The Constituents of Lindera Glauca

Twenty‐eight compounds including seven alkaloids, (+)‐3‐chloro‐N‐formylnornantenine ( 1 ), (+)‐N‐formylnornantenine ( 2 ), (+)‐boldine ( 3 ), (+)‐norboldine ( 4 ), (‐)‐norboldine ( 5 ), lycicamine ( 6 ), and tetrahydroberberine ( 7 ); four flavonoids, kaempferol ( 8 ), kaempferol‐3‐O‐arabinoside ( 9 ), quercetin ( 10 ), and quercetin‐3‐O‐rhamnoside ( 11 ); one butanolide, akolactone A ( 12 ); one p‐quinone, 2,6‐dimethoxy‐p‐quinone ( 13 ); one cyclohex‐2‐en‐1‐one, blumenol A ( 14 ); six benzenoids, methylparaben ( 15 ), p‐hydroxybenzoic acid ( 16 ), vanillic acid ( 17 ), syringic acid ( 18 ), 3,4,5‐trimethoxybenzoic acid ( 19 ), and 3‐(3,4‐dihydroxyphenyl) propionic acid ( 20 ); one diterpene, phytol ( 21 ); one triterpene, squalene ( 22 ); six steroids, (3‐sitosterol ( 23 ), β‐sitostenone ( 24 ), stigmasta‐4,22‐dien‐3‐one ( 25 ), 6β‐hydroxy‐β‐sitostenone ( 26 ), 6β‐hydroxystigmasterone ( 27 ), and β‐sitosteryl‐D‐glucoside ( 28 ) were isolated from the aerial part of Lindera glauca. These compounds were characterized and identified by physical and spectral method. All compounds were isolated for the first time from this plant. Among them, (+)‐3‐chloro‐N‐formylnornantenine ( 1 ) is a new one.     

Three New Chromanones from Calea clausseniana

Three new chromanones, uniflorol A acetate ( 1 ), uniflorol B acetate ( 2 ), and 2,2‐dimethyl‐6‐{1‐[(4′‐acetoxy)angeloyloxy]ethyl}chroman‐4‐one ( 3 ), together with the known chromanone 4 , and two known p‐hydroxyacetophenone derivatives, 5 and 6 , were isolated from the CH₂Cl₂ crude extract of the underground parts of Calea clausseniana Baker . The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques.     

Tocopherols and Triterpenoids from Sida acuta

A new tocopherol derivative, 7_a‐methoxy‐α‐tocopherol ( 1 ), and a new taraxastane triterpene, taraxast‐1,20(30)‐dien‐3‐one ( 5 ), together with four known compounds, β‐tocopherol ( 2 ), α‐tocopherol ( 3 ), α‐tocospiro B ( 4 ) and taraxasterone ( 6 ) were isolated from the whole plant of Sida acuta. Their structures were elucidated by spectral analysis including MS, 1D and 2D‐NMR spectroscopy. Among those compounds, compounds 1 , 2 , and 3 showed significant antioxidant effect (EC₅₀ = 86.9, 68.2, and 70.9 μM, respectively) in the DPPH radicals scavenging activity assay.     

Salicassin,an Unprecedented Chalcone?Diterpene Adduct and a Quinone Methide Triterpenoid from Maytenus salicifolia

In continuation of our work on Maytenus salicifolia, we report herein the isolation and structural elucidation of two new compounds, salicassin ( 1 ), a diterpene‐chalcone adduct with an unprecedented C‐framework, and (16β)‐16‐hydroxypristimerin ( 2 ), a quinone methide triterpenoid. Their structures were elucidated on the basis of spectroscopic analysis, including 1D‐ and 2D‐NMR techniques (COSY, ROESY, HSQC, and HMBC). In addition, 22 known compounds were isolated and characterized by comparison of their spectra with reported data. Compound 2 , structurally related to the well known cytotoxic quinone methide triterpenoids, exhibited an antiproliferative effect on HeLa, A‐549, and HL‐60 human cell lines, with IC₅₀ values of 2.2, 3.2, and 2.7 μM , respectively.     

Prenylated Indole Alkaloid Derivatives from Marine Sediment‐Derived Fungus Penicillium paneum SD‐44

Three new prenylated indole alkaloids, including two β‐carbolines, penipalines A and B ( 1 and 2 , resp.), and one indole carbaldehyde derivative, penipaline C ( 3 ), as well as two known indole derived analogs, 4 and 5 , were isolated from the deep‐sea‐sediment derived fungus Penicillium paneum SD‐44 cultured in a 500‐l bioreactor. The structures of the new compounds were determined on the basis of 1D‐ and 2D‐NMR spectroscopy, as well as by high‐resolution mass spectrometry. The new compounds 2 and 3 showed potent cytotoxic activities against A‐549 and HCT‐116 cell lines.     

