Morindaquinone, a new bianthraquinone from Morinda coreia roots.

Phytochemical investigation of the roots of Morinda coreia led to the isolation of one new bianthraquinone, morindaquinone (1), together with 12 known compounds, soranjidiol (2), rubiadin-1-methyl ether (3), 2-methoxy-1,3,6-trihydroxyanthraquinone (4), 1-hydroxy-2-methylanthraquinone (5), tectoquinone (6), nordamnacanthal (7), damnacanthal (8), 2-formylanthraquinone (9), 3-hydroxy-2-hydroxymethylanthraquinone (10), lucidin-ω-methyl ether (11), scopoletin (12) and (+)-mellein (13). The structures of these compounds were determined on the basis of extensive spectroscopic analyses, as well as by comparison with literature reports. Compound 1 was the first example of bianthraquinone found in the genus Morinda, whereas compound 13 was firstly isolated from this genus. Among them, compounds 2, 7, 8 and 10 exhibited moderate to weak cytotoxicity against human cervical (HeLa), human colon (HT 29) and human breast (MCF-7) cell lines, while compounds 6 and 9 - 11 showed weak anti-acetylcholinesterase activity.

A new pyrrole alkaloid from the roots of Cissampelos pareira.

Phytochemical investigation of the roots of Cissampelos pareira Linn. led to the isolation of one new pyrrole alkaloid, cissampeline (1), together with ten known alkaloids, (-)-curine (2), (-)-cyclanoline (3), (+)-tetrandrine (4), (+)-obaberine (5), (+)-obamegine (6), (-)-oblongine (7), (+)-homoaromoline (8), (-)-nor-N׳-chondrocurine (9), trans-N-feruloyltyramine (10) and (+)-coclaurine (11). Their structures were elucidated by extensive NMR and MS spectroscopic analyses. Interestingly, compound 1 represents the first example of pyrrole alkaloid found in the genus Cissampelos. Moreover, compounds 5-11 were isolated for the first time from this genus. Among them, compound 6 showed the highest anti-acetylcholinesterase activity with an IC50 value of 3.26 µM, whereas compound 8 displayed the most potent cytotoxicity against human colon cancer (HT29) cells with an IC50 value of 7.89 µM.

A new ent-abietane lactone from Glycosmis pentaphylla.

A new ent-abietane lactone, 3-oxojolkinolide A (1), together with 16 known compounds, helioscopinolide E (2), helioscopinolide A (3), 3-methyl-9H-carbazole (4), carbalexin (5), carbalexin B (6), glycaborinine (7), arborinine (8), 1H-indole-3-carbaldehyde (9), glycoamide A (10), glycoamide B (11), 2-(N-methyl-2-phenylacetamido)benzoic acid (12), 2-(methylamine)-methylbenzoate (13), fraxidin (14), scopoletin (15), (-)-syringaresinol (16) and ferulic acid (17) were isolated from Glycosmis pentaphylla. The structures of these compounds were elucidated using spectroscopic techniques such as NMR and MS. Among them, compounds 1-3, 9 and 12-17 were isolated from the genus Glycosmis for the first time.

A New Ajmaline-type Alkaloid from the Roots of Rauvolfia serpentina.

A new ajmaline-type alkaloid, 21-Ο-methylisoajmaline (1), together with twenty-one known compounds, a mixture of ß-sitosterol (2) and stigmasterol (3), reserpinine (4); tetrahydroalstonine (5), reserpine (6), venoterpine (7), yohimbine (8), 6'-O-(3,4,5-trimethoxybenzoyl)glomeratose A (9), isoajmaline (10), 3-epi-α-yohimbine (11), methyl 3,4,5-trimethoxy-trans-cinnamate (12), a mixture of ß-sitosterol 3-Ο-ß-D-glucopyranoside (13) and stigmasterol 3-Ο-ß-D- glucopyranoside (14), rescidine (15), 7-deoxyloganic acid (16), ajmaline (17), suaveoline (18), (+)-tetraphyllicine (19), loganic acid (20), 3-hydroxysarpagine (21), and sarpagine (22), were isolated from the roots of Rauvolla serpentina. Their structures were elucidated by spectroscopic data analysis and comparison with literature data. Compounds 11, 12 and 15 were for the first time identified from the genus Rauvolfla and 5, 7, 11, 12, 15, 18 and 22 were found from R. sepentina for the first time. Compound 11 showed moderate anticholinesterase activity with IC50 value of 15.58 µM, whereas 6 exhibited strong vasorelaxant activity with the EC50 value of 0.05 µM.

