Triterpenoids from the Roots of Craibiodendron henryi W. W. Smith

A new triterpenoid, 11a.O.trans-p-coumaroyltaraxerol （1）, along with 11 known triterpenoids, taraxerone （2）, taraxerol （3）, 2α,3β,23,24-tetrahydroxyolean-12-en-28-oic acid （4）, oleanolic acid （5）, β-amyrin （6）, 3β,23-dihydroxylursan-12-en- 28-oic acid （7）, 2α,3β-dihydroxyursan-12-en-28-oic acid （8）, 2α,3β,23-trihydroxyursan-12-en-28-oic acid （9）, 2α,3β,24- trihydroxyursan-12-en-28-oic acid （10）, u rsolic acid （11）, and 3-O-acetylursolic acid （12）, was isolated from Craibiodendron henryi W. W. Smith （Ericaceae）. The structures of these compounds were elucidated on the basis of spectral evidence. Antioxidant activity and vasodilator effect of compound 1 were assessed.     

Constituents from the Roots of Actinidia chinensis and Their Cytochrome P450 Enzyme Inhibitory Activities

A newly discovered triterpenoid, (2α,3β)‐2,3,23‐trihydroxyurs‐13(18)‐en‐28‐oic acid ( 1 ), along with twelve known compounds ( 2  –  13 ), were isolated from the roots of Actinidia chinensis Planch (Actinidiaceae). Their chemical structures were determined by 1D‐ and 2D‐NMR spectra and mass spectrometry (MS). The crude extracts and six main constituents ( 8  –  13 ) were tested for cytochrome P450 (CYPs) enzyme inhibitory activity. The results showed that, except for compound 8 , compounds 9  –  13 had different inhibitory effects on the cytochrome P450 (CYPs) enzyme, and compound 9 significantly inhibited the catalytic activities of CYP3A4 to < 10% of its control activities.     

Chemical Constituents of the Rare Cliff Plant Oresitrophe rupifraga and Their Antineuroinflammatory Activity

Four new ( 1 – 4 ) and thirteen known ( 5 – 17 ) compounds were isolated from a rare cliff plant, Oresitrophe rupifraga. Based on spectroscopic evidence, the new structures were established to be [(2S,3R,4R)‐4‐(4‐methoxybenzyl)‐2‐(4‐methoxyphenyl)‐tetrahydrofuran‐3‐yl]methanol ( 1 ), (3α)‐23‐(acetyloxy)‐3‐hydroxyolean‐12‐en‐29‐oic acid ( 2 ), 3α,23‐(isopropylidenedioxy)olean‐12‐en‐29‐oic acid ( 3 , artifact of isolation), and (3β,15β)‐3‐hydroxycholest‐5‐en‐15‐yl β‐d ‐glucopyranoside ( 4 ), respectively. Among the isolates, compounds 1 , 4 , epieudesmin ( 7 ), and 1‐O‐(9Z,12Z,15Z‐octadecatrienoyl)glycerol ( 17 ) were found to show significant antineuroinflammatory effects by inhibiting the NO production in lipopolysaccharide (LPS)‐stimulated murine BV‐2 microglial cells, with IC₅₀ values of 7.21, 9.39, 4.96, and 8.51 μm , respectively.     

Pinecone of Pinus koraiensis Inducing Apoptosis in Human Lung Cancer Cells by Activating Caspase‐3 and its Chemical Constituents

Pinecones from Pinus koraiensisSiebold & Zucc . (Pinaceae), which have historically been treated as an undesired waste by‐product in the processing of seeds, have recently been shown to contain ingredients with potent biological activities, such as polyphenols exhibiting antitumor activity. With this study, we seek to broaden our understanding of antitumor compounds contained in these pinecones beyond just polyphenols. We found that the water extract of P. koraiensis pinecones exhibits significant cytotoxic activity, with IC₅₀ values ranging from 0.62 to 1.73 mg/ml in four human lung cancer cell lines, A549, H1264, H1299, and Calu‐6, irrespective of their p53 status. We also demonstrate that pinecone water extract induces apoptosis associated with caspase‐3 activation in the same cancer cell lines. Chemical investigation of the pinecone water extract revealed eight main components ( 1  –  8 ), and their structures were identified as dehydroabietic acid ( 1 ), 15‐hydroxy‐7‐oxodehydroabietic acid ( 2 ), 7β,15‐dihydroxydehydroabietic acid ( 3 ), β‐d ‐glucopyranosyl labda‐8(17,13)‐diene‐(15,16)‐lactone‐19‐oate ( 4 ), 7α,15‐dihydroxydehydroabietic acid ( 5 ), (+)‐(1S,2S,4R)‐limonene‐1,2‐diol ( 6 ), sobrerol ( 7 ), and 4‐hydroxybenzoic acid ( 8 ). These findings suggest a novel biological application of P. koraiensis pinecones in combatting human lung cancer, and further identify the major compounds that could contribute to this anticancer activity.     

