Chemical composition and biological activities of essential oil from Grewia bulot leaves

This study focused on the chemical composition and biological activities of the essential oil derived from Grewia bulot, a plant species known for its medicinal properties. The analysis of Grewia bulot essential oil revealed the presence of 78 constituents. The major compounds were α-cadinol (13.5%), 1,8-cineole (12.7%), 1,10-di-epi-cubenol (9.8%), epi-α-cadinol (6.7%), (E,E)-α-farnesene (5.9%), (E)-citral (4.0%), selin-11-en-4-α-ol (4.0%), citronellol isobutanoate (3.9%), and geranic acid (3.7%). The essential oil exhibited promising antioxidant potential with an IC50 value of 452.65 ± 28.40 µg/mL in DPPH model. This oil did not show NO production inhibitory effect in RAW 264.7 cells. In addition, the essential oil exhibited significant cytotoxicity against KB, Hep-G2, MCF-7, and SK-LU-1 cancer cell lines, with IC50 values ranging from 44.04 ± 1.47 to 74.20 ± 3.71 μg/mL.

Microgrewiapine C: Asymmetric Synthesis, Spectroscopic Data, and Configuration Assignment

The first asymmetric synthesis of microgrewiapine C, a piperidine alkaloid isolated from Microcos paniculata, is reported. This synthesis prompted correction of the 1H and 13C NMR data for the natural sample of the alkaloid, which was achieved by reanalysis of the original spectra. The corrected data for the natural product were found to be identical to those of the synthetic sample prepared herein, thus confirming the structural and relative configurational assignment of microgrewiapine C. Although comparison of specific rotation values indicates that the (1R,2S,3S,6S) absolute configuration should be assigned to the alkaloid, consideration of potential common biosynthetic origins of microgrewiapine C and congeners suggests that further phytochemical investigations are warranted.

Angiogenesis-Inhibitory Piperidine Alkaloids from the Leaves of Microcos paniculata

Eight new 2,6-disubstituted piperidin-3-ol alkaloids (1-8), featuring a C₁₀ unsaturated alkyl side chain, together with three previously reported analogues (9-11) were isolated from the leaves of medicinal plant Microcos paniculata. Their structures and absolute configurations were elucidated unambiguously by means of 1D and 2D NMR spectroscopic data analysis, modified Mosher's method, Snatzke's method, and quantum chemical electronic circular dichroism (ECD) calculations, as well as single-crystal X-ray crystallography. The isolates were evaluated for their antiangiogenic effects on human umbilical vein endothelial cells (HUVECs). Compound 2 displayed an inhibitory effect on tube formation of HUVECs in a concentration-dependent manner.

Natural Alkaloids and Diabetes Mellitus: A Review

BACKGROUND

The use of herbal therapies for treatment and management of diabetes mellitus and complications associated with this chronic condition is increasing. Plants contain a bounty of phytochemicals that have been proven to be protective by reducing the risk of various ailments and diseases, including alkaloids. Moreover, alkaloids are known to be among the oldest natural products used by humans for highlighting drugs that play crucial roles as therapeutic agents. The reason for this expanding interest and uses of alkaloids as a part of plant natural compounds-based treatments is that a significant proportion of diabetic patients do not respond very well to conventional therapeutic medication. Furthermore, other explanations to this fact are the cost of medication, side-effects, accessibility, and availability of health facilities and drugs and the inefficiency of these medicines in certain cases.

OBJECTIVE

In this study we aimed to review the literature on the valuable effects of herbs and plants and their isolated alkaloids compounds as medication for management of diabetes, a prevalent risk factor for several other disorders and illnesses.

METHODS

In the current review, PubMed, ScienceDirect, Springer and google scholar databases were used and the criterion for inclusion was based on the following keywords and phrases: diabetes, hyperglycemia, complications of diabetes, alkaloids, antidiabetic alkaloids, hypoglycemic alkaloids, alkaloids and complications of diabetes mellitus, mechanisms of action and alkaloids.

