Eudesmanolides and Other Constituents from the Flowers of Wedelia trilobata

Two eudesmane sesquiterpene lactones, wedetrilides B ( 1 ) and C ( 2 ), along with five known analogues ( 3 – 8 ), an ent‐kaurane diterpenoid ( 9 ), a steroid ( 10 ), as well as cinnamic acid derivatives ( 11 – 13 ), were isolated from the flowers of Wedelia trilobata. Their structures were elucidated on the basis of extensive spectroscopic analyses and by comparison of their NMR data with those of related compounds. Furthermore, the structures of 1 and 3 – 5 were confirmed by X‐ray single‐crystal diffraction analyses. Compounds 4 and 5 exhibited weak cytotoxic activities against the MCF‐7, HeLa, and A549 cell lines. Compounds 3 – 5 were also evaluated for their inhibitory effects against HIV lytic replication.     

Synthesis of Lanostane‐Type Triterpenoid N‐Glycosides and Their Cytotoxicity against Human Cancer Cell Lines

Seventeen lanostane‐type triterpenoid derivatives ( 2 – 18 ), including 11N‐glycosides ( 8 – 18 ), were synthesized from the natural triterpenoid, lanosterol ( 1 ), and were evaluated for their cytotoxicity against the human cancer cell lines, HL‐60, A549, and MKN45, as well as the normal human lung cells, WI‐38. Among them, N‐β‐d ‐2‐acetamido‐2‐deoxyglucoside ( 10 ) showed cytotoxicity against HL‐60, A549, MKN45, and WI‐38 cells (IC₅₀ 0.0078 – 2.8 μm ). However, N‐β‐d ‐galactoside ( 12 ) showed cytotoxicity against HL‐60 and MKN45 cells (IC₅₀ 0.0021 – 4.0 μm ), but not the normal WI‐38 cells. Furthermore, Western blot analysis suggested that 12 induces apoptosis by activation of caspases‐3, 8, and 9. These results will be useful for the synthesis of other tetracyclic triterpenoids or steroid N‐glycosides to increase their cytotoxicity and apoptosis‐inducing activities.     

A New Cytotoxic Carbazole Alkaloid and Two New Other Alkaloids from Clausena excavata

One new carbazole alkaloid, excavatine A ( 1 ), and two additional new alkaloids, excavatine B ( 2 ) and excavatine C ( 3 ), were isolated from the stems and leaves of Clausena excavata Burm .f. (Rutaceae). Their structures were determined on the basis of detailed spectroscopic analyses, especially 2D‐NMR and HR‐EI‐MS data. Compounds 1 – 3 were tested for their cytotoxic activities against A549, HeLa, and BGC‐823 cancer cell lines, and for their antimicrobial activities against Candida albicans and Staphylococcus aureus. Only 1 exhibited cytotoxicity against A549 and HeLa cell lines with the IC₅₀ values of 5.25 and 1.91 μg/ml, respectively.     

Melanogenesis‐Inhibitory and Cytotoxic Activities of Chemical Constituents from the Leaves of Sauropus androgynus L. Merr. (Euphorbiaceae)

A new steroid, 20‐hydroxyisofucosterol (stigmasta‐5,24(28)‐diene‐3β,20β‐diol) ( 7 ), along with six known compounds 1 – 6 were isolated from the MeOH extract of the leaves of Sauropus androgynus L. Merr . (Euphorbiaceae). The structure of new steroid was determined by HR‐APCI‐MS and various NMR techniques in combination with literature data. Subsequently, their anti‐inflammatory, cytotoxic activities against five human cell lines, as well as inhibitory activities against the α‐MSH induced melanogenesis on the B16 cell line were evaluated. As the results, steroid compounds, 6 and 7 exhibited moderate cytotoxic to HL60, AZ521, SKBR3, and A549 tumor cell lines (IC₅₀ 26.9 – 45.1 μm ) with high tumor selectivity for A549 relative to WI38 cell lines (SI 2.6 and 3.0, resp.). And, flavonoid compounds, 4 and 5 exhibited superior inhibitory activities against melanogenesis (67.0 – 94.7% melanin content), even with no or low toxicity to the cells (90.1 – 99.6% cell viability) at the concentrations from 10 to 100 μm . Furthermore, Western blot analysis suggested that compound 5 could inhibit melanogenesis by suppressing the protein expressions of MITF, TRP‐1, TRP‐2, and tyrosinase.     

