Structurally diverse isoquinoline alkaloids from the barks of Alangium salviifolium (L. f.) Wangerin and their cytotoxicity.

Eleven undescribed isoquinoline alkaloids (1-8, 14, 15, and 24), along with 19 analogues (9-13, 16-23, and 25-30) were isolated from the barks of Alangium salviifolium. The structures of the undescribed compounds were elucidated through the analysis of their HR-ESI-MS, 1D and 2D NMR, IR, UV, and X-ray diffraction. The absolute configuration of 8 was established via the ECD calculation. Notably, compounds 1/2 and 3/4 were two pairs of C-14 epimers. The isolated alkaloids were evaluated for their cytotoxicity against various cancer cell lines, including SGC-7901, HeLa, K562, A549, BEL-7402, HepG2, and B16, ß-carboline-benzoquinolizidine (14-22) and cepheline-type (24-28) alkaloids exhibited remarkable cytotoxicity, with IC50 values ranging from 0.01 to 48.12 µM. Remarkably, compounds 17 and 21 demonstrated greater cytotoxicity than the positive control doxorubicin hydrochloride. Furthermore, a significant proportion of these bioactive alkaloids possess a C-1' epimer configuration. The exploration of their structure-activity relationship holds promise for directing future investigations into alkaloids derived from Alangium, potentially leading to novel insights and therapeutic advancements.

[Chemical constituents with α-glucosidase inhibitory activities from seeds of Morinda citrifolia (Noni)].

The present study investigated the chemical constituents and inhibitory activities against α-glucosidase from the seeds of Morinda citrifolia(Noni) by the chromatographic technique and semi-preparative HPLC.Fifteen compounds were isolated from the ethyl acetate extract of the seeds, and their structures were identified on the basis of physiochemical characteristics and spectroscopic data as(9S,2E,4Z,7Z)-9-hydroxydeca-2,4,7-trienoic acid(1), azelaic acid(2), scopoletin(3), ursolic acid(4), quercetin(5), cyclo-(L-Leu-L-Ile)(6), cyclo-(L-Phe-L-Ile)(7), cyclo-(L-Phe-L-Val)(8), cyclo-(L-Leu-L-Val)(9), cyclo-(L-Phe-L-Leu)(10), caffeic acid(11), 3,4-dihydroxycinnamaldehyde(12), p-hydroxybenzoic acid(13), p-hydroxy-cinnamic acid(14), and p-hydroxyphenethyl alcohol(15).Among them, compound 1 was a new fatty acid and compounds 7-10 and 12 were isolated from Morinda plant in the Rubiaceae family for the first time.Compounds 1, 2 and 4-15 were isolated from the seeds of M.citrifolia(Noni) for the first time.All isolated compounds were evaluated for the inhibitory activities against α-glucosidase and compounds 3-5 showed potential inhibitory activity with IC_(50) values of 160, 133, and 120 µmol·L~(-1), respectively.

Callnudoids A-H: Highly modified labdane diterpenoids with anti-inflammation from the leaves of Callicarpa nudiflora.

Eight undescribed 3,4-seco-norlabdane diterpenoids, callnudoids A-H, as well as two known analogues were isolated from the leaves of Callicarpa nudiflora. The structures were elucidated using spectroscopic methods and were compared with published NMR spectroscopic data. The absolute configurations of callnudoids D and E were defined based on ECD data or single-crystal X-ray diffraction. Callnudoids A-C are the highly modified labdane diterpenoids featuring rearranged 3,4-seco-ring and the formation of an undescribed cyclohexene moiety via C2-C18 cyclization. They only contain 15 carbon atoms on the carbon skeleton. Callnudoid D represents the unusual 3,4-seco-15,16-norlabdane diterpenoid with C13-C17 cyclization, and a putative biosynthesis pathway for callnudoids A, B, D, and E was proposed. All compounds were evaluated for their anti-inflammatory activities by inhibiting the lipopolysaccharide (LPS)-induced nitric oxide (NO) released in RAW264.7 cells; callnudoids A-E and H, and methylcallicarpate obviously inhibited pro-inflammatory cytokines TNF-α and IL-1ß in a dose-dependent manner.

