Five previously undescribed compounds from Ajuga lupulina Maxim. and their in vitro activities

A new biflavone (philonotisflavone-3'''-methyl ether), three diterpenes (lupulin G, lupulin H, lupulin I), a new ecdysteroid (ajugasterone E), and four known compounds were isolated from the whole plant of Ajuga lupulina Maxim. Their structures were determined by spectroscopic analysis, including MS, NMR and ECD spectral data. Compounds 1-3 has DPPH radical scavenging ability, and compound 1 has stronger activity than vitamin C. Compounds 2, 3, 7 and 8 have potential cytotoxic activity against Hela, with IC50 values less than 20.0 μM. Abietane diterpenes 2, 3, 7 and 8 are also found to have NO inhibitory effects with IC50 values less than 40.0 μM.

Development of AKR1B10 inhibitors from Ajuga nipponensis based on diseases and targets

Ten compounds (1-10) including one new neoclerodane diterpenoid (1) and nine known compounds were isolated from the whole plants of Ajuga nipponensis. Their structures were established by performing detailed analysis of NMR, the structure of 1 was determined using HRESIMS, 1D and 2D NMR, UV, and IR. Compounds 1 and 4-10 were isolated from Ajuga nipponensis for the first time. And it was the first time to report compounds 9 and 10 as natural products. Based on network pharmacology methods, 45 key targets were selected, which were compounds mapping to diseases. And compounds 2, 3, 7, and a (ajugacumbin B) exhibited excellent AKR1B10 inhibitory activities, with IC50 values of 53.05 ± 0.75, 87.22 ± 0.85, 61.85 ± 0.66, and 85.19±1.02 nM respectively, with Epalrestat used as the positive control (82.09 ± 1.62 nM). Additionally, the interaction between active compounds and AKR1B10 had been discussed according to the molecular docking results. Ultimately, the analysis of GO and KEGG enrichment indicated that the key signaling pathway of the active compounds may be related to prostate cancer. Our study results demonstrate the hypoglycemic and anti-tumor properties of A. nipponensis for the first time, and provide a comprehensive understanding of its application in traditional medicine. Furthermore, this article establishes a reference for further research on the optimized experimental design of novel AKR1B10 inhibitors.

Antifeedant, cytotoxic, and anti-inflammatory neo-clerodane diterpenoids in the peltate glandular trichomes and fresh leaves of Ajuga forrestii

The Lamiaceae plant Ajuga forrestii Diels is a traditional Chinese herbal medicine with abundant glandular trichomes (GTs), but their chemistry and biological functions remain uninvestigated. Here, a panel of six highly functionalized neo-clerodane diterpenoids was localized to the peltate GTs of A. forrestii using laser microdissection coupled with HPLC analysis, indicating that the GTs of A. forrestii are an excellent material for the elucidation of the yet unclear biosynthetic pathway of natural neo-clerodane diterpenoids. In addition, four undescribed neo-clerodane diterpenoids with an acyclic C-9 side chain including two pairs of 1:1 mixture of inseparable diastereomers, ajuforrestins D-G, were isolated from the fresh leaves of A. forrestii together with six known compounds. The structures of the undescribed compounds were elucidated by spectroscopic (including 1D and 2D NMR and HR-ESI-MS) analyses. Biological assays indicated that the major GT compound ajugacumbin B and undescribed ajuforrestins D/E showed antifeedant activity against Helicoverpa armigera, suggesting that neo-clerodanes in A. forrestii should be involved in plant defence against insects. Moreover, the abietane diterpenoid ajuforrestin B exhibited significant anti-inflammatory activity on the secretion of interleukin-2 (IL-2) and cytotoxicity against three cancer cell lines, NCI-H1975, HepG2 and MCF-7, suggesting that ajuforrestin B could positively contribute to the therapeutic effects of this traditional Chinese medicine.

Anti-inflammatory neo-Clerodane Diterpenoids from Ajuga pantantha

Eight new neo-clerodane diterpenoids (1-8) were acquired from the aerial parts of Ajuga pantantha. Spectroscopic data analysis permitted the definition of their structures, and experimental and calculated electronic circular dichroism data were used to define their absolute configurations. Compounds 2 and 4-8 were found to have NO inhibitory effects with IC₅₀ values of 20.2, 45.5, 34.0, 27.0, 45.0, and 25.8 μM, respectively. The more potent compounds 2, 6, and 8 were analyzed to establish their anti-inflammatory mechanism, including regulation of the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins as well as their binding interactions with the two proteins.

