Two new limonoids from Melia toosendan

Two new limonoid-type triterpenoids, named 12-o-ethyl-l-deacetylnimbolinin B and 1-o-tigloyl-1-o-debenzoylohchinal, have been isolated from the fruit of Melia toosendan Sieb. et Zucc. Their structures were elucidated by spectral methods, including 2D-NMR spectra.

Highly Oxygenated Limonoids and Lignans from Phyllanthus flexuosus

Two new highly oxygenated limonoids,flexuosoids A(1)and B(2),and three new arylnaphthalene lignan glycosides,phyllanthusmins D–F(3–5),were isolated from the roots of Phyllanthus flexuosus,in addition to three known lignans,phyllanthusmin C,arabelline,and(?)-diasyringaresinol.Their structures were elucidated on the basis of detailed spectroscopic analysis and chemical methods.Compounds 1 and 2,two new decaoxygenated limonoids with a C-19/29 lactol bridge and heptaoxygenated substituents at C-1,C-2,C-3,C-7,C-11,C-17,and C-30,represent the second example of limonoids in the Euphorbiaceae family.Most of the isolates were tested for their antifeedant,anti-herpes simplex virus 1,and cytotoxic activities.The new limonoids 1 and 2 showed promising antifeedant activity against the beet army worm(Spodoptera exigua)with EC50 values of 25.1 and 17.3 lg/cm2,respectively.In addition,both of them displayed moderate cytotoxicity against the ECA109 human esophagus cancer cell line,along with the known lignan glycoside,phyllanthusmin C,with the IC50 values of 11.5(1),8.5(2),and 7.8(phyllanthusmin C)lM,respectively.

Five new mexicanolide type limonoids from Heynea trijuga

Five new mexicanolide-type limonoids,heytrijunolides A-E(1-5)were isolated from the branches and leaves of Heynea trijuga.The structures of these new compounds were elucidated on the basis of extensive spectroscopic analysis.Compound 3 showed weak cytotoxicity against HL-60,SMMC-7721 and A-549 human tumor cell lines with the IC50 values of 21.88,20.66 and 12.70μM,respectively.

Limonoids and triterpenoids from the twigs and leaves of Dysoxylum hainanense

Four new limonoids,dysohainanins A-D(1-4),and two new triterpenoids,dysohainanins E and F(5 and 6),together with seven known ones were isolated from the twigs and leaves of Dysoxylum hainanense Merr.The structures of the new compounds were determined by a variety of spectroscopic methods.The cytotoxic activities of these compounds were evaluated,and the known compound ent-19-nor-4,16,18-trihydroxy-8(14)-pomaren-15-one(13)showed in vitro cytotoxicity against HL-60,A-549,MCF-7,and SW480 cells,with IC50 values of 24.3,28.1,30.7,and 22.5mM,respectively.Compounds 2 and 3 were tested their insecticidal activities using brine shrimp and both of them were inactive.

Four New Limonoids from the Barks of Toona ciliata

Four new limonoids,toonayunnanaes F−I(1−4),and six known compounds(5−10)were isolated from the barks of Toona ciliata.Their structures were elucidated by thoroughly analyzing of NMR and HRMS data,and single-crystal X-ray diffraction of 1.The oxetane ring moiety in 1 was rare in limonoids and other natural products.Compound 1 showed nitric oxide(NO)inhibitory effect with an IC5038.45±0.41μM in lipopolysaccharide(LPS)-activated RAW 264.7 macrophages.

Diterpenoids and Limonoids from the Leaves and Twigs of Swietenia mahagoni

Three new compounds,including two diterpenoids,nemoralisins H and I(1 and 2),and a limonoid,2-methoxy khayseneganin E(3),along with four known constituents(4-7),were isolated from the leaves and twigs of Swietenia mahagoni.Their chemical structures were elucidated by means of spectroscopic analysis.The cytotoxities of these isolated constituents were assayed.

New limonoids from the fruits of Melia toosendan

Two new limonoids,1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12α-ethoxyl nimbolinin（1） and lα-benzoyloxy-3α-acetoxyl-7α- hydroxyl-12α-ethoxyl nimbolinin（2）,were isolated from the fruits of Melia toosendan.Their structures were established on the basis of various NMR spectroscopic analyses,including 2D-NMR techniques（HSQC,HMBC,NOESY） and HR-ESI-MS.

