Cytotoxic ent-kaurane diterpenoids from Isodon eriocalyx.

Five new ent-kaurane diterpenoids, epi-maoecrystal N (1), eriocalyxin G (2), maoecrystal W (3), maoecrystal X (4), and maoecrystal Y (5), along with 22 known ones, were isolated from Isodon eriocalyx (Dunn.) Hara., and their structures were determined by spectroscopic methods. All diterpenoids, except for 3 and 13, were evaluated for inhibition of the K562, T-24, Me180, QGY-7701, and BIU87 cell lines (Table 2).

Diterpenoids from Isodon enanderianus.

Four ent-kauranoids, 6-epiangustifolin and enanderinanins F-H, as well as 11 known ent-kaurane diterpenoids, macrocalin B, xerophilusin A, trichorabdal A, trichorabdal B, effusin, angustifolin, longikaurin D, longikaurin F, enanderinanin B, xerophilusin G and shikokianin were isolated from the aerial parts of Isodon enanderianus. The new diterpenoids were identified as 6-epiangustifolin (11alpha-hydroxy-6alpha-methoxy-6,19-epoxy-6,7-seco-ent-kaur-16-en-15-one-7,20-olide), enanderinanin F (19-acetoxy-6,20:6,11beta-diepoxy-6,7-seco-ent-kaur-16-en-15-one-1beta,7-olide), enanderinanin G (1beta,6beta,7beta-trihydroxy-19-acetoxy-16beta-methoxymethyl-7alpha,20-epoxy-ent-kaur-15-one) and enanderinanin H (6beta,7beta,14beta-trihydroxy-1alpha,11beta-acetonide-7alpha,20-epoxy-ent-kaur-16-en-15-one), respectively, on the basis of spectral data, especially by 2D NMR techniques. 6-Epiangustifolin showed significant cytotoxic activity against K562 cell.

ent-Labdane diterpenoids from Andrographis paniculata.

Six new ent-labdane diterpenoids, 3-O-beta-D-glucopyranosyl-14,19-dideoxyandrographolide (1), 14-deoxy-17-hydroxyandrographolide (2), 19-O-[beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoyl]-3,14-dideoxyandrographolide (3), 3-O-beta-d-glucopyranosylandrographolide (4), 12S-hydroxyandrographolide (5), and andrographatoside (6), together with 17 known analogues, were isolated from the aerial parts of Andrographis paniculata. The structures of 1-6 were determined by spectroscopic data analysis. All compounds isolated were evaluated for their inhibitory activity against several bacterial and fungal strains.

Lancifodilactones B-E, new nortriterpenes from Schisandra lancifolia.

Four new nortriterpenes, lancifodilactones B-E (1-4), were isolated from the leaves and stems of Schisandra lancifolia. Their structures were determined by analysis of 1D and 2D NMR spectroscopic data. These compounds are members of a new highly oxygenated cycloartane skeletal class with a biosynthetically modified eight-membered ring D.

Cytotoxic ent-kauranoids from Isodon leucophyllus.

Two new compounds, baiyecrystals D and E (1, 2), together with eight known analogues, xerophilusin B (4), macrocalin B (5), oridonin (6), rosthorin A (7), lasiocarpanin (8), rabdoternin A (9) and phyllostachysin A (10) and B (11), were isolated from the aerial parts of Isodon leucophyllus. The structures of 1 and 2 and 4-11 were elucidated on the basis of spectroscopic methods, especially the 2D NMR spectral analysis. Compounds 2, 6-8 and 10 were evaluated for their antineoplastic activities in vitro. Among them, lasiocarpanin (8) showed significant inhibitory activities against K562 and Bcap37 cells, with the IC50 values of 0.13 and 1.26 microg mL(-1), respectively, which were lower than those of the positive control.

Ent-kaurane diterpenoids from Isodon rubescens var. lushanensis.

Four new ent-kaurane diterpenoids lushanrubescensins F-I (1-4), together with 11 known ones, lasiodonin (5), oridonin (6), ponicidin (7), isodonoiol (8), isodonal (9), rabdosin B (10), rabdoternins A and B (11 and 12), enmenol (13), epinodosin (14), and inflexusin (15), were isolated from Isodon rubescens var. lushanensis, and the structures were elucidated by spectroscopic analysis. The inhibitory effect against the K562, Bcap37, BGC823, BIU87, CA, CNE, and Hela cell lines of compounds 3 and 5-10 were evaluated.