Cytotoxic Oleanane‐Type Saponins from the Leaves of Albizia anthelmintica Brongn.

Two new oleanane‐type saponins: β‐d ‐xylopyranosyl‐(1 → 4)‐6‐deoxy‐α‐l ‐mannopyranosyl‐(1 → 2)‐1‐O‐{(3β)‐28‐oxo‐3‐[(2‐O‐β‐d ‐xylopyranosyl‐β‐d ‐glucopyranosyl)oxy]olean‐12‐en‐28‐yl}‐β‐d ‐glucopyranose ( 1 ) and 1‐O‐[(3β)‐28‐oxo‐3‐{[β‐d ‐xylopyranosyl‐(1 → 2)‐α‐l ‐arabinopyranosyl‐(1 → 6)‐2‐acetamido‐2‐deoxy‐β‐d ‐glucopyranosyl]oxy}olean‐12‐en‐28‐yl]β‐d ‐glucopyranose ( 2 ), along with two known saponins: (3β)‐3‐[(β‐d ‐Glucopyranosyl‐(1 → 2)‐β‐d ‐glucopyranosyl)oxy]olean‐12‐en‐28‐oic acid ( 3 ) and (3β)‐3‐{[α‐l ‐arabinopyranosyl‐(1 → 6)‐[β‐d ‐glucopyranosyl‐(1 → 2)]‐β‐d ‐glucopyranosyl]oxy}olean‐12‐en‐28‐oic acid ( 4 ) were isolated from the acetone‐insoluble fraction obtained from the 80% aqueous MeOH extract of Albizia anthelmintica Brongn . leaves. Their structures were identified using different NMR experiments including: ¹H‐ and ¹³C‐NMR, HSQC, HMBC and ¹H,¹H‐COSY, together with HR‐ESI‐MS/MS, as well as by acid hydrolysis. The four isolated saponins and the fractions of the extract exhibited cytotoxic activity against HepG‐2 and HCT‐116 cell lines. Compound 2 showed the most potent cytotoxic activity among the other tested compounds against the HepG2 cell line with an IC₅₀ value of 3.60μm . Whereas, compound 1 showed the most potent cytotoxic effect with an IC₅₀ value of 4.75μm on HCT‐116 cells.     

Piptadenin,a Novel 3,4‐Secooleanane Triterpene and Piptadenamide,a New Ceramide from the Stem Bark of Piptadeniastrum africanum (Hook.f.) Brenan

Piptadenin ( 1 ), a new triterpene along with piptadenamide ( 10 ), a new ceramide, have been isolated from the AcOEt‐soluble fraction of the MeOH extract of the stem bark of Piptadeniastrum africanum along with nine known compounds, 1‐O‐[(3β,22β)‐3,22‐dihydroxy‐28‐oxoolean‐12‐en‐28‐yl]‐β‐d ‐glucopyranose ( 2 ), 22β‐hydroxyoleanic acid ( 3 ), oleanic acid ( 4 ), lupeol ( 5 ), betulinic acid ( 6 ), 5α‐stigmasta‐7,22‐dien‐3β‐ol ( 7 ), 5α‐stigmasta‐7,22‐dien‐3‐one ( 8 ), (3β)‐stigmast‐5‐en‐3‐yl β‐d ‐glucopyranoside ( 9 ) and 2,3‐dihydroxypropyl hexacosanoate ( 11 ). Except for compound 11 , all the isolated compounds are reported for the first time from this plant. The structures of the isolated compounds were elucidated by spectroscopic data including 1D and 2D NMR. The pure compounds 1 – 11 were subjected to the pharmacological screening and compounds 2 , 5 – 7 and 9 exhibited potent urease inhibitory activity with IC₅₀ value of 25.8, 28.9, 30.1, 31.8 and 32.7 μm , respectively, whereas compound 1 showed moderate activity (IC₅₀ = 98.7 μm ). The potent urease inhibitory activity supplemented the previous literature reports and medicinal uses of this plant.     