Two new phragmalin-type limonoids orthoesters from Entandrophragma candollei

Two new phragmalin-type limonoids orthoesters, encandollens A and B(1 and 2), were isolated from the stem barks of Entandrophragma candollei collected in Ghana. The structures of these compounds were elucidated on the basis of HR-ESI-MS, ~1 H and ^(13) C NMR, HSQC, HMBC, and ROESY data. Compound 1 was a rare C-15 enolic acyl phragmalin-type limonoid orthoester. Compounds 1 and 2 exhibited weak inhibitory effects on NO production in lipopolysaccharide(LPS)-induced RAW 264.7 cells.

Four New Limonoids from Aphanamixis grandifofia

Four new limonoids, named aphanagranins A-D （1-4）, were isolated from the fruits ofAphanamixis grandi- folia. The new structures were determined by spectroscopic methods especially 1D and 2D NMR analysis, Aphana- granin A （1） possessed a rare four membered oxygen heterocyclic ring and its absolute configurations were deter- mined on the basis of the signal crystal X-ray diffraction analysis. Furthermore, compounds 1 and 2 showed weak activity toward brine shrimp （Artemia salina）.

Cipaferoids A-C, Three Limonoids Represent Two Different Scaffolds from Cipadessa baccifera

Three limonoids cipaferoids A-C （1-3） representing two different scaffolds were isolated from Cipadessa baccifera. Their structures were completely assigned by spectroscopic data, CD exciton chirality method, and X-ray crystallography. Compounds 2 and 3 exhibited moderate antimalarial activity with IC50 values of 9.3±0.1 and 14.7±4.8 μmol·L^-1, respectively.

Dysoxylumasins A--F＂ Six New Limonoids from Dysoxylum mollissimum BI.

Six new mexicanolide-type limonoids, dysoxylumasins A-F （1-6）, together with eight known compounds, namely litseagermacrane, 15-methoxyisodauc-3-ene-1β, 5α-diol, isodauc-6-ene-10β,14-diol, 4-epi-isodauc-6-ene- 10β,14-diol, 2a,3a,4β-trihydroxypregnan-16-one, 1,7-phenanthrenedimethanol, spicatin, and aurantiamide, were isolated from the leaves and twigs of Dysoxylum mollissimum B1. Their structures were established by the analyses of spectroscopic data.

Diverse Ring-seco Limonoids from Munronia unifoliolata and Their Biological Activities

Twenty-two new limonoids,mufolinoids A—V(1—22),including six rings A,B-seco limonoids(1—6),twelve ring A-seco limonoids(7—18),four ring-intact limonoids(19—22),together with thirteen known compounds(23—35)were isolated from Munronia unifoliolata.Their structures including absolute configurations were elucidated by combination of NMR,HR-MS,single-crystal X-ray diffraction and calculations of ECD and NMR technologies.Compounds 24,25,33,34 could be significantly reversed the multidrug resistance of MCF-7/doxorubicin(DOX)cells,and the reversal fold(RF)was much higher than that of positive drug Verapamil.Compounds 24,28,and 29 exhibited significant anti-inflammatory activity with the IC50 values in the range of 17.7—39.4μmol/L.Furthermore,compound 29 could markedly inhibit the release of IL-1βby inhibiting the initiation and assembly of NLRP3 inflammasome,which demonstrates the great potential of limonoids as an anti-inflammatory agent.

Highly oxygenous trichilin-type limonoids from Trichilia sinensis

Six new trichilin-type limonoids(1-6)with C-19/29 lactol or acetal bridge and a new ring intact limonoid(7)were isolated from the desiccative ripe fruits of Trichilia sinensis.Their structures were determined by extensive spectroscopic methods including 1 H NMR,13 C NMR,HSQC,HMBC,ROESY experiments as well as HRESI-MS data.All isolated compounds were evaluated for toxicities against human pulmonary carcinoma A549 and Hela cell lines by sulforhodamine B(SRB)method.Compound 7 showed weak inhibitory activity in Hela cell line at 40μmol·L^-1.

New limonoids isolated from the bark of Melia toosendan

Two new limonoids, 12-ethoxynimbolinins G and H(compounds 1 and 2), and one known compound, toosendanin(Chuanliansu)(compound 3), were isolated from the bark of Melia toosendan. Their structures were elucidated by spectroscopic analysis and X-ray techniques. The absolute configuration of toosendanin(3) was established by single-crystal X-ray diffraction. Compounds 1-3 were evaluated for their cytotoxicity against five tumor cell lines.