Triterpene saponins from Craniotome furcata.

Three saponins, craniosaponin A (1) and buddlejasaponins Ia (2) and I (3) were isolated from the n-butanol soluble fraction of Craniotome furcata for the first time. Among them, craniosaponin A (1) was identified to be a new compound. The structure of craniosaponin A was assigned mainly by spectral methods. A preliminary assay in vitro was applied to evaluate their cytotoxicity against several tumor cell-lines.

Cytotoxic ent-kaurane diterpenoids from Isodon sculponeata.

Four new ent-kaurane diterpenoids, sculponeatins F-I (1-4), together with six known compounds, sculponeatin E (5), epi-nodosin (6), epi-nodosinol (7), enmein (8), and macrocalyxoformins A and B (9 and 10), were isolated from the leaves of Isodon sculponeata. Also obtained were ursolic acid, 2alpha,3beta-dihydroxy-urs-12-en-28-oic acid, 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-oic acid, beta-sitosterol, daucosterol, quercetin, pedalitin, rosmarinic acid, caffeic acid and ethyl caffeic acid. Their structures were determined by spectral methods (1D-, 2D-NMR and MS). Some diterpenoids were tested for their cytotoxicity to inhibit three kinds of human tumor cells K562, A549 and T24. Compounds 3, 4, 6, 8, and 10 showed significant inhibitory effect toward K562 with IC(50) values ranging from 3.2 microg/ml to 8.2 microg/ml, while 3 and 6 exhibited potent antitumor activity against T24, but none exhibited cytotoxicity toward the cells of A549.

Cytotoxic 3,20-epoxy-ent-kaurane diterpenoids from Isodon eriocalyx var. laxiflora.

Four new ent-kaurane diterpenoids, laxiflorins J-M (1-4), along with maoecrystal A (5) and maoecrystal P (6), were isolated from the leaves of Isodon eriocalyx var. laxiflora. Their structures were determined by spectroscopic analyses. All the compounds were assayed for their cytotoxic effects on human tumor K562, A549, and T24 cell lines. Compounds 1 and 6 showed significant inhibitory effects on human tumor K562 and T24 cells, with IC(50) values less than 0.5 microg/mL. Compound 3 also demonstrated cytotoxic activities against all three types of human tumor cells, with IC(50) values in the range of 1-25 microg/mL.

Abietane diterpenoids from Coleus xanthanthus.

Eight new abietane diterpenoids, coleon U 11-acetate (1), 16-acetoxycoleon U 11-acetate (2), and xanthanthusins F-K (3-8), together with five known analogues, coleon U (9), 16-O-acetylcoleon C (10), coleon U-quinone (11), 8alpha,9alpha-epoxycoleon U-quinone (12), and xanthanthusin E (13), were isolated from the aerial parts of Coleus xanthanthus. The structures of 1-8 were elucidated on the basis of spectral methods. Compounds 1, 5, and 11-13 were evaluated for their cytotoxicity against K562 human leukemia cells.

Cytotoxic ent-kaurane diterpenoids from Isodon eriocalyx var. laxiflora.

Three new ent-kaurane diterpenoids laxiflorin E (1), laxiflorin H (6) and laxiflorin I (8) were isolated from the leaves of Isodon eriocalyx var. laxiflora, along with nine known diterpenoids, eriocalyxin A (2), laxiflorin C (3), laxiflorin D (4), laxiflorin A (5), maoecrystal S (7), maoecrystal Q (9), eriocalyxin B (10), maoecrystal C (11) and enmelol (12). The structures of the new compounds were determined by spectroscopic methods. Compounds 1-5 are 6,7-seco-ent-kaurane-7,20-olide diterpenoids, and 6-12 belong to 7,20-epoxy-ent-kauranoids. The spectral data of enmelol (12) are reported here for the first time. Ten of these compounds were tested for their cytotoxicity toward K562 and T24 human tumor cells. Compounds 1, 3 and 10 showed significant inhibitory effects on K562 cells with IC50 values 0.077, 0.569 and 0.373 microg/mL, and compounds 1 and 10 also demonstrated significant inhibitory activities toward T24 cells with IC50 values 0.709 and 0.087 microg/mL. Compounds 8 and 11 also displayed inhibitory effect on both two kinds of cells with IC 50 value less than 6.5 microg/mL.