Seven new 2-(2-phenethyl)chromone derivatives from agarwood of Aquilaria walla.

Two rare flavonoid-2-(2-phenylethyl)chromones and five new dimeric 2-(2-phenylethyl)chromones were isolated from ethanol extract of agarwood of Aquilaria walla by LC-MS-guided fractionation procedure. Their structures were established based on extensive spectroscopic methods including HRESIMS, 1D and 2D NMR, as well as by comparison with the literature. Compound 1 showed cytotoxic activity against five human cancer cell lines with IC50 values ranging from 13.40 to 28.96 µM with cisplatin as the positive control.

LC-MS-guided isolation of 2-(2-phenylethyl)chromone dimers from red soil agarwood of Aquilaria crassna.

Six new 2-(2-phenylethyl)chromone dimers (1-6) were isolated from ethyl ether extract of red soil agarwood of Aquilaria crassna from Vietnam by LC-MS-guided fractionation procedure. Their structures were unambiguously elucidated based on HRESIMS, 1D and 2D NMR spectra. The absolute configuration of 2-(2-phenylethyl)chromone dimers was determined by comparison of the experimental and computed ECD spectra. Compound 6 displayed cytotoxicity against the human myeloid leukemia cell line (K562) with an IC50 value of 39.49 µM.

[A new cytotoxic isoflavane from Dalbergiae Odoriferae Lignum].

Fourteen compounds were isolated from the ethanol extract of Dalbergiae Odoriferae Lignum by various chromatographic techniques, including column chromatographies on silica gel, Sephadex LH-20 and semi-preparative HPLC. Their structures were determined by spectroscopic techniques as S-3'-hydroxy-7,2',4'-trimethoxyisoxane(1), 2-(2',4'-dimethoxyphenyl)-6-hydroxybenzofuran(2), 2-(2'-hydroxy-4'-methoxyphenyl)-6-methoxybenzofuran(3), 7,2',4'-trimethoxydihydroisoflavone(4), sativanone(5), 3,9-dimethoxy-6H-benzofuro[3,2-c]chromen-6-one(6),(6 aS,11 aS)-homopterocarpin(7),(6 aS,11 aS)-8-hydroxy-3,9-dimethoxypterocarpan(8),(6 aS,11 aS)-3,8,9-trimethoxypterocarpan(9), isodalbergin(10), isoliquiritigenin(11), butein(12), butin(13) and 3,7,4'-trihydroxyflavone(14). Among them, compound 1 was a new compound, while 2 and 3 were new natural products, 6, 8, 9 and 14 were isolated for the first time from Dalbergiae Odoriferae Lignum. Compounds 1-14 were tested for their cytotoxic activity against human hepatoma cell line BEL-7402, human gastric cancer cell line SCG-7901, human lung cancer cell line A549, human chronic myeloid leukemia cell line K562 and HeLa human cervical cancer cellline by MTT method. Compound 1 exhibited significant cytotoxicity with IC_(50) values ranging from 2.85 to 11.62 µg·mL~(-1). In addition, 2, 11 and 12 showed weak cytotoxic activities.

Four new guaiane sesquiterpenoids from agarwood of Aquilaria filaria.

Six 8,12-epoxyguaiane sesquiterpenes (1-6), together with two known 2-(2-phenylethyl)chromone derivatives (7-8) were isolated from agarwood originating from Aquilaria filaria. Their structures were established by spectroscopic methods including IR, HRESIMS, 1D, and 2D NMR, and comparison with the published data. The absolute configuration of compound 1 was unambiguously determined by quantum chemical calculation of the electronic circular dichroism (ECD) spectrum. All compounds were tested for their α-glucosidase inhibitory activity and cytotoxicity. Compound 5 showed significant α-glucosidase inhibitory activity with IC50 value of 253.2 ±â€¯9.7 µM (Acarbose, 743. 4 ±â€¯3.3 µM). Compounds 2-4 displayed weak cytotoxicity against K562 tumor cell lines.

[A new eudesmane type sesquiterpene from cultivated Clerodendranthus spicatus in Hainan].

Six compounds were isolated from the aerial part of cultivated Clerodendranthus spicatus in Hainan with various chromatographic techniques,and their structures were determined as:1-dehydroxy-1-oxo-rupestrinol(1),N-trans-feruloyltyramine(2),methyl 3,4-dihydroxyphenyllactate(3),caffein acid(4),methyl caffeate(5) and ethyl caffeate(6),via analysis of physicochemical properties and spectroscopic evidence.Compound 1 was a new compound,while compounds 2 and 3 were isolated from C.spicatus for the first time.Biological activity results showed that compounds 2-4 exhibited α-glucosidase inhibitory activity with different inhibition ratio.