Inhibition of NO Production by Grindelia argentina and Isolation of Three New Cytotoxic Saponins

A bioassay‐guided phytochemical analysis of the ethanolic extract of Grindelia argentina Deble & Oliveira ‐Deble (Asteraceae) allowed the isolation of a known flavone, hispidulin, and three new oleanane‐type saponins, 3‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐apiofuranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→3)‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl ester ( 2 ), 3‐O‐β‐D ‐glucopyranosyl‐2β,3β,23‐trihydroxyolean‐12‐en‐28‐oic acid 28‐O‐β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐apiofuranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→3)‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl ester, ( 3 ) and 3‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐2β,3β,23‐trihydroxyolean‐12‐en‐28‐oic acid 28‐O‐β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐apiofuranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→3)‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl ester ( 4 ), named grindeliosides A–C, respectively. Their structures were determined by extensive 1D‐ and 2D‐NMR experiments along with mass spectrometry and chemical evidence. The isolated compounds were evaluated for their inhibitory activities against LPS/IFN‐γ‐induced NO production in RAW 264.7 macrophages and for their cytotoxic activities against the human leukemic cell line CCRF‐CEM and MRC‐5 lung fibroblasts. Hispidulin markedly reduced LPS/IFN‐γ‐induced NO production (IC₅₀ 51.4 μM ), while grindeliosides A–C were found to be cytotoxic, with grindelioside C being the most active against both CCRF‐CEM (IC₅₀ 4.2±0.1 μM ) and MRC‐5 (IC₅₀ 4.5±0.1 μM ) cell lines.     

Melanogenesis‐Inhibitory and Cytotoxic Activities of Limonoids,Alkaloids, and Phenolic Compounds from Phellodendron amurense Bark

Four limonoids, 1  –  4 , five alkaloids, 5  –  9 , and four phenolic compounds, 10  –  13 , were isolated from a MeOH extract of the bark of Phellodendron amurense (Rutaceae). Among these, compound 13 was new, and its structure was established as rel‐(1R,2R,3R)‐5‐hydroxy‐3‐(4‐hydroxy‐3‐methoxyphenyl)‐6‐methoxy‐1‐(methoxycarbonylmethyl)indane‐2‐carboxylic acid methyl ester (γ‐di(methyl ferulate)) based on the spectrometric analysis. Upon evaluation of compounds 1  –  13 against the melanogenesis in the B16 melanoma cells induced with α‐melanocyte‐stimulating hormone (α‐MSH), four compounds, limonin ( 1 ), noroxyhydrastinine ( 6 ), haplopine ( 7 ), and 4‐methoxy‐1‐methylquinolin‐2(1H)‐one ( 8 ), exhibited potent melanogenesis‐inhibitory activities with almost no toxicity to the cells. Western blot analysis revealed that compound 6 inhibited melanogenesis, at least in part, by inhibiting the expression of protein levels of tyrosinase, TRP‐1, and TRP‐2 in α‐MSH‐stimulated B16 melanoma cells. In addition, when compounds 1  –  13 were evaluated for their cytotoxic activities against leukemia (HL60), lung (A549), duodenum (AZ521), and breast (SK‐BR‐3) cancer cell lines, five compounds, berberine ( 5 ), 8 , canthin‐6‐one ( 9 ), α‐di‐(methyl ferulate) ( 12 ), and 13 , exhibited cytotoxicities against one or more cancer cell lines with IC₅₀ values in the range of 2.6 – 90.0 μm . In particular, compound 5 exhibited strong cytotoxicity against AZ521 (IC₅₀ 2.6 μm ) which was superior to that of the reference cisplatin (IC₅₀ 9.5 μm ).     