New alkaloids from the noni juice with potential α-glucosidase inhibitory activity.

Four new alkaloids, nonialkaloids A-D (1-4) and six known analogues (5-10) were isolated from the noni juice. Among the new compounds, 1 and 2 are indole alkaloids with a seven-membered fused N-heterocyclic ring, 3 and 4 are quaternary ammonium derivatives. The structures were elucidated by extensive NMR and MS analysis, while the absolute configurations of the stereogenic carbons were established based on quantum-chemical electronic circular dichroism calculations or the modified Mosher's method. All the isolates were tested for α-glucosidase inhibitory activities. Compounds 1 and 3 displayed potent inhibitory activity against α-glucosidase with the IC50 values of 413.7 and 364.4 µM, respectively.

Bioactive cyclohexene derivatives from a mangrove-derived fungus Cladosporium sp. JJM22.

Four new cyclohexene derivatives cladoscyclitols A-D (1-4) and one new ribofuranose phenol derivative 4-O-α-D-ribofuranose-2-pentyl-3-phemethylol (5) were obtained from the EtOAC extract of the mangrove-derived endophytic fungus Cladosporium sp. JJM22. The structures were elucidated by extensive NMR and MS analysis, while the absolute configurations of the stereogenic carbons were established based on quantum-chemical electronic circular dichroism calculations or comparison of the optical rotations with those of related compounds. Compounds 2 and 5 displayed potent inhibitory activity against α-glucosidase with the IC50 values of 2.95 and 2.05 µM, respectively.

New 2-(2-phenylethyl)chromone derivatives from agarwood and their inhibitory effects on tumor cells.

Two new chromone derivatives, 7-hydroxy-2-[2-(3'-methoxy-4'-hydroxyphenyl)-ethyl]chromone (1), and 6,7-dimethoxy-2-[2-(3'-hydroxyphenyl)-ethyl]chromone (2) were isolated from the EtOH extract of agarwood of Aquilaria sinensis, together with eleven known analogues. Their structures were established by detailed HR-ESIMS, 1D and 2D NMR spectroscopic analysis, as well as comparison with the literature data. Selected the isolates (1, 2, 4-8, 10, 11) were tested for their antitumor activities against SMMC-7721, MGC-803 and OV-90 cell lines using the MTT method with cisplatin and paclitaxel as the positive control. All the tested compounds showed weak cytotoxic activities with IC50 values ranged from 18.82 to 37.95 µg/ml.

[Anti-inflammatory sesquiterpenes from agarwood produced via whole-tree agarwood-inducing technique of Aquilaria sinensis].

The present study is to investigate the chemical constituents and anti-inflammation of agarwood produced via whole-tree agarwood-inducing technique( Agar-Wit) from Aquilaria sinensis by column chromatographic technique and semi-preparation HPLC.Eleven sesquiterpenes were isolated from the agarwood produced by Agar-Wit,and their structures were identified on the basis of physiochemical characteristics and spectroscopic data analysis as baimuxinol( 1),5α,7α( H)-eudesm-11( 13)-en-4α-ol( 2),( 7 S,9 S,10 S)-( +)-9-hydroxy-selina-4,11-dien-14-al( 3),petafolia A( 4),7( 11)-eremophilen-8-one( 5),neopetasane( 6),petafolia B( 7),11-hydroxy-valenc-1( 10)-en-2-one( 8),( 4αß,7ß,8αß)-3,4,4α,5,6,7,8,8α-octahydro-7-[1-( hydroxymethyl) ethenyl]-4α-methylnaphthalene-1-carboxaldehyde( 9),12-hydroxy-4( 5),11( 13)-eudesmadien-15-al( 10),and( 4 R,5 R,7 S,9 S,10 S)-(-)-eudesma-11( 13)-en-4,9-diol( 11). Among them,compound 1 was a new natural product,and this is the first time to report its13 CNMR spectroscopic data. Compounds 4,9 and 10 were reported from Aquilaria for the first time,and all the compounds are firstly isolated by Agar-Wit from A. sinensis. The anti-inflammatory activity of RAW264. 7 cells with lipopolysaccharide-induced was evaluated.As a result,1,4 and 9 showed potential anti-inflammatory activities with IC50 values( 2. 5±0. 35),( 3. 2±0. 2),( 4. 3±0. 56) µmol·L-1,respectively. This work provided scientific foundation for quality evaluation of the agarwood produced by Agar-Wit.