Abietane diterpenes from Hyptis suaveolens.

Investigation of the constituents of the whole plant of Hyptis suaveolens led to the isolation of three new abietane diterpenes, isosuaveolic acid (1), 8α,9α-epoxysuaveolic acid (2), and 14-O-methylsuaveolic acid (3), together with eleven known compounds. The structures of 1-3 were established by spectroscopic methods and chemical correlations. Some isolates were tested for their antimycobacterial and cytotoxic activities.

Fuscacarpans A-C, new pterocarpans from the stems of Erythrina fusca.

Chemical investigation of the stems of Erythrina fusca Lour. led to the isolation of three new pterocarpans, named fuscacarpans A-C (1-3), together with fourteen known compounds, sandwicensin (4), erythribyssin A (5), erythrabissin I (6), demethylmedicarpin (7), eryvarin D (8), erypoegin I (9), hydroxycristacarpone (10), orientanol A (11), scandenone (12), genistein (13), liquiritigenin (14), isoliquiritigenin (15), vestitone (16) and 3,7,4'-trihydroxyflavone (17). Structures 1-3 were elucidated by spectroscopic and chemical methods. The isolates were evaluated for antibacterial, antiplasmodial and cytotoxic activities.

Flavanoids and pterocarpans from the bark of Erythrina fusca.

Three new isomeric flavanones, fuscaflavanones A(1) (1), A(2) (2) and B (3), together with six known flavanones, lupinifolin (4), lonchocarpol A (5), a mixture of lonchocarpols C(1) and C(2) (6a, b), and a mixture of lonchocarpols D(1) and D(2) (7a, b), five pterocarpans, sandwicensin (8), phaseollidin (9), erythrabissin I (10), and a mixture of dolichins A and B (11a, b), one chalcone, isobavachalcone (12), and one isoflavone, wighteone (13), were isolated from the bark of Erythrina fusca LOUR. Their structures were elucidated on the basis of spectroscopic data. Some isolates were tested for antiplasmodial and cytotoxic activities and it was found that 5 and 9 exhibited moderate antiplasmodial activity against Plasmodium falciparum. For cytotoxicity, compounds 1, 4, 5, 9 and 12 showed moderate to weak activity against KB, BC and NCI-H187 cells, whereas 2 exhibited only weak activity against KB cells.

Erythrina alkaloids and a pterocarpan from the bark of Erythrina subumbrans.

Three new erythrina alkaloids, (+)-10,11-dioxoerythratine (1), (+)-10,11-dioxoepierythratidine (2), and (+)-10,11-dioxoerythratidinone (3), and a new pterocarpan, 1-methoxyerythrabyssin II (4), were isolated from the bark of Erythrina subumbrans, together with seven known pterocarpans, erythrabyssin II, erybraedin A, erystagallin A, erycristagallin, erythrabissin-1, eryvarin A, and hydroxycristacarpone, three flavanones, 5-hydroxysophoranone, abyssinone V, and lespedezaflavanone B, three triterpenes, sophoradiol, soyasapogenol B, and lupeol, and one isoflavanone, vogelin C. Their structures were elucidated on the basis of spectroscopic data. Some isolates were tested for antiplasmodial, antimycobacterial, and cytotoxic activities.

Biological activities of the chemical constituents of Erythrina stricta and Erythrina subumbrans.

Phytochemical investigation of the hexane and CH2Cl2 extracts of Erythrina stricta roots and E. subumbrans stems led to the isolation of six pterocarpans, one flavanone, one isoflavone, two alkaloids, five triterpenes, six steroids and alkyl trans-ferulates. The structures of all known compounds were determined on the basis of spectroscopic evidence. Sophoradiol (15), a mixture of stigmast-4-en-3-one (19) and stigmasta-4,22-dien-3-one (20), lupeol (21), cycloeucalenol (22), a mixture of 3beta-hydroxystigmast-5-en-7-one (23) and 3beta-hydroxystigmast-5,22-dien-7-one (24) and melilotigenin C (25) were first isolated from the genus Erythrina. The isolated compounds were evaluated for antiplasmodial activity, antimycobacterial activity and cytotoxicity. Among the tested compounds, 5-hydroxysophoranone (8) exhibited the highest antiplasmodial activity against Plasmodium falciparum (IC50 2.5 microg/mL). Compound 8, erystagallin A (5), erycristagallin (7) and erysubin F (10) showed the same level of antimycobacterial activity against Mycobacterium tuberculosis (MIC 12.5 microg/mL). For cytotoxicity, erybraedin A (2) showed the highest activity against the NCI-H187 and BC cells (IC50 2.1 and 2.9 microg/mL, respectively), whereas 10 exhibited the highest activity against the KB cells (IC50 4.5 microg/mL).