Triterpenoid Alkaloids from Buxus microphylla

Two new triterpenoid alkaloids, buxmicrophyllines J and K ( 1 and 2 , resp.), together with four analogues, 3 – 6 , were isolated from the leaves and stems of Buxus microphylla. The structures of the new compounds were elucidated by NMR and MS spectroscopic analyses. The partial assignments of the NMR spectra of 3 were also revised. Compounds 1 and 3 – 6 were evaluated for their growth inhibitory activity against human cell lines HL‐60, SMMC‐7721, A‐549, SK‐BR‐3, and PANC‐1. Compound 6 showed significant cytotoxicity against HL‐60, SK‐BR‐3, and PANC‐1 cell lines, with IC₅₀ values of 6.46, 19.61, and 28.57 μM , respectively.     

Cytotoxic and Nitric Oxide Production‐Inhibitory Activities of Limonoids and Other Compounds from the Leaves and Bark of Melia azedarach

Nine limonoids, 1 – 9 , one apocarotenoid, 11 , one alkaloid, 12 , and one steroid, 13 , from the leaf extract; and one triterpenoid, 10 , five steroids, 14 – 18 , and two flavonoids, 19 and 20 , from the bark extract of Melia azedarach L. (Chinaberry tree; Meliaceae) were isolated. Among these compounds, three compounds, 4 – 6 , were new, and their structures were established as 3‐deacetyl‐28‐oxosalannolactone, 3‐deacetyl‐28‐oxosalanninolide, and 3‐deacetyl‐17‐defurano‐17,28‐dioxosalannin, respectively, on the basis of extensive spectroscopic analyses and comparison with literature data. All of the isolated compounds were evaluated for their cytotoxic activities against leukemia (HL60), lung (A549), stomach (AZ521), and breast (SK‐BR‐3) cancer cell lines. 3‐Deacetyl‐4′‐demethyl‐28‐oxosalannin ( 3 ) against HL60 and AZ521 cells, and methyl kulonate ( 10 ) against HL60 cells exhibited potent cytotoxicities with IC₅₀ values in the range of 2.8–5.8 μM . In addition, upon evaluation of compounds 1 – 13 against production of nitric oxide (NO) in mouse macrophage RAW 264.7 cells induced by lipopolysaccharide (LPS), seven, i.e., trichilinin B ( 1 ), 4 , ohchinin ( 7 ), 23‐hydroxyohchininolide ( 8 ), 21‐hydroxyisoohchininolide ( 9 ), 10 , and methyl indole 3‐carboxylate ( 12 ), inhibited production of NO with IC₅₀ values in the range of 4.6–87.3 μM with no, or almost no, toxicity to the cells (IC₅₀ 93.2–100 μM ). Western blot analysis revealed that compound 7 reduced the expression levels of the inducible NO synthase (iNOS) and COX‐2 proteins in a concentration‐dependent manner. Furthermore, compounds 5, 6, 13 , and 18 – 20 exhibited potent inhibitory effects (IC₅₀ 299–381 molar ratio/32 pmol TPA) against Epstein? Barr virus early antigen (EBV‐EA) activation induced by 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) in Raji cell line.     

Three New and Other Limonoids from the Hexane Extract of Melia azedarach Fruits and Their Cytotoxic Activities

A defatted fraction obtained from the hexane extract of the fruits of Melia azedarach L. (chinaberry tree; Meliaceae) exhibited cytotoxic activities against leukemia (HL60), lung (A549), stomach (AZ521), and breast (SK‐BR‐3) cancer cell lines with IC₅₀ values in the range of 2.9–21.9 μg/ml. Three new limonoids, 3‐deacetyl‐4′‐demethylsalannin ( 5 ), 3‐deacetyl‐28‐oxosalannin ( 14 ), and 1‐detigloylohchinolal ( 17 ), along with 16 known limonoids, 1 – 4, 6 – 13, 15, 16, 18 , and 19 , and one known triterpenoid, 20 , were isolated from the fraction. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses and comparison with literature. These compounds were evaluated for their cytotoxic activities against the four cancer cell lines mentioned above. 3‐Deacetyl‐4′‐demethyl‐28‐oxosalannin ( 16 ), which exhibited potent cytotoxicity against AZ521 (IC₅₀ 3.2 μM ) cells, induced typical apoptotic cell death in AZ521 cells upon evaluation of the apoptosis‐inducing activity by flow cytometry. This work provided, furthermore, valuable information on the structural features of limonoids of the fruits and/or seeds of Melia azedarach and related Meliaceae plants, M. toosendan and Azadirachta indica.     