Isolation and Identification of Neo-Clerodane Diterpenes from Ajuga Nipponensis Makino

An extract of the aerial parts of Ajuga nipponensis Makino was examined by HPLC for neo-clerodane diterpenes. The suitability of reversed-phase HPLC for the semi-preparative fractionation of this extract was explored, resulting in the isolation of two new neo-clerodane diterpenes, which we have named ajuganipponin A, (12S)-1β,6α,19-triacetoxy-4α,18-epoxy-12-tigloyl-neo-clerod-13-en-15,16-olide (AJNP A, 1), and ajuganipponin B, (12S)-6α,19-diacetoxy-4α,18-epoxy-12-tigloyl-neo-clerod-13-en-15,16-olide (AJNP B, 6). In addition, ajugamarins A2 and F4, ajugamacrin B, ajugacumbin A and ajugatakasin A, were newly isolated compounds from A. nipponensis, along with the previously reported ajugamarins A1, B2 and L2 (ajugacumbin B). The structures of all the isolated compounds were unambiguously elucidated based on extensive NMR spectral studies (one and two-dimensional experiments) and their reversed-phase chromatographic behavior was established. The antifeedant activity of the isolated diterpenes against Spodoptera littoralis is also reported here.

Neo-clerodane diterpenes and phytoecdysteroids from Ajuga decumbens Thunb. and evaluation of their effects on cytotoxic, superoxide anion generation and elastase release in vitro

Five novel compounds, including four neoclerodane diterpenoids, named ajugacumbins KN (1-4) along with a phytoecdysterone, named ajugacetalsterone E (5), were isolated from the whole herbs of Ajuga decumbens (Labiatae). Their structures were elucidated on the basis of detailed spectroscopic analysis including IR, HRESIMS, CD, 1D and 2D NMR spectroscopic experiments. Compounds 1-5 were evaluated for their cytotoxic activities and the effects on superoxide anion generation and elastase release in FMLP/CB-induced human neutrophils.

Chemical and pharmacological research on the plants from genus Ajuga

The genus

neo-Clerodane Diterpenoids from Ajuga macrosperma var. breviflora

Six new naturally occurring ajugarin-like neo-clerodane diterpenoids, ajugaflorins A-F, along with six known compounds [the parent ajugarin I, ajugalides B and C, ajugamarin F4, ajugamacrin E, and ajugatakasin B] were isolated from A. macrosperma var. breviflora. The structures were elucidated by extensive NMR spectroscopic and MS analyses and comparison with data previously reported.

Bioactive neo-clerodane diterpenoids from the whole plants of Ajuga ciliata Bunge

Ten new neo-clerodane diterpenes, ajugaciliatins A-J (1-5, 8-12), along with 17 known analogues (6, 7, 13-27) were isolated from the whole plants of Ajuga ciliata Bunge. Their structures were elucidated by spectroscopic data analysis (IR, ESIMS, HRESIMS, 1D and 2D NMR), and the configuration of 1 was confirmed by X-ray crystallography. All of the compounds were assessed for neuroprotective effects against MPP(+)-induced neuronal cell death in dopaminergic neuroblastoma SH-SY5Y cells. Compounds 2, 6, 7, 9, 10, 15-17, 19, and 20 exhibited moderate neuroprotective effects.

A new phytoecdysteroid from Ajuga taiwanensis

A new phytoecdysteroid, namely ajugalide-E (1), together with twenty five known compounds were isolated from Ajuga taiwanensis collected from Tainan, Taiwan. Their structures were determined by spectral analysis including high resolution one- and two-dimensional NMR spectroscopy.

Neoclerodane Diterpenoids from Ajuga taiwanensis

Phytochemical investigation of Ajuga taiwanensis resulted in the isolation of seven neoclerodane diterpenes, four of which ajugalide-A (1), -B (2), -C (3), and -D (4), are new and the remaining three are known diterpenes, ajugamacrin B (5), ajugapantin A (6), and ajugamarin C1 (7). Their structures were elucidated in spectral and chemical transformation studies.

NMR shift data of neo-clerodane diterpenes from the genus Ajuga

The complete assignment of the NMR spectra of ajugarin I and ajugareptansin, as models for other neo-clerodane diterpenoids isolated from the genus Ajuga, is reported in order to improve their usefulness as reference compounds. Conflicting NMR shift data for some members of this group are discussed, and plausible reassignments are proposed [i.e. the identity of ajugacumbin C and ajugamarin A2; the revision of ajugacumbin D as 12-hydroxyajugacumbin A, and of ajugacumbin E as 12-hydroxy-1-(3-hydroxy-2-methylenebutanoyloxy)ajugarin I] in order to provide a unified basis for future use.