3,4- seco-Norclerodane Diterpenoids from the Roots of Polyalthia laui.

Ten new clerodane diterpenoids, polylauioids A-J (1-10), and five known analogues (11-15) were isolated from the roots of Polyalthia laui. Among the new compounds, 3 and 8 are artifacts. The structures were elucidated using spectroscopic methods and by comparison with published NMR spectroscopic data. The absolute configurations of 4, 5, and 7 were defined based on single-crystal X-ray diffraction and electronic circular dichroism data. Compounds 1 and 2 represent the first examples of rearranged 3,4- seco-norclerodane diterpenoids, and a putative biosynthesis pathway for these compounds is proposed. Compounds 1, 4, 6, 7, 9, and 10 showed anti-HIV activities with EC50 values ranging from 12.2 to 35.2 µM.

A new norsesquiterpene from the roots of Polyalthia laui.

One new norsesquiterpene polyalone A (1), and one new natural product 9-keto-cyclocolorenone (2), along with three known analogues (3-5) were isolated from the roots of Polyalthia laui. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. All compounds were evaluated for their cytotoxic activities and antibacterial activities.

New phenylpropanoid and 6H-dibenzo[b,d]pyran-6-one derivatives from the stems of Dasymaschalon rostratum.

Three new phenylpropanoid derivatives, dasymaroacid A (1), dasymaroesters B and C (2 and 3), and one new polyoxygenated 6H-dibenzo[b,d]pyran-6-one derivative dasymarolactone D (4), together with seven known compounds (5-11), were isolated from the stems of Dasymaschalon rostratum Merr. Compounds 1 and 2 are unusual phenylpropanoid derivatives with a polymethyl substituted cyclopentene conjugated diketone as a substituent, and 3 is a unique cinnamic acid detective with a polymethyl substituted cyclohexene conjugated triketone as a substituent. Their structures were elucidated by extensive spectroscopic methods and chemical method, and 4 was further confirmed by the single crystal X-ray diffraction method. Compounds 1-4 and 7 showed weak anti-HIV-1 activities with EC50 values ranged from 16.44 to 25.91µM.

New clerodane diterpenoids from the roots of Polyalthia laui.

Five new clerodane diterpenoids, polylauiester A (1), (4→2)-abeo-2,13-diformyl-cleroda-2,12E-dien-14-oic acid (2) and polylauiamides B-D (3-5), together with 11 known clerodane diterpenoids (6-16), were isolated from the roots of Polyalthia laui. Among them, polylauiester A (1) represents the first example of a novel norclerodane diterpenoid only containing 17 carbon atoms on the carbon skeleton, and polylauiamide B (3) is an unusual diterpenoid with a p-substituted benzene ring as a substituent. Their structures were elucidated by extensive spectroscopic methods, and the relative configuration of polylauiamide B (3) was further confirmed by the single crystal X-ray diffraction method. Biological evaluation of new compounds against human Hela, MCF-7 and A549 human cancer cell lines showed that all compounds displayed weak cytotoxicities against various human cancer cell lines in the range of IC50 at 25.01-39.31µM.