Chemical Constituents of the Vietnamese Marine Sponge Gelliodes sp. and Their Cytotoxic Activities

A new decenoic acid derivative, gelliodesinic acid, and a naturally new alkaloid, together with three known furanoterpenoids and two known indole alkaloids, were isolated from the MeOH extract of the marine sponge Gelliodes sp. collected in Vietnam. The chemical structures of the isolated compounds were determined by analyses of 1D‐ and 2D‐NMR and MS data and by comparisons of the data with those reported in the literature. The cytotoxicity assay against HeLa, MCF‐7, and A549 cancer cell lines revealed that the three known furanoterpenes exhibited cytotoxic activities with IC₅₀ values ranging from 23.6 to 75.5 μM against the three cell lines, and that 1H‐indole‐3‐carboxylic acid showed cytotoxicity with an IC₅₀ value of 89.2 μM against A549 cancer cell lines.     

Chemical Constituents of Crinum asiaticum L. var. sinicum Baker and Their Cytotoxic Activities

A phytochemical investigation of the bulbs of Crinum asiaticum L. var. sinicum Baker resulted in the isolation of two new alkaloids, asiaticumines A and B ( 1 and 2 , resp.), together with 21 known compounds, including nine alkaloids, four amides, five phenolic compounds, and three flavonoids. All 23 compounds were isolated for the first time from Crinum asiaticum L. var. sinicum Baker . Their structures were elucidated by spectroscopic methods. In addition, ten alkaloids, 1 – 10 , were evaluated for their cytotoxic activities against human tumor cell lines A549, LOVO, HL‐60, and 6T‐CEM. Compounds 3, 4 , and 7 – 10 selectively showed remarkable inhibition against one or more of the tested cell lines.     

Biological Activities of Phenolics from the Fruits of Phyllanthus emblica L. (Euphorbiaceae)

Seven phenolic compounds, 1 – 7 , including a new organic acid gallate, mucic acid 1‐ethyl 6‐methyl ester 2‐O‐gallate ( 7 ), were isolated from the MeOH extract of the fruits of Phyllanthus emblica L. (Euphorbiaceae). The structures were elucidated on the basis of extensive spectroscopic analysis and comparison with literature data. Upon evaluated for their antioxidant abilities by 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), 2,2′‐azinobis(3‐ethylbenzthiazoline‐6‐sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. The inhibitory activities against melanogenesis in B16 melanoma cells induced by α‐MSH, as well as cytotoxic activities against four human cancer cell lines were also evaluated. All phenolic compounds, 1 – 7 , exhibited potent antioxidant abilities (DPPH: IC₅₀ 5.6 – 12.9 μm ; ABTS: 0.87 – 8.43 μm Trolox/μm ; FRAP: 1.01 – 5.79 μm Fe²⁺/μm , respectively). Besides, 5 – 7 , also exhibited moderate inhibitory activities against melanogenesis (80.7 – 86.8% melanin content), even with no or low toxicity to the cells (93.5 – 101.6% cell viability) at a high concentration of 100 μm . Compounds 1 – 3 exhibited cytotoxic activity against one or more cell lines (IC₅₀ 13.9 – 68.4%), and compound 1 with high tumor selectivity for A549 (SI 3.2).     

Cytotoxic Activities of Amino Acid‐Conjugate Derivatives of Abietane‐Type Diterpenoids against Human Cancer Cell Lines

Nine amino acid conjugate derivatives, each 2 – 10 and 12 – 20 , were prepared from abietic acid ( 1 ) and dehydroabietic acid ( 11 ), respectively, and they were evaluated for their cytotoxicities against four human cancer cell lines, i.e., leukemia (HL60), lung (A549), stomach (AZ521), and breast (SK‐BR‐3). All compounds showed cytotoxicities against HL60 with IC₅₀ values in the range of 2.3–37.3 μM . In addition, most of the derivatives exhibited moderate cytotoxicities against the other cancer cell lines. Among the derivatives, methyl N‐[18‐oxoabieta‐8,11,13‐trien‐18‐yl]‐L ‐tyrosinate ( 19 ) exhibited potent cytotoxic activities against four cancer cell lines with IC₅₀ values of 2.3 (HL60), 7.1 (A549), 3.9 (AZ521), and 8.1 μM (SK‐BR‐3). Furthermore, all derivatives were shown to possess high selective cytotoxic activities for leukemia cells, since they exhibited only weak cytotoxicities against normal lymphocyte cell line RPMI1788.     