Highly Oxygenated Triterpenoids from the Marine Red Alga Laurencia mariannensis (Rhodomelaceae)

Two new and one known squalenoid‐derived triterpenoids, namely, laurenmariannol ( 1 ) and (21α)‐21‐hydroxythyrsiferol ( 2 ), and the known thyrsiferol ( 3 ) were isolated and identified from the marine red alga Laurencia mariannensis, which was collected off the coast of Hainan and Weizhou Islands of China. The structures of these compounds were established by means of spectroscopic analyses, as well as by comparison with literature data. Compounds 1 and 2 displayed significant cytotoxic activity against P‐388 tumor cells with IC₅₀ values of 0.6 and 6.6 μg/ml, respectively.     

New Dammarane‐Type Saponins from the Rhizomes of Panax japonicus

Phytochemical investigation of the rhizomes of Panax japonicus C. A. Meyer (Araliaceae) resulted in the isolation of two new dammarane‐type triterpenoid saponins, yesanchinoside R₁ ( 1 ) and yesanchinoside R₂ ( 2 ), together with one new natural product, 6′′′‐O‐acetylginsenoside Re ( 3 ). In addition, 25 known compounds, including 23 triterpenoid saponins, 4 – 26 , β‐sitosterol 3‐O‐β‐D ‐glucopyranoside ( 27 ), and ecdysterone ( 28 ), were also identified. The known saponins 12, 15 , and 18 – 22 were reported for the first time from the title plant. Their structures were elucidated on the basis of detailed spectroscopic analyses, including 1D‐ and 2D‐NMR techniques, as well as acidic hydrolysis.     

Indoloquinazoline Alkaloids from Araliopsis tabouensis

Three new indoloquinazolidine‐type alkaloids, 8,13‐dihydro‐2‐methoxyindolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolin‐5(7H)‐one ( 1 ), 8,13‐dihydro‐2‐methoxy‐13‐methylindolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolin‐5(7H)‐one ( 2 ), and 5,8,13,14‐tetrahydro‐2‐methoxy‐14‐methyl‐5‐oxo‐7H‐indolo[2′,3′: 3,4]pyrido[2,1‐b]quinazolim‐6‐iun chloride ( 3 ) were isolated from Araliopsis tabouensis, together with three known compounds. The structures of the new compounds were determined primarily from 1D‐ and 2D‐NMR analysis. The antimalarial activities of compounds 1 – 5 were evaluated against Plasmodium falciparum D6 and W2 clones. The IC₅₀ values in antimalarial bioassay for compounds 2 – 5 varied from 1.8 to 4.7 μg/ml.     

Chemical Constituents from Strychnos Cathayensis

Secostrychnosin ( 1 ), a new secoiridoid, as well as seven compounds never before isolated from nature: 4‐tert‐butyl‐2‐oxazolidinone ( 2 ), 3‐acetoxyindole ( 3 ), indole‐2‐carboxylic acid ( 4 ), benzocaine ( 5 ), 3‐acetylindole ( 6 ), butylparaben ( 7 ) and 2‐hydroxy‐3‐methoxybenzaldehyde ( 8 ), together with fifty other known compounds, have been isolated from the stem of Strychnos cathayensis. These compounds include twenty‐three alkaloids, twelve benzenoids, four steroids, three flavonoids, three iridoids, two triterpenoids, two secoiridoids, two fatty acids, one lignan, one acetophenone, one coumarin, one chromane, one tetraterpenoid, one tannin, and one organic acid. The structures of these compounds were determined by means of spectralanalyses.     

Chemical Constituents of the Endophytic Fungus Hypoxylon sp. 12F0687 Isolated from Taiwanese Ilex formosana

Bioassay‐guided fractionation of an AcOEt‐soluble fraction of the liquid fermentation of an endophytic fungus Hypoxylon sp. BCRC 12F0687 associated with the root of Taiwanese Ilex formosana (Aquifoliaceae) resulted in the isolation of two new compounds, i.e., one benzenoid, hypoxyphenone ( 1 ), and one azaphilone derivative, hypoillexidiol ( 2 ), two metabolites isolated for the first time from natural source, (?)‐(3S)‐3‐hydroxy‐3‐methyloxindole ( 3 ) and (+)‐vermelone ( 4 ), along with twelve previously identified compounds, 5 – 16 . Their structures were determined through in‐depth spectroscopic and mass‐spectrometric analyses. The effects of some isolates on the inhibition of NO and IL‐6 production in lipopolysaccharide‐activated RAW 264.7 murine macrophages were evaluated. Of the isolates, 2 and 3 exhibited potent anti‐NO production activity, with IC₅₀ values of 17.5±1.8 and 24.7±1.6 μM , respectively, compared to that of quercetin, an iNOS inhibitor with an IC₅₀ value of 35.9±1.7 μM . Compounds 2, 4, 5 , and 12 also showed moderate inhibition of IL‐6 production, with IC₅₀ values ranging from 27.2±1.8 to 35.3±5.8 μM . This is the first report on an oxindole metabolite from the genus Hypoxylon.     

