena harmandiana. The structures were elucidated by spectroscopic methods, including UV, IR, NMR, and MS. The antibacterial activity against Escherichia coli TISTR 780, Salmonella typhimurium TISTR 292, Staphylococcus aureus TISTR 1466 and methicillin-resistant S. aureus (MRSA) SK1 of some isolated compounds was also evaluated. Compound 6 exhibited significant antibacterial activity against MRSA SK1 with an MIC value of 0.25 μg/mL which higher than that of standard drug, vancomycin (MIC value=1 μg/mL) whereas compounds 14 and 5 showed strong activity with MIC values of 4 and 8 μg/mL, respectively. Only compound 14 showed strong antibacterial activity against S. aureus TISTR 1466 with an MIC value of 4 μg/mL.

Candenatenins A−F, Phenolic Compounds from the Heartwood of Dalbergia candenatensis

Chemical investigation of the CH2Cl2 extract of the heartwood of Dalbergia candenatensis affored six new phenolic compounds, designated candenatenins A-F (1-6), as well as four known compounds, (2R,3R)-3,5-dihydroxy-7-methoxyflavanone (7), 4-hydroxy-3-methoxy-8,9-methylenedioxypterocarpan (8), nutiducol (9), and sophoraflavanone A (10). The structures of the new compounds were determined by 1D- and 2D-NMR spectroscopic studies as well as by MS analysis. The cytotoxic activities of the isolated compounds are also reported.

Coumabiocins A−F, Aminocoumarins from an Organic Extract of Streptomyces sp. L-4-4

Bioassay-directed fractionation of the butanol extract of Streptomyces sp. L-4-4, using the hyphae formation inhibition assay of a prokaryotic whole cell, led to the isolation of six new aminocoumarins, coumabiocins A-F (1-6), along with two known compounds, novobiocin (7) and isonovobiocin (8). Coumabiocins A-E (1-5) contain three structural elements, a central 3-amino-7-hydroxycoumarin that is linked at the 3-amino group to a prenylated 4-hydroxybenzoic acid moiety and at the 7-position to an l-noviosyl sugar, while coumabiocin F (6) lacks the sugar moiety. Their structures were elucidated by spectroscopic methods including 1D- and 2D-NMR techniques and mass spectrometric analyses. Coumabiocins A-E (1-5) exhibited significant inhibitory activity against Streptomyces 85E and gave a 10-15 mm clear zone of inhibition at 20 microg/disk and a 10 mm bald and a 10 mm clear zone of inhibition at 5 and 10 microg/disk, respectively, whereas coumabiocin F (6) was inactive.

Alstoniaphyllines A-C, unusual nitrogenous derivatives from the bark of Alstonia macrophylla

Chemical investigation of an alkaloidal extract of Alstonia macrophylla bark led to the isolation and identification of two new nitrogenous derivatives, alstoniaphyllines A (1) and B (2), a new indole alkaloid, alstoniaphylline C (4), and eight known alkaloids (3, 5-11). Alstonisine (9) exhibited antiplasmodial activity against Plasmodium falciparum, with an IC50 of 7.6 μM.

Clausenawallines G-K, carbazole alkaloids from Clausena wallichii twigs

Five carbazole alkaloids, clausenawallines G-K (1-5), along with 12 known alkaloids (6-17) were isolated from the twigs of Clausena wallichii. Their structures were established using spectroscopic methods and the antibacterial activity of compounds 1-5 was evaluated.

Cowabenzophenones A and B, two new tetracyclo[7.3.3.33,11.03,7]tetradecane-2,12,14-trione derivatives, from ripe fruits of Garcinia cowa

Two new tetracyclo[7.3.3.3(3,11).0(3,7)]tetradecane-2,12,14-trione derivatives, cowabenzophenones A (1) and B (2), were isolated from ripe fruits of Garcinia cowa Roxb. Their structures were determined by spectroscopic methods. The tetracyclo[7.3.3.3(3,11).0(3,7)]tetradecane-2,12,14-trione skeleton from the Garcinia genus is reported for the first time.

Chemical constituents from the roots of Feroniella lucida

A new furanocoumarin named lucidafuranocoumarin A (7) together with 13 known coumarins (1–6, 8–14) and four known alkaloids (15–18) was isolated from the roots of Feroniella lucida. Their structures were elucidated on the basis of spectroscopic analysis. Some of the isolates were evaluated for their biological activities, and compound 18 showed strong cytotoxicity against KB (IC50 = 0.637 μg/ml) and NCI-H187 (IC50 = 0.094 μg/ml) human cancer cell lines, antimalarial activity against Plasmodium falciparum (IC50 = 0.336 μg/ml), and antituberculosis activity against Mycobacterium tuberculosis (MIC = 6.25 μg/ml).

Antimalarial Oxoprotoberberine Alkaloids from the Leaves of Miliusa cuneata

Five new oxoprotoberberine alkaloids, miliusacunines A-E (1-5), along with nine known compounds, 6-14, were isolated from an acetone extract of the leaves and twigs of Miliusa cuneata. Their structures were elucidated by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicities against the KB and Vero cell lines and for antimalarial activities against the Plasmodium falciparum strains TM4 and K1 (a sensitive and a multi-drug-resistant strain, respectively). Compound 1 showed in vitro antimalarial activity against the TM4 strain, with an IC50 value of 19.3 ± 3.4 μM, and compound 2 demonstrated significant activity against the K1 strain, with an IC50 value of 10.8 ± 4.1 μM. Both compounds showed no discernible cytotoxicity to the Vero cell line at the concentration levels evaluated.