Two New Dolabrane Diterpenes from the Chinese Mangrove Ceriops tagal

Two new dolabrane diterpenes, tagalenes J and K ( 1 and 2 ), together with eleven known analogues ( 3 – 13 ), were isolated from the ethanolic extract of the Chinese mangrove Ceriops tagal. The structures of these compounds were determined by extensive spectroscopic analysis, including 1D‐, 2D‐NMR and HR‐ESI‐MS, as well as the comparison with data in the literatures. Cytotoxicities of isolated compounds against MCF‐7, SW480, HepG2, HeLa, PANC‐1, and A2058 cancer cell lines were also evaluated. Compound 4 exhibited weak cytotoxic activity against SW480, HeLa, and PANC‐1 cell lines with IC₅₀ values of 27.7, 22.2, and 17.6 μm , respectively.     

Dinorcassane Diterpenoid from Boesenbergia rotunda Rhizomes Collected in Lower Myanmar

A new dinorcassane diterpenoid, seikphoochinal A ( 1 ), and four known compounds, pinostrobin ( 2 ), 4′,7‐dimethylkaempferol ( 3 ), and galanals A ( 4 ) and B ( 5 ), were isolated from the chloroform‐soluble crude extract of wild type Boesenbergia rotunda rhizomes collected in Lower Myanmar. The chemical structures of these compounds were identified, using a combination of spectroscopic methods. The presence of the diterpenoids 1 , 4 , and 5 demonstrated the structural diversity of wild type B. rotunda. Among the isolates, compounds 4 and 5 exhibited significant antiproliferative activities against a small panel of human cancer cell lines, including lung (LK‐2, A549), stomach (ECC4), breast (MCF7), cervix (HeLa), and prostate (DU145).     

Limonoids and Flavonoids from the Flowers of Azadirachta indica var. siamensis,and Their Melanogenesis‐Inhibitory and Cytotoxic Activities

A new limonoid, 7‐O‐acetyl‐7‐O‐debenzoyl‐22‐hydroxy‐21‐methoxylimocinin ( 2 ), and two new flavonoids, 3′‐(3‐hydroxy‐3‐methylbutyl)naringenin ( 7 ) and 4′‐O‐methyllespedezaflavanone C ( 9 ), along with nine known compounds, including two limonoids, 1 and 3 , and seven flavonoids, 4 – 6, 8 , and 10 – 12 , were isolated from a MeOH extract of the flowers of Azadirachta indica A.Juss. var. siamensis Valeton (Siamese neem tree; Meliaceae). The structures of new compounds were elucidated on the basis of extensive spectroscopic analysis and comparison with literature data. All of these compounds were evaluated for their melanogenesis‐inhibitory activities in B16 melanoma cells induced with α‐melanocyte‐stimulating hormone (α‐MSH). Compound 2 (16.9% melanin content at 30 μM ), 6‐deacetylnimbin ( 3 ; 49.6% melanin content at 100 μM ), and kaempferide ( 10 ; 41.7% melanin content at 10 μM ) exhibited inhibitory effects with no, or almost no, toxicity to the cells (81.0–111.7% cell viability). In addition, evaluation of their cytotoxic activities against HL60, A549, AZ521, and SK‐BR‐3 human cancer cell lines, isoazadironolide ( 1 ), 4′‐O‐methyl‐8‐prenylnaringenin ( 5 ), euchrestaflavanone A ( 8 ), 9 , and 3‐methoxy‐3′‐prenylnaringenin ( 12 ) revealed potent cytotoxicities against one or more cell lines with IC₅₀ values in the range of 4.5–9.9 μM .     