Additional Minor Phytoecdysteroids of Serratula wolffii

Three new and one known ecdysteroids were identified in the MeOH extract of the roots of Serratula wolffii. The new compounds isolated were (11α)‐11‐hydroxyshidasterone ( 1 ), (2β,3α,5β,14β,22R)‐2,3,20,22,25‐pentahydroxycholest‐7‐en‐6‐one ( 2 ), and (2β,3α,5β,22R)‐2,3,20,22,25‐pentahydroxycholest‐7‐en‐6‐one ( 3 ), together with the known ponasterone A ( 4 ). This latter compound was now better characterized than earlier. The structures of compounds 1 – 4 were established by extensive spectroscopic techniques, including one‐ and two‐dimensional NMR methods.     

Novel,Complex Flavonoids from Mallotus philippensis (Kamala Tree)

One new flavanone, 4′‐hydroxyisorottlerin ( 2 ), and two new chalcone derivatives, kamalachalcones C ( 3 ) and D ( 4 ), were isolated from Mallotus philippensis (kamala tree). The largest compound ( 4 ; M_r 1098 g/mol) was shown to possess a unique, fused‐ring system made of two hydroxy‐chalcone units, giving rise to eight fused benzene/pyran units. From the same plant, the following six known compounds were also isolated: kamalachalcone A ( 5 ) and B ( 6 ), isoallorottlerin ( 7 ), isorottlerin ( 8 ), 5,7‐dihydroxy‐8‐methyl‐6‐prenylflavanone ( 9 ); 6,6‐dimethylpyrano(2″,3″: 7,6)‐5‐hydroxy‐8‐methylflavanone ( 10 ), and rottlerin ( 1 ). The structures of the new compounds were confirmed by in‐depth spectral analyses, including 2D‐NMR techniques, and the full ¹³C‐NMR assignments of the known flavanones 1 and 7 – 10 are published for the first time.     

The Constituents of Euchresta Formosana

A new flavanone, euchrenone a₁₇ ( 1 ), along with eighteen known compounds, glabrol ( 2 ), euchrenone a₂ ( 3 ), formononetin ( 4 ), 7‐methoxy‐2′,4′‐dihydroxyisoflavone ( 5 ), 3‐(3,4‐dimethoxy‐phenyl)‐7,8‐dihydroxy‐chromon‐4‐one ( 6 ), 5,7,2′‐trihydroxy‐4′‐methoxyisoflavone ( 7 ), 2′‐hydroxygenistein ( 8 ), euchrenone b₁ ( 9 ), euchrenone b₂ ( 10 ), euchrenone b₁₆ ( 11 ), vanillin ( 12 ), p‐hydroxybenzoic acid ( 13 ), medicagol ( 14 ), octadecyl ferulate ( 15 ), (+)‐syringaresinol ( 16 ), β‐sitosteryl‐D‐glucoside ( 17 ), and a mixture of β‐sitosterol ( 18 ) and stigmasterol ( 19 ), were isolated from the methanolic extracts of the roots of Euchresta formosana. The structures of these compounds were established by means of spectral analysis.     

New Cytotoxic Metabolites from the Marine‐Derived Fungus Penicillium sp. ZLN29

One new penicillide derivative, prenpenicillide ( 1 ), and one new xanthone derivative, prenxanthone ( 2 ), were isolated from the culture extract of the marine‐derived fungus Penicillium sp. ZLN29, together with six known polyketide compounds, 3 – 8 . Their structures were elucidated on the basis of spectroscopic and spectrometric analyses. The cytotoxicities of these eight compounds were evaluated on four tumor‐cell lines by SRB (=sulforhodamine B) or MTT (=3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) methods. Compounds 1 and 3 exhibited weak cytotoxicities against HepG2 cell line with IC₅₀ values of 9.9 and 9.7 μM , respectively.     

Steroidal Alkaloids from the Roots and Rhizomes of Vertrum nigrum L.

