Cui-Juan Gai

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, Moshers 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).

Metabolites with Insecticidal Activity from Aspergillus fumigatus JRJ111048 Isolated from Mangrove Plant Acrostichum specioum Endemic to Hainan Island

Fungi residing in mangroves are considered to be a bank of novel bioactive natural products. In the screening for bioactive metabolites from mangrove-derived fungi, the ethyl acetate extract of the fermentation broth of Aspergillus fumigatus JRJ111048, a fungus isolated from the leaves of the mangrove plant Acrostichum specioum endemic to Hainan island, was found to possess insecticidal activity against Spodoptera litura. Bioactivity-guided isolation lead to the discovery of seven metabolites 1–7, including one new anhydride derivative aspergide (1), one new lipid amide 11-methyl-11-hydroxyldodecanoic acid amide (2), and five known compounds; α-ethyl glucoside (3), spiculisporic acid B (4), spiculisporic acid C (5), spiculisporic acid (6), and secospiculisporic acid B (7). Their structures were established by NMR spectroscopic and MS analyses, and by comparison of previously reported data. Insecticidal activity against S. litura and antifungal activity of these compounds were investigated. As a result, the new compound 1 showed potent insecticidal activity against newly hatched larvae of S. litura, and compound 4 displayed weak antifungal activity against Candida albicans.

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.

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

Three new 2-(2-phenylethyl)chromone derivatives (1–3) and a new 2-(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.

New Phragmalin-Type Limonoids from Chukrasia tabularis and Their α-Glucosidase Inhibitory Activity

Phytochemical investigation on the stems of C. tabularis led to the isolation of five new phragmalin-type limonoids and six known ones. The structures of the new compounds 1–5, named chukbularisins A–E, were elucidated by spectroscopic techniques (IR, HRESIMS, 1D and 2D NMR) and comparisons with published data. All the compounds were evaluated for in vitro α-glucosidase inhibitory activity. Compounds 2, 3, 4, 5, and 8 exhibited inhibitory activity against α-glucosidase with IC50 values of 0.06 ± 0.008, 0.04 ± 0.002, 0.52 ± 0.039, 1.09 ± 0.040, and 0.20 ± 0.057 mM, respectively (using acarbose as positive control, IC50 0.95 ± 0.092 mM).

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

Abstract 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).

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.

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

Abstract 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.