Chemical constituents from Salacia impressifolia (Miers) A. C. Smith collected at the Amazon rainforest

The phytochemical investigation of Salacia impressifolia (Miers) A. C. Smith led to the isolations of 15 compounds, including triterpene quinonemethides, which are employed as the common characteristic constituents of the Celastraceae family. Pristimerin (9) and tingenone (12) were isolated as the main compounds in the studied tissues. Additionally, friedelane, lupane, oleanane, and ursane triterpenoids were also isolated. All of them were isolated from this plant for the first time.     

New α-Glucosidase inhibitors from the resins of Boswellia species with structure–glucosidase activity and molecular docking studies

Phytochemical investigation of the oleo-gum resins from Boswellia papyrifera afforded one new triterpene, named 3α-hydroxyurs-5:19-diene (1) together with twelve known compounds including eight triterpenoids (2–9), two diterpenoids (10 and 11) and two straight chain alkanes (12 and 13). Similarly ten more known compounds were isolated from the resin of Boswellia sacra including one triterpene (20) and nine boswellic acids (14–19 and 21–23). Herein the compound 2 was first time reporting from natural source along with complete NMR assignment, while compounds 3–11 are known, but reported for the first time from the resin of B. papyrifera. The structure elucidation was done by advance spectroscopic ¹D and ²D NMR techniques viz., ¹H, ¹³C, DEPT, HSQC, HMBC, and COSY, and NEOSY, ESI-MS and compared with the reported literature. All compounds were evaluated for their α-glucosidase inhibitory activity and as result eight of them 1, 3, 10, 11, 15, and 17–19 were found significantly active against α-glucosidase with an IC₅₀ value ranging from 15.0 ± 0.84 to 80.3 ± 2.33 µM, while 21 exhibited moderate activity with IC₅₀ of 799.9 ± 4.98 µM. Furthermore, two compounds 24 and 25 were synthesised from 16 and 17 to see the effect of carboxyl group in structural-activity relationship (SAR) study. Compounds 24 and 25 retained good α-glucosidase inhibition as compared to 16 and 17, indicating that carboxylic group play a key role in SAR. In addition, the aforementioned activity of all the active compounds was first time reported for their α-glucosidase inhibition potential. The molecular docking studies showed that all the active compounds well accommodate in the active site of the enzyme. Moreover pharmacokinetic properties of the compounds were predicted in silico, suggesting that the compounds possess drug like properties and excellent ADMET profile.     

α-Pyrones,secondary metabolites from fungus Cephalotrichum microsporum and their bioactivities

Cephalotrichum microsporum (SYP-F 7763) was a fungus isolated from the rhizosphere soil of traditional Chinese medicine Panax notoginseng. The EtOAc extract of Cephalotrichum microsporum cultivated on sterilized moistened-rice medium was separated by various chromatographic techniques, which yielded 11 metabolites (1–11) of this fungus. On the basis of the widely spectroscopic data, the chemical structures of isolated metabolites were determined, most of which were α-pyrones, including 5 compounds (4–7, and 10) unreported. In the anti-bacterial bioassay, compound 1 displayed significant inhibitory effects on three pathogenic bacteria, MR S. aureus, S. aureus, and B. cereus. α-Pyrones 2, 3, and 5–7 also displayed moderate inhibitory effects on MR S. aureus, S. aureus, and B. subtilis, which could be the major anti-bacterial constituents of Cephalotrichum microsporum. Additionally, compounds 1, 4, and 5 displayed significant cytotoxicity on five human cancer cell lines, with the IC₅₀ values < 20 μM, which are more effective than positive control 5-fluorouracil. Therefore, α-pyrones were important secondary metabolites of Cephalotrichum microsporum, which displayed anti-bacterial and anti-tumor activities.     

我国卫矛科杀虫植物研究进展

卫矛科植物由于具有独特的生物活性而受到广泛关注。作者主要综述了我国对卫矛科杀虫植物的研究进展。迄今为止,该科植物中发现的主要杀虫成分均是以二氢沉香呋喃为骨架的多元醇酯和生物碱。就杀虫活性而言,主要是对昆虫拒食作用的测定,仅对苦皮藤(Celastrus angulatus)和雷公藤(Tripterygium wilfordii)杀虫成分的毒杀、麻醉等胃毒作用的研究比较系统深入。此外,也对当前这些研究中存在的问题及前景进行了分析。     

Three new cucurbitane triterpenoids from Hemsleya penxianensis and their cytotoxic activities

Two new cucurbitane glycosides, hemslepenside A (1) and 16,25-O-diacetyl-cucurbitacin F-2-O-β-d-glucopyranoside (3), one new cucurbitacin, 16-O-acetyl-cucurbitacin F (2), along with three known cucurbitane compounds, were isolated from the roots of Hemsleya penxianensis. The structures of 1–6 were established on the basis of extensive spectroscopic and chemical methods. The isolated compounds were evaluated for their cytotoxic activities against different three human cancer cell lines, with IC₅₀ values in the low microgram range.     

Three daphnane diterpenoids from Trigonostemon xyphophylloides

Three daphnane diterpenoid trigoxyphins U–W (1–3), together with two known daphnane diterpenoids (4 and 5) were isolated from Trigonostemon xyphophylloides. Their structures were elucidated by spectroscopic analysis. Compound 3 showed modest cytotoxicity against BEL-7402, SPCA-1 and SGC-7901 cancer cell lines.