Cytotoxic Carbazole Alkaloids from the Stems of Murraya koenigii

Murraya koenigii is a tropical to subtropical small tree belonging to the Rutaceae family. The plant is native to India and is distributed in most of Southern Asia. The leaves of this plant are highly aromatic, and young leaves are used as a vegetable herb in the Southern part of Thailand. Various parts of the plant have been reported as a folk medicine. The leaves, stems, and roots are used externally in skin eruptions and bites of venomous animals, while the barks and roots are used as a stimulant [1]. Previous phytochemical investigations led to the isolation of a number of carbazole alkaloids, some of which have been indicated for their antioxidant, antitumor, antimicrobial, antiinflammatory, antitrypanocidal, and mosquitocidal activities [2–5]. In the course of our ongoing search for bioactive compounds from Rutaceae medicinal plants, we found that the EtOAc extract of the stems of M. koenigii exhibited cytotoxicity against three human cancer cell lines, including oral cavity cancer (KB), breast cancer (MCF7), and small cell lung cancer (NCI-H187). In this paper, we describe the isolation and cytotoxic activity of the crude extract and pure carbazole alkaloids from the stems of M. koenigii. The EtOAc extract of M. koenigii stems showed cytotoxic activity against KB, MCF7, and NCI-H187 cancer cell lines, with IC50 values of 35.54, 17.56, and 14.86 g/mL, respectively. The activity-guided investigation of this extract resulted in the identification of nine earlier isolated carbazole alkaloids from M. koenigii, including murrayanine (1) [6], koenoline (2) [7], mahanimbinol (3) [8], girinimbine (4) [9], mahanimbine (5) [9], furostifoline (6) [10], murrayazoline (7) [9], murrayaquinone A (8) [9], and murrayazolidine (9) [11]. Compound 6 was isolated for the first time from M. koenigii. All structures were characterized by spectroscopic methods and comparison of their physical and spectral data with reported values. Murrayanine (1). Yellow solid, mp 158–161 C. 1H NMR (400 MHz, CDCl3, , ppm, J/Hz): 10.04 (1H, s, CHO), 8.69 (1H, br.s, NH), 8.18 (1H, br.s, H-2), 8.10 (1H, d, J = 8.0, H-5), 7.51 (1H, m, H-8), 7.49 (1H, m, H-7), 7.45 (1H, br.s, H-2), 7.31 (1H, m, H-6), 4.06 (3H, s, OCH3). 13C NMR (100 MHz, CDCl3, , ppm): 191.8 (CHO), 146.0 (C-1), 139.4 (C-8a), 134.0 (C-8b), 130.1 (C-3), 126.6 (C-7), 123.6 (C-4a and C-4b), 120.7 (C-5 and C-6), 120.4 (C-4), 111.5 (C-8), 103.5 (C-2), 55.8 (OCH3). Koenoline (2). Brown viscous oil. 1H NMR (400 MHz, CDCl3, , ppm, J/Hz): 8.28 (1H, br.s, NH), 8.03 (1H, d, J = 8.0, H-5), 7.65 (1H, br.s, H-4), 7.46 (1H, br.d, J = 8.0, H-8), 7.41 (1H, m, H-7), 7.22 (1H, m, H-6), 6.95 (1H, br.s, H-2), 4.80 (2H, s, H-1 ), 4.01 (3H, s, OCH3), 2.17 (1H, br.s, OH). 13C NMR (100 MHz, CDCl3, , ppm): 145.7 (C-1), 139.2 (C-8a), 132.7 (C-3), 129.1 (C-8b), 125.8 (C-7), 125.7 (C-4a), 124.0 (C-4b), 120.5 (C-5), 119.5 (C-6), 111.7 (C-4), 111.0 (C-8), 105.6 (C-2), 66.5 (C-1 ), 55.5 (OCH3). Mahanimbinol (3). Brown viscous oil. 1H NMR (400 MHz, CDCl3, , ppm, J/Hz): 7.93 (1H, br.d, J = 7.6, H-5), 7.85 (1H, br.s, NH), 7.68 (1H, s, H-4), 7.36 (1H, br.d, J = 8.0, H-8), 7.30 (1H, br.t, J = 7.6, 7.2, H-6), 7.17 (1H, br.t, J = 7.2, H-7), 5.37 (1H, t, J = 6.8, H-2 ), 5.21 (1H, br.s, OH), 5.07 (1H, m, H-6 ), 3.62 (2H, d, J = 6.8, H-1 ), 2.40 (3H, s, CH3-3), 2.12 (4H, m, H-4 and -5 ), 1.90 (3H, s, CH3-9 ), 1.66 (3H, s, CH3-8 ), 1.59 (3H, s, CH3-10 ). 13C NMR (100 MHz, CDCl3, , ppm): 151.2 (C-2), 139.4 (C-8a), 139.0 (C-3 ), 138.4 (C-8b), 132.1 (C-7 ), 124.2 (C-6), 123.6 (C-4b and C-6 ), 121.3 (C-2 ), 119.3 (C-4, C-5 and C-7), 117.0 (C-3), 116.6 (C-4a), 110.3 (C-8), 107.8 (C-1), 39.6 (C-4 ), 26.4 (C-5 ), 25.6 (CH3-8 ), 24.7 (C-1 ), 17.7 (CH3-10 ), 16.5 (CH3-3), 16.4 (CH3-9 ).