Antibacterial pterocarpans from Erythrina subumbrans.

Seven pterocarpans, erybraedin B (1), erybraedin A (2), phaseollin (3), erythrabyssin II (4), erystagallin A (5), erythrabissin-1 (6) and erycristagallin (7), two flavanones, 5-hydroxysophoranone (8) and glabrol (9), and one isoflavone, erysubin F (10), were isolated from the stems of Erythrina subumbrans (Leguminosae). Their structures were identified by means of spectroscopy. This is the first report of the isolation of the non-alkaloidal compounds from Erythrina subumbrans and the observed dehydration of 6a-hydroxypterocarpans 5 and 6 in CDCl(3) to the corresponding pterocarpenes 11 and 12, respectively. Compounds 8 and 9 were isolated for the first time from the genus Erythrina. Compounds 2 and 4 exhibited the highest degree of activity against Streptococcus strains with an MIC range of 0.78-1.56 microg/ml, whereas compound 7 exhibited the highest degree of activity against Staphylococcus strains, including drug-resistant strains (MRSA and VRSA), with an MIC range of 0.39-1.56 microg/ml. Interestingly, compounds 2, 4, 5 and 7 were more active against several strains of Streptococcus and Staphylococcus than the standard antibiotics vancomycin and oxacillin. Compound 7 showed the highest level of activity against all VRSA strains tested, with an MIC range of 0.39-1.56 microg/ml, which were resistant to both antibiotics. These compounds may prove to be potent phytochemical agents for antibacterial activity, especially against the MRSA and VRSA strains.

Chemical constituents and bioactivity of Piper sarmentosum.

Eight amides, pellitorine (1), guineensine (2), brachystamide B (3), sarmentine (4), brachyamide B (5), 1-piperettyl pyrrolidine (6), 3',4',5'-trimethoxycinnamoyl pyrrolidine (7) and sarmentosine (8), two lignans, (+)-asarinin (9) and sesamin (10), and four other compounds, 1-(3,4-methylenedioxyphenyl)-1E-tetradecene (11), methyl piperate (12) and a mixture of beta-sitosterol (13) and stigmasterol (14), were isolated from the fruits of Piper sarmentosum (Piperaceae). This is the first reported isolation of compounds 2, 3, 5, 6, 7, 9, 10 and 12 from this plant species. Their structures were established from spectral data. These compounds were evaluated in antituberculosis and antiplasmodial tests. The results showed that compounds 4 and 6 exhibited both activities while compounds 1, 2, 5, 8 and 11 showed only antituberculosis activity. This is the first report of the antituberculosis and antiplasmodial activities for these compounds.

(+)-Bornyl piperate, a new monoterpene ester from Piper aff. pedicellatum roots.

A new monoterpene ester, (+)-bornyl piperate was isolated from the underground roots of Piper aff. pedicellatum and its structure was elucidated on the basis of spectroscopic evidence and confirmed by X-ray analysis. The compound crystallizes in the triclinic space group P1 with a=7.3232(4) A, b=11.4705(7) A, c=23.2520(14) A, V=1943.6(2) A(3). This compound showed an antituberculosis activity against Mycobacterium tuberculosis (H(37)Ra strain) with the minimum inhibitor concentration (MIC) of 25 microg/ml.

Chabamide, a novel piperine dimer from stems of Piper chaba.

A novel piperine dimer, named chabamide, was isolated from stems of Piper chaba Hunter and its structure was elucidated on the basis of spectroscopic evidence. Chabamide showed antimalarial activity with an IC(50) value of 2.7 microg/ml and antituberculosis activity with the minimum inhibitory concentration (MIC) of 12.5 microg/ml.