Six New Polyhydroxysteroidal Glycosides,Anthenosides S1 – S6, from the Starfish Anthenea sibogae

Six new polyhydroxysteroidal glycosides, anthenosides S1  –  S6 ( 1  –  6 ), along with a mixture of two previously known related glycosides, 7 and 8 , were isolated from the methanolic extract of the starfish Anthenea sibogae. The structures of 1  –  6 were established by NMR and HR‐ESI‐MS techniques as well as by chemical transformations. All new compounds have a 5α‐cholest‐8(14)‐ene‐3α,6β,7β,16α‐tetrahydroxysteroidal nucleus and differ from majority of starfish glycosides in positions of carbohydrate moieties at C(7) and C(16) ( 1  –  4 , 6 ) or only at C(16) ( 5 ). The 4‐O‐methyl‐β‐d ‐glucopyranose residue ( 2 ) and Δ²⁴‐cholestane side chain ( 3 ) have not been found earlier in the starfish steroidal glycosides. The mixture of 7 and 8 slightly inhibited the proliferation of human breast cancer T‐47D cells and decreased the colony size in the colony formation assay.     

Triterpene Saponins from the Roots of Ilex asprella

Six new triterpene saponins, ilexasprellanosides A–F ( 1 – 6 , resp.), together with eleven known compounds were isolated from the roots of Ilex asprella. The new saponins were characterized as ursa‐12,18‐dien‐28‐oic acid 3‐O‐β‐D ‐xylopyranoside ( 1 ), 19α‐hydroxyursolic acid 3‐O‐β‐D ‐(2′‐O‐acetylxylopyranoside) ( 2 ), 19α‐hydroxyursolic acid 3‐O‐β‐D ‐glucuronopyranoside ( 3 ), 3β,19α‐dihydroxyolean‐12‐en‐23,28‐dioic acid 28‐O‐β‐D ‐glucopyranoside ( 4 ), 19α‐hydroxyoleanolic acid 3‐O‐β‐D ‐(2′‐O‐acetylxylopyranoside) ( 5 ), 19α‐hydroxyoleanolic acid 3‐O‐β‐D ‐glucuronopyranoside ( 6 ). The structures of the new compounds were elucidated by analysis of their spectroscopic data and chemical degradation. Compounds 2, 4 , oleanolic acid 3‐O‐β‐D ‐glucuronopyranoside, 3‐β‐acetoxy‐28‐hydroxyurs‐12‐ene, and pomolic acid showed significant cytotoxic activities against human tumor cell line A549 (IC₅₀ values of 1.87, 2.51, 1.41, 3.24, and 5.63 μM , resp.).     

Exploration of Phytoconstituents from Mussaenda roxburghii and Studies of Their Antibiofilm Effect

In the context of ethno botanical importance with no phytochemical investigations, Mussaenda roxburghii have been investigated to explore it's phytoconstituents and studies of their antibiofilm activity. Four compounds have been isolated from the aerial parts of this plant and were characterized as 2α,3β,19α,23‐tetrahydroxyurs‐12‐en‐28‐oic acid ( 1 ), β‐sitosterol glucoside ( 4 ), lupeol palmitate ( 5 ), and myoinositol ( 6 ). All these compounds were tested for antibacterial and antibiofilm activity against Pseudomonas aeruginosa. Compound 1 exhibited three times more antibiofilm activity with minimum inhibitory concentration (MIC) at 0.74 mm compared to that of streptomycin. Molecular docking studies exhibited a very high binding affinity of 1 with P. aeruginosa quorum sensing proteins and motility associated proteins viz. LasR and PilB, PilY1, PilT, respectively. Compound 1 was also found to be non‐cytotoxic against sheep RBC and murine peritoneal macrophages at selected sub‐MIC doses.     