Three new flavanoids from artificially induced dragon's blood of Dracaena cambodiana.

Three new flavanoids, (2R)-7,4'-dihydroxy-8-methylflavan (1), (2R)-7,4'-dihydroxy-6-methylflavan (2), and (3R)-7,3',4'-trihydroxyhomoisoflavan (3), together with seven known compounds (4-10), were isolated from artificially induced dragon's blood of Dracaena cambodiana, and their structures were determined based on HR-ESI-MS and extensive spectroscopic techniques (UV, IR, 1D-, and 2D-NMR). Compound 2 exhibited weak cytotoxicity against BEL-7402 cells line with the IC50 value of 39.2 µM. In addition, compound 3 showed significant acetylcholinesterase (AChE) inhibitory activity.

2-(2-Phenylethyl)chromone Derivatives of Agarwood Originating from Gyrinops salicifolia.

Three new2-(2-phenylethyl)chromone derivatives (1-3) and a new2-(2-phenylethenyl)chromone derivative (4), together with two known 2-(2-phenylethyl)chromone derivatives (5-6), were isolated from agarwood originating from Gyrinops salicifolia Ridl. The structures of compounds 1-4 were elucidated by comprehensive spectroscopic techniques (UV, IR, 1D and 2D-NMR) and MS analysis, as well as by comparison with the literature. Compounds 1, 2, and 5 showed moderate cytotoxicity against human tumor K562, BEL-7402, and SGC-7901 cell lines with IC50 values of 5.76 to 20.1 µM.

Sesquiterpenes of agarwood from Gyrinops salicifolia.

Six new sesquiterpenoids (1-6) and six known sesquiterpenoids (7-12) were isolated from agarwood originated from Gyrinops salicifolia Ridl. Most of them gave off aromatic odor, and all the compounds were isolated from this genus for the first time. The structures of 1-6 were elucidated by spectroscopic techniques (UV, IR, 1D and 2D NMR) and MS analysis, as well as by comparison with literature data. Compounds 1, 6 and 11-12 showed moderate acetylcholinesterase (AChE) inhibitory activity.

Two new phragmalin-type limonoids from Chukrasia tabularis and their α-glucosidase inhibitory activity.

Phytochemical investigation on the stems of C. tabularis (Meliaceae) led to the isolation of two new phragmalin-type limonoids, named tabularisins S and T (1-2), along with five known ones (3-7). The structures of the new limonoids were established by spectroscopic methods including UV, IR, HRESIMS, and 1D and 2D NMR. All the compounds were evaluated for α-glucosidase inhibitory activity in vitro. Compounds 2 and 3 exhibited significant inhibitory activity against α-glucosidase with IC50 values of 0.15 and 0.03 mM, respectively (acarbose as positive control, IC50 0.95 mM).

2-(2-Phenylethyl)chromone derivatives in artificial agarwood from Aquilaria sinensis.

Seven new 2-(2-phenylethyl)chromone derivatives (1-7) including a chlorinated one (4), together with eight known ones (8-15), were isolated from the EtOAc extract of artificial agarwood originating from Aquilaria sinensis (Lour.) Gilg. All structures including the absolute configurations were unambiguously elucidated by spectroscopic (NMR, UV, IR, MS) methods, Mosher's method, and comparison with reported data in the literatures. Among those, compounds 8, 12, and 14 exhibited significant inhibition against α-glucosidase in vitro with IC50 values of 0.15, 0.05, and 0.09 mM, respectively (with acarbose as the positive control; IC50: 0.98 mM). In addition, compounds 3, 9, 11, and 14 showed weak inhibitory activity against AChE; and compounds 12 and 13 displayed weak cytotoxicity against human gastric cell line (SGC-7901) among three types of tested human cancer cell lines (BEL-7402, K562, and SGC-7901).

A new apotirucallane-type triterpenoid from Atalantia buxifolia.

A new triterpenoid (1) with apotirucallane skeleton was isolated from the ethanol extract of the roots of Atalantia buxifolia (Poir.) Oliv. The complete structural assignment of the new compound was elucidated by a combination of 1D, 2D NMR (HMQC, HMBC, COSY, and NOESY), and HR-ESI-MS analysis. Moreover, this new compound was evaluated in vitro for its cytotoxic, antimicrobial and enzymes inhibitory activities.