RESULTS

In the current review, we demonstrate that alkaloids in the form of extracts and isolated molecules obtained from a large variety of species demonstrated their efficiency for improving raises in blood glucose either in animal models via experimental studies or in human subjects via clinical trials. Medicinal species as chillies (Capsicum annuum), turmeric (Curcuma longa), barberry (Berberis vulgaris) and cress (Lepidium sativum) are among the most common and therapeutic plants used for controlling diabetes that were the subject of several experimental and clinical investigations. Whereas, isolated alkaloids such as berberine, capsaicin and trigonelline have received more interest in this field. Interestingly, the therapeutic impact of alkaloids against blood glucose pathogenesis is mediated through a variety of signaling cascades and pathways, via inhibiting or stimulating diversity of systems such as inhibition of α-glucosidase enzyme, blockade of PTP- 1B, deactivation of DPP-IV, increasing insulin sensitivity and modulating the oxidative stress.

CONCLUSION

Based on the findings of the present review, alkaloids could be used as preventive and curative agents in the case of endocrine disorders, particularly diabetes and could play a promoting function for the discovery of new antidiabetic agents.

Variations of Flavone Glycosides Profile Underscore the Necessity of Quality Control of Prepared Microctis Folium Slices

Microctis Folium (MF), the dried leaves of Microcos paniculata, is widely used as a medical and food dual-purpose herb in South-east Asia and China. However, the quality control of MF is not well studied. A simple and reliable quality control method was urgently needed for its growing usage. Herein, at first, its main active components were identified by UPLC-ESI-qTOF-MS, and a representative MF flavone glycosides profile consisting of ten compounds was illustrated, which is the most detailed one up to now. Successively, using vitexin as the reference substance, a novel QAMS method with HPLC for quantification of the ten identified flavone glycosides was developed and methodologically validated. Furthermore, making use of the abovementioned QAMS method, quantitative profiling of 21 batches of prepared MF slices collected from different hospital pharmacies were performed. As a result, the total contents of ten flavone glucosides and the content of specific compound showed obvious variations. Using the ten compounds' contents dataset, the 21 batches of samples were divided into two distinct clusters by HCA. In sum, our results indicated that it was of great importance to take quality control of prepared MF slices and we presented a robust and simple method for their quantitative determination, which should be beneficial for the quality control of MF and its derived products.

An integrated strategy for rapid discovery and identification of quality markers in Guanxin Kangtai preparation using UHPLC-TOF/MS and multivariate statistical analysis

BACKGROUND

Guanxin Kangtai preparation (GXKT), consisting of Panax ginseng, Panax notoginseng and Ilex pubescens, is a new proprietary Chinese medicines under development for treating coronary heart disease. Like other Chinese medicines, the components of GXKT were complex and the bioactive compounds remained unclear.

PURPOSE

To discover bioactive compounds as quality markers (Q-markers) for better quality control of GXKT.

STUDY DESIGN

Chinese medicines was separated into fractions. The correlation between chemical information and bioactivity of these fractions were analyzed with multivariate statistical methods to discover bioactive compounds responsible for the actions of Chinese medicine.

METHOD

GXKT was separated into fractions by using high-performance liquid chromatography (HPLC). Ultra HPLC coupled with time-of-flight mass spectrometer (UHPLC-TOF/MS) was applied to detect compound information from these fractions to form a chemical database. The bioactivity of these fractions in protecting cardiomyocytes from ischemia/reperfusion injury was examined in H9c2 cells that were exposed to hypoxia followed by reoxygenation (H/R). Then, partial least square model and orthogonal projections to latent structures discriminant analysis were employed to discover bioactive compounds from the chemical database that were positively correlated with the bioactivity of GXKT fractions. Finally, the bioactivity of these compounds was confirmed by bioassay in H9c2 cells.

RESULTS

The chemical information of 120 fractions separated from GXKT was detected and extracted by UHPLC-TOF/MS, and a chemical database including 61 high abundance compounds were formed from all fractions. These fractions produced different extent of protective effect to H9c2 cell underwent H/R treatment with cell viability ranging from 33.43% to 74.91%, demonstrating the separation of bioactive compounds among different fractions. The multivariate analysis discovered 16 compounds from GXKT positively correlated with the bioactivity of GXKT. Of these compounds, 6 compounds, i.e.: ginsenoside Rg₁, Rb₁, Rh₁, Rc, ilexsaponin A₁, and chikusetsusaponin IVa were chemical identified and also confirmed for their responsibility to the action of GXKT by bioassay.

CONCLUSION

Ginsenoside Rg₁, Rb₁, Rh₁, Rc, ilexsaponin A₁, and chikusetsusaponin IVa were bioactive compounds and qualified as Q-markers for quality control of GXKT. This research provided a useful reference for the quality research of Chinese medicines.