Oleanane‐type Saponins from Glochidion hirsutum and Their Cytotoxic Activities

Five new oleanane‐type saponins, hirsutosides A – E, were isolated from the leaves of Glochidion hirsutum (Roxb .) Voigt . Their structures were elucidated as 21β‐benzoyloxy‐3β,16β,23,28‐tetrahydroxyolean‐12‐ene 3‐O‐β‐d ‐glucopyranoside ( 1 ), 21β‐benzoyloxy‐3β,16β,23,28‐tetrahydroxyolean‐12‐ene 3‐O‐β‐d ‐glucopyranosyl‐(1 → 3)‐β‐d ‐glucopyranoside ( 2 ), 21β‐benzoyloxy‐3β,16β,23,28‐tetrahydroxyolean‐12‐ene 3‐O‐6‐acetyl‐[β‐d ‐glucopyranosyl‐(1 → 3)]‐β‐d ‐glucopyranoside ( 3 ), 21β‐benzoyloxy‐3β,16β,23,28‐tetrahydroxyolean‐12‐ene 3‐O‐β‐d ‐glucopyranosyl‐(1 → 3)‐〈‐l ‐arabinopyranoside ( 4 ), and 21β‐benzoyloxy‐3β,16β,23‐trihydroxyolean‐12‐ene‐28‐al 3‐O‐β‐d ‐glucopyranosyl‐(1 → 3)‐α‐l ‐arabinopyranoside ( 5 ). All isolated compounds were evaluated for cytotoxic activities on four human cancer cell lines, HepG‐2, A‐549, MCF‐7, and SW‐626 using the SRB assay. Compounds 1 , 2 , 4 , and 5 showed significant cytotoxic activities against all human cancer cell lines with IC₅₀ values ranging from 3.4 to 10.2 μm . Compound 3 containing acetyl group at glc C(6″) exhibited weak cytotoxic activity with IC₅₀ values ranging from 47.0 to 54.4 μm .     

Phytochemical Investigation and Cytotoxic Evaluation of the Components of the Medicinal Plant Ligularia atroviolacea

A phytochemical investigation of the roots of Ligularia atroviolacea resulted in the isolation of 24 compounds including seven new eremophilanoids named eremophila‐3,7(11),8‐triene‐12,8;14,6α‐diolide ( 1 ), 3β‐(angeloyloxy)eremophil‐7(11)‐en‐12,8β‐olid‐14‐oic acid ( 2 ), 1α‐chloro‐10β‐hydroxy‐6β‐(2‐methylpropanoyloxy)‐9‐oxo‐7,8‐furoeremophilane ( 3 ), (10βH)‐8‐oxoeremophila‐3(4),6(7)‐diene‐12,14‐dioic acid ( 4 ), (10αH)‐8‐oxoeremophila‐3(4),6(7)‐diene‐12,14‐dioic acid ( 5 ), 8β‐[eremophila‐3′,7′(11′)‐diene‐12′,8′α;14′,6′α‐diolide]eremophila‐3,7(11)‐diene‐12,8α;14,6α‐diolide ( 6 ), and ligulatrovine A ( 7 ), eleven known eremophilanoids, 8 – 18 , four steroids, one glucose derivative, and one fatty acid. The structures of these compounds were elucidated by spectroscopic methods including 2D‐NMR experiments. The structure of 3 was also established by an X‐ray diffraction study. The in vitro cytotoxicity evaluation of selected compounds was performed on seven cultured tumor cell lines, i.e., KB, BEL‐7404, A549, HL‐60, HeLa, CNE, and P‐388D1. The preliminary taxonomy of this species was also discussed, and the possible biogenesis of a dimer possessing a new noreremophilanoid type skeleton, 7 , is presented in a preliminary form.     

Diterpenoids from Wedelia prostrata and Their Derivatives and Cytotoxic Activities

One new ent‐kaurane diterpenoid, 11β,16α‐dihydroxy‐ent‐kauran‐19‐oic acid ( 1 ), together with eight known analogues 2 – 9 were isolated from the aerial parts of Wedelia prostrata. One of the acidic diterpenoids, kaurenoic acid ( 3 ), was converted to seven derivatives, 10 – 16 . All compounds were evaluated for their cytotoxic activity in vitro against human leukemia (K562), liver (HepG‐2), and stomach (SGC‐7901) cancer cell lines. Only four kaurenoic acid derivatives, 13 – 16 , with 15‐keto and substitutions at C(19) position, exhibited notable cytotoxic activities on these tumor cell lines with IC₅₀ value ranging from 0.05 to 3.71 μm . Compounds 10 – 12 , with oxime on C(15) showed moderate inhibitory effects and compounds 1 – 9 showed no cytotoxicities on them. Structure–activity relationships were also discussed based on the experimental data obtained. The known derivative, 15‐oxokaurenoic acid 4‐piperdin‐1‐ylbutyl ester ( 17 ), induced typical apoptotic cell death in colon SW480 cells upon evaluation of the apoptosis‐inducing activity by flow‐cytometric analysis.     