Two new limonoids isolated from the fuits of Melia toosendan

In the present study, two new limonoids, 1α, 7α-dihydroxyl-3α-acetoxyl-12α-ethoxylnimbolinin(1) and 1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12β-ethoxylnimbolinin(2), together with other four known limonoids(3-6), were isolated from the fruits of Melia toosendan. Their structures were elucidated by means of extensive spectroscopic analyses(NMR and ESI-MS) and comparisons with the data reported in the literature. The isolated compounds were evaluated for their antibacterial activities. Compound 4 exhibited significant antibacterial activity against an oral pathogen, Porphyromonas gingivalis ATCC 33277, with an MIC value of 15.2 μg·m L-1. Compound 2 was also active against P. gingivalis ATCC 33277, with an MIC value of 31.25 μg·m L-1. In conlcusion, our resutls indicate that these compounds may provide a basis for future development of novel antibiotics.

Two new nimbolinin-and trichilin-class limonoids isolated from the fruits of Melia azedarach

Two new furan fragment isomerized limonoids, meliazedalides A and B(compounds 1 and 2), were isolated from the fruits of Melia azedarach Linn.. Their chemical structures were elucidated on the basis of HR-ESI-MS and 1D and 2D NMR data, which belonged to nimbolinin-and trichilin-class, respectively. Compound 2 exhibited weak inhibitory effect on NO production in lipopolysaccharide(LPS)-activated RAW 264.7 macrophages with IC_(50) being 37.41 μmol·L^(–1).

Limonoids from seeds of Azadirachta indica A.Juss. and their cytotoxic activity

Four new limonoid-type nortriterpenoids, 1-detigloyl-1-O-methacryloylsalannin(1), 28-deoxo-2,3-dihydronimbolide(2), 12-acetoxy-3-O-acetyl-7-O-tigloylvilasinin(3) and 12-acetoxy-3-Oacetyl-7-O-methacryloylvilasinin(4), along with five known ones, were isolated from seeds of Azadirachta indica A. Juss. Their structures were elucidated by various spectroscopic methods, including UV, IR, MS, NMR, X-ray crystallography, quantum chemical calculation, as well as by comparison of their spectroscopic data with those reported. In the in vitro cytotoxic assay, 2 showed inhibitory activity against human breast cancer MDA-MB-231 cell line with IC_(50) value of 7.68±1.74 μmol/L, and 5 inhibited growth of human cervical cancer Hela cell line, melanoma A375 cell line and promyelocytic leukemia HL-60 cell line, with IC_(50) 12.00±2.08, 17.44±2.11, and 13.95±5.74 μmol/L, respectively.

Bioactive A-ring rearranged limonoids from the root barks of Walsura robusta

Screening active natural products, rapid identification, and accurate isolation are of great important for modern natural lead compounds discovery1. We hereby reported the isolation of seven new neotecleanin-type limonoids(1–7), seven new limonoids with 5-oxatricyclo[5.4.0.11,4]hendecane ring system(8–14), and two new precursors(15–16) together with four known limonoids(17–20) from the root barks of Walsura robusta. Their structures, including their absolute configurations, were elucidated based on analyses of HR-ESI-MS, 1D/2D NMR, ECD spectrum calculations and singlecrystal X-ray diffraction techniques. Compounds 2, 8, 9, 11, 13, 14, 18 showed significant anti-inflammatory activities in LPS-induced RAW 264.7 cell line, BV2 microglial cells, and Propionibacterium acnes-stimulated THP-1 human monocytic cells. Walrobsin M(11) exhibited anti-inflammatory activity with IC50 value of 7.9670.36 μmol/L, and down-regulated phosphorylation levels of ERK and p38 in a dose-dependent manner.

Lactam Triterpenoids from the Bark of Toona sinensis

Three new limonoid-type triterpenoids,namely toonasins A–C(1–3)with a rare lactam E ring,along with six known compounds(4–9)were isolated from the barks of Toona sinensis.The structures of new compounds were elucidated by interpretation of spectroscopic data,and the relative configuration of compound 1 was further characterized by X-ray crystallographic analyses.The isolated compounds were evaluated for their cytotoxic activities against five human tumor cell lines(HL-60,SMMC-7721,A-549,MCF-7 and SW480),and compounds 3 and 5 showed weak cytotoxicities.

New triterpenoids from the kernels of Azadirachta indica

Three new limonoids(1-3)and a new intact triterpenoid(4),along with three known constituents(5-7),were isolated from the dried kernels(after extracting azadirachtin)of Azadirachta indica.The structures of the new compounds 1-benzoyl-3-deacetyl-1-detigloyl salannin(1),7-tigloyl-12-oxo vilasini(2),azadiralactone(3)and azadirahemiacetal(4)were elucidated by means of spectroscopic analysis.The cytotoxities of these isolated constituents were assayed.