Two new steroidal alkaloids, neoverapatuline ( 1 ) and (1β,3α,5β)‐1,3‐dihydroxyjervanin‐12‐en‐11‐one ( 2 ), together with the four known compounds, veratramine ( 3 ), rubijervine ( 4 ), veratrosine ( 5 ), and veratroylzygadenine ( 6 ), were isolated from the roots and rhizomes of Veratrum nigrum L. Their structures were established through combined analyses of physicochemical properties and spectroscopic evidence. All compounds 1 – 6 were tested for their cytotoxicities in vitro against the human glioma cell line SF188.     

Suberosanones A – C,New Metabolites Possessing Cyclopentenone System from the South China Sea Gorgonian Coral Subergorgia suberosa

Two unusual novel bicyclic lactones, suberosanones A and B ( 1 and 2 , resp.), characterized by the co‐occurrence of cyclopentenone and butanolide rings within the same molecule, along with one tricyclic cyclopentenone derivative, suberosanone C ( 3 ), were isolated from the South China Sea gorgonian coral Subergorgia suberosa. Their structures were unambiguously established by detailed spectroscopic analyses (NMR, IR, and HR‐MS). The absolute configurations of 1 and 2 were determined by quantum‐chemical calculations using the time‐dependent density‐functional theory (TDDFT) method. All compounds showed neither antifouling activity against Balanus amphitrite larvae settlement nor antibacterial activity against a panel of bacterial strains at concentrations up to 25 μg/ml.     

A New Indole Alkaloid from Cleome droserifolia

The phytochemical investigations on Cleome droserifolia resulted in the isolation and characterization of a new indole alkaloid, 5‐hydroxy‐2‐methoxy‐1‐methyl‐1H‐indole‐3‐carbaldehyde ( 1 ). The structure elucidation was carried out on the basis of 1D‐ and 2D‐NMR techniques. In addition to 1 , two known aromatic derivatives, veratrol ( 2 ) and 2‐methoxy‐4‐methylacetophenone ( 3 ), were also obtained. All these compounds were purified by repeated column chromatography of the CH₂Cl₂ fraction obtained from MeOH extract of Cleome droserifolia. The structure of the new compound 1 was finally confirmed by the combined 1D (¹H‐ and ¹³C‐) and 2D (H? C correlations; HMBC and HSQC) NMR and IR spectroscopy, mass spectrometry (MS), and UV absorption spectroscopy techniques. The comparison of the physical and spectroscopic data with those in the literature provided evidence for the structure confirmation of known compounds. All the purified compounds were subjected to urease and α‐glucosidase enzymes inhibition. The results showed that compound 1 was more potent with an IC₅₀ value 11.97±2.067 μg/ml towards urease inhibition, while the activity of α‐glucosidase enzyme was marginal.     

Four New Lanostane Triterpenoids from Euphorbia humifusa

Four new lanostane triterpenoids, namely (3β)‐3‐hydroxy‐24‐methylenelanost‐8‐ene‐7,11‐dione ( 1 ), (3β)‐3‐hydroxylanosta‐8,24‐diene‐7,11‐dione ( 2 ), (3β,7α)‐3,7‐dihydroxylanosta‐8,24‐dien‐11‐one ( 3 ), and (3β,11β)‐3,11‐dihydroxylanosta‐8,24‐dien‐7‐one ( 4 ) were isolated from Euphorbia humifusa, together with 2 known compounds. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis and comparison with the related known compounds.     

Two New Megastigmane Glycosides and a New Iridoid Glycoside from Gelsemium elegans

Two new megastigmane glycosides, eleganosides A and B ( 1 and 3 , resp.), and one new iridoid glycoside, gouwenoside A ( 4 ), together with two known compounds, foliasalacioside B₁ ( 2 ) and loganin ( 5 ), were isolated from the aerial parts of Gelsemium elegans (Gardn. et Champ.) Benth. (Loganiaceae). Their structures were elucidated by spectroscopic methods including 1D‐ and 2D‐NMR techniques. The absolute configuration of 1 was determined by CD spectroscopy.     

Structure Elucidation of Two New Diterpenoids from Isodon phyllostachys: Phyllostacins A and B

Two new ent‐kaurane‐derived diterpene derivatives, phyllostacins A ( 1 ) and B ( 2 ), were isolated from the aerial parts of Isodon phyllostachys, together with two known compounds, irroratin A ( 3 ) and serrin B ( 4 ). Both 1 and 2 were found to be present as diastereoisomers. In the case of 1 , the corresponding diastereoisomeric diacetates 5 and 6 were prepared and separated. The structures of the new compounds were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic methods, in combination with MS experiments. In (D₅)pyridine solution, the two epimers of 1 are present in equal amounts, but in CDCl₃ or CD₃OD, the (S)‐epimer predominates in the mixture of hemiacetals.