Herbicidal and Cytotoxic Constituents from Aralia armata (Wall.) Seem.

Two new triterpenoids, 3β‐hydroxyoleana‐11,13(18)‐diene‐28,30‐dioic acid ( 1 ) and 3‐oxooleana‐11,13(18)‐diene‐28,30‐dioic acid ( 2 ), one novel triterpenoid glycoside, 3β‐O‐(6′‐O‐methyl‐β‐d‐ glucuronopyranosyl)oleana‐11,13(18)‐dien‐28‐oic acid ( 3 ) along with six known compounds ( 4  –  9 ) were isolated from the stem bark of Aralia armata (Wall .) Seem . Their structures were elucidated through extensive spectroscopic methods. The herbicidal activities of these compounds against Bidens pilosa L., an invasive weed in P. R. China, were evaluated. Compounds 3 , 5, and 6 exhibited more significant herbicidal activities on B. pilosa than the positive‐control pendimethalin. Their possible use as herbicidal chemicals or model compounds deserved more attention. The effects of compounds 1  –  9 on Spodoptera litura cultured cell line Sl‐1 cell proliferation and its morphology were also evaluated. The results indicated that compounds 1  –  5 affected Sl‐1 cell proliferation. Compound 3 showed more obvious proliferation inhibition activities on Sl‐1 cell than the positive‐control rotenone. With regard to the effect on morphology, compound 2 significantly changed Sl‐1 cell, resulting in cell blebbing and vacuole forming. Triterpenoids aremedicinally and agriculturally important, and cytotoxicity of the three new compounds 1  –  3 deserved further studies.     

Oplopane Sesquiterpenes from Ligularia knorringiana and Their Anti‐Complementary Activity

Three new oplopane sesquiterpenes, knorringianalarins D – F ( 1 – 3 , respectively), and five known analogues ( 4 – 8 , respectively), were isolated from the roots and rhizomes of Ligularia knorringiana. The structures of three new compounds were identified as 4‐acetoxy‐11α,12‐epoxy‐2β‐hydroxy‐3β‐(2‐methylbutyryloxy)‐9α‐(4‐methylsenecioyloxy)oplop‐10(14)‐ene ( 1 ), 3β,4‐diacetoxy‐9α‐(4‐acetoxy‐4‐methylsenecioyloxy)‐11α,12‐epoxy‐8α‐(2‐methylbutyryloxy)oplop‐10(14)‐ene ( 2 ), and (1R,5R,6R,7R,9R)‐5,9,11‐trihydroxy‐4,15‐dinoroplop‐10(14)‐en‐3‐one ( 3 ) based on spectroscopic methods including 1D‐ and 2D‐NMR, mass spectrometry, and CD spectroscopy techniques. All compounds were evaluated for their anti‐complementary activity on the classical pathway of the complement system in vitro. Among which, three oplopane sesquiterpenes ( 3 , 7 , and 8 ) exhibited better anti‐complementary effects with CH₅₀ values ranging from 0.33 to 0.89 mm , which are plausible candidates for developing potent anti‐complementary agents.     

New Triterpenoids from the Fruiting Bodies of Ganoderma lucidum and Their Bioactivities

Phytochemical investigation of the AcOEt extract of G. Lucidum has led to the isolation of two new triterpenoids, 1 and 2 , together with five known ones, 3 – 7 . The structures of the new compounds were identified as 12β‐acetoxy‐3β,7β‐dihydroxy‐11,15,23‐trioxolanost‐8‐en‐26‐oic acid butyl ester ( 1 ) and 12β‐acetoxy‐3,7,11,15,23‐pentaoxolanost‐8‐en‐26‐oic acid butyl ester ( 2 ) on the basis of detailed spectroscopic analysis (mass spectrometry, and 1D‐ and 2D‐NMR experiments). The antimicrobial activities of 1 and 2 were also evaluated.     