Alkaloids from Cephalotaxus lanceolata and Their Cytotoxicities

A phytochemical investigation of the branches and leaves of Cephalotaxus lanceolata resulted in the isolation of three new cephalotaxus alkaloids, cephalancetines A, B, and D ( 1, 2 , and 4 , resp.), together with ten known alkaloids, 3 and 5 – 13 . The structures of the alkaloids were elucidated on the basis of spectroscopic analyses, including 1D‐ and 2D‐NMR, and HR‐ESI‐MS, and single‐crystal X‐ray diffraction. All isolated compounds were tested for their cytotoxicities against four human tumor cell lines, A549, HCT116, SK‐BR‐3, and HepG2. Compounds 12 and 13 showed remarkable activities against A549, HCT116, and HepG2 cell lines.     

Cytotoxic and Antimicrobial Activity of Dehydrozingerone based Cyclopropyl Derivatives

A small series of 1‐acetyl‐2‐(4‐alkoxy‐3‐methoxyphenyl)cyclopropanes was prepared, starting from dehydrozingerone (4‐(4‐hydroxy‐3‐methoxyphenyl)‐3‐buten‐2‐one) and its O‐alkyl derivatives. Their microbiological activities toward some strains of bacteria and fungi were tested, as well as their in vitro cytotoxic activity against some cancer cell lines (HeLa, LS174 and A549). All synthesized compounds showed significant antimicrobial activity and expressed cytotoxic activity against tested carcinoma cell lines, but they showed no significant influence on normal cell line (MRC5). Butyl derivative is the most active on HeLa cells (IC₅₀ = 8.63 μm ), while benzyl one is active against LS174 and A549 cell lines (IC₅₀ = 10.17 and 12.15 μm , respectively).     

New Glycerolipids from the Traditional Chinese Medicine of Syngnathus acus (Hai-Long)

Two new glycerolipids, syngaculipids A and B ( 1 and 2 ), one first naturally occurring metabolite ( 8 ), together with five known compounds ( 3 – 7 ) were isolated from the AcOEt fraction of Syngnathus acus L. (Hai-Long). Their structures were elucidated by comprehensive spectral analyses involving UV, IR, MS, 1D and 2D NMR spectra and ECD calculations. All the isolated compounds were evaluated for their cytotoxicity against A549 and HCT-116 cell lines. Compound 8 exhibited moderate cytotoxicity with IC₅₀ values of 34.5 and 38.9 μM on the A549 and HCT-116 cell lines, respectively.     

Lupane‐ and Friedelane‐Type Triterpenoids from Celastrus stylosus

Two new triterpenoids, 30‐hydroxylup‐20(29)‐ene 3β‐caffeate ( 1 ) and 24‐nor‐friedelan‐6α,10‐dihydroxy‐1,2‐dioxo‐4,7‐dien‐29‐oic acid ( 2 ), together with eight known compounds 3 – 10 , were isolated from the roots of Celastrus stylosus. The structures of these compounds were elucidated on the basis of spectroscopic analyses. To the best of our knowledge, this represents the first study on the chemical constituents of C. stylosus. The antiproliferative activities of the triterpenoids against six human cancer cell lines (PANC‐1, A549, PC‐3, HepG2, SGC‐7901, and HCCLM3) were evaluated. Compounds 3, 4 , and 10 exhibited comparable activities against PC‐3 and HCCLM3 cell lines as the positive control taxol.     

Cytotoxic Grifolin Derivatives Isolated from the Wild Mushroom Boletus pseudocalopus (Basidiomycetes)

Activity‐guided purification of a MeOH extract of the Korean wild mushroom Boletus pseudocalopus afforded three new grifolin derivatives, 1 – 3 , along with four known phenolic compounds 4 – 7 . Their structures were established by a combination of ¹H‐ and ¹³C‐NMR, NOESY, and extensive two‐dimensional NMR spectroscopic experiments such as gCOSY, gHSQC, gHMBC, and ROESY. The major metabolites 4 and 5 were subjected to reduction to provide the side chain‐reduced compounds 8 and 9 for biological testing. All of the compounds except compound 6 showed anticancer activities in the range of IC₅₀ 3.5–11.0 μg/ml against human lung carcinoma A549 and mouse melanoma B16F1 cell lines. In addition, all compounds showed moderate radical‐scavenging activities determined by DPPH assay.