Biological Activities of Triterpenoids and Phenolic Compounds from Myrica cerifera Bark

Seven triterpenoids, 1  –  7 , two diarylheptanoids, 8 and 9 , four phenolic compounds, 10  –  13 , and three other compounds, 14  –  16 , were isolated from the hexane and MeOH extracts of the bark of Myrica cerifera L. (Myricaceae). Among these compounds, betulin ( 1 ), ursolic acid ( 3 ), and myricanol ( 8 ) exhibited cytotoxic activities against HL60 (leukemia), A549 (lung), and SK‐BR‐3 (breast) human cancer cell lines (IC₅₀ 3.1 – 24.2 μm ). Compound 8 induced apoptotic cell death in HL60 cells (IC₅₀ 5.3 μm ) upon evaluation of the apoptosis‐inducing activity by flow cytometric analysis and by Hoechst 33342 staining method. Western blot analysis on HL60 cells revealed that 8 activated caspases‐3, ‐8, and ‐9 suggesting that 8 induced apoptosis via both mitochondrial and death receptor pathways in HL60. Upon evaluation of the melanogenesis‐inhibitory activity in B16 melanoma cells induced with α‐melanocyte‐stimulating hormone (α‐MSH), erythrodiol ( 7 ), 4‐hydroxy‐2‐methoxyphenyl β‐d ‐glucopyranoside ( 13 ), and butyl quinate ( 15 ) exhibited inhibitory effects (65.4 – 86.0% melanin content) with no, or almost no, toxicity to the cells (85.9 – 107.4% cell viability) at 100 μm concentration. In addition, 8 , myricanone ( 9 ), myricitrin ( 10 ), protocatechuic acid ( 11 ), and gallic acid ( 12 ) revealed potent DPPH radical‐scavenging activities (IC₅₀ 6.9 – 20.5 μm ).     

Novel 3‐Oxo‐ and 3,24‐Dinor‐2,4‐secooleanane‐Type Triterpenes from Terminalia ivorensis A. Chev.

Two new oleanane‐type triterpenes named ivorengenin A (=3‐oxo‐2α,19α,24‐trihydroxyolean‐12‐en‐28‐oic acid; 1 ) and ivorengenin B (=4‐oxo‐19α‐hydroxy‐3,24‐dinor‐2,4‐secoolean‐12‐ene‐2,28‐dioic acid; 2 ), together with five known compounds, arjungenin, arjunic acid, betulinic acid, sericic acid, and oleanolic acid, were isolated from the barks of Terminalia ivorensis A. Chev . (Combretaceae). Their structures were established on the basis of 1D‐ and 2D‐NMR data, and mass spectrometry. A biogenetic pathway to the formation of these compounds from sericic acid, isolated as the major compound from this plant, was proposed. The antioxidant activities of different compounds were investigated by means of the 2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assays, and IC₅₀ values were calculated and compared with Trolox activity. Antiproliferative activities of the isolated compounds were also evaluated against MDA‐MB‐231, PC3, HCT116, and T98G human cancer cell lines, against which the compounds showed significant cytotoxic activities.     

Sesquiterpenoids and Diterpenoids from Chloranthus anhuiensis

A phytochemical investigation of the roots of Chloranthus anhuiensis afforded three new sesquiterpene lactones, chloraniolide A ( 1 ), (3R)‐3‐hydroxyatractylenolide III ( 2 ), and 8β‐hydroxy‐1‐oxoeudesma‐3,7(11)‐dien‐12,8α‐olide ( 3 ), and two new diterpenoids, (12R,13E)‐15‐(acetoxy)‐12‐hydroxylabda‐8(20),13‐dien‐19‐oic acid ( 4 ) and (12S,13E)‐15‐(acetoxy)‐12‐dihydroxylabda‐8(20),13‐dien‐19‐oic acid ( 5 ), as well as 17 known sesquiterpenoid and diterpenoid compounds. Their structures were established on the basis of 1D‐ and 2D‐NMR, and other spectroscopic analyses.