A new norsesquiterpene from the roots of Polyalthia laui

A New Clerodane from the Leaves of Croton krabas and Its Cholinesterase Inhibitory Activities

Chromatographic separation of the leaves of Croton krabas resulted in the isolation of one new clerodane, crotoeurin D (1), along with two known compounds, 6S-crotoeurin C (2) and blumenol A (3). Their structures were determined based on extensive nuclear magnetic resonance spectroscopic data analysis and mass spectrometry. The absolute configuration of the new clerodane was assigned by nuclear overhauser effect spectroscopy correlations and electronic circular dichroism calculations. Compound 1 exhibited significant acetylcholinesterase and butyrylcholinesterase inhibitory activities. Moreover, the binding modes of 1 revealed that its structure formed strong hydrogen bonds and hydrophobic interactions with the active sites of both enzymes.

M, K M, Dey T, Zargar MI, Singh J. Recent advance of herbal medicines in cancer- a molecular approach

Bioactive compounds are crucial for an extensive range of therapeutic uses, and some exhibit anticancer activity. Scientists advocate that phytochemicals modulate autophagy and apoptosis, involved in the underlying pathobiology of cancer development and regulation. The pharmacological aiming of the autophagy-apoptosis signaling pathway using phytocompounds hence offers an auspicious method that is complementary to conventional cancer chemotherapy. The current review aims to explore the molecular level of the autophagic-apoptotic pathway to know its implication in the pathobiology of cancer and explore the essential cellular process as a druggable anticancer target and therapeutic emergence of naturally derived phytocompound-based anticancer agents. The data in the review were collected from scientific databases such as Google search, Web of Science, PubMed, Scopus, Medline, and Clinical Trials. With a broad outlook, we investigated their cutting-edge scientifically revealed and/or searched pharmacologic effects, a novel mechanism of action, and molecular signaling pathway of phytochemicals in cancer therapy. In this review, the evidence is focused on molecular pharmacology, specifically caspase, Nrf2, NF-kB, autophagic-apoptotic pathway, and several mechanisms to understand their role in cancer biology.

Phytochemicals from Polyalthia Species: Potential and Implication on Anti-Oxidant, Anti-Inflammatory, Anti-Cancer, and Chemoprevention Activities

Polyalthia belong to the Annonaceae family and are a type of evergreen tree distributed across many tropical and subtropical regions. Polyalthia species have been used long term as indigenous medicine to treat certain diseases, including fever, diabetes, infection, digestive disease, etc. Recent studies have demonstrated that not only crude extracts but also the isolated pure compounds exhibit various pharmacological activities, such as anti-oxidant, anti-microbial, anti-tumor, anti-cancer, etc. It is known that the initiation of cancer usually takes several years and is related to unhealthy lifestyle, as well as dietary and environmental factors, such as stress, toxins and smoking. In fact, natural or synthetic substances have been used as cancer chemoprevention to delay, impede, or even stop cancer growing. This review is an attempt to collect current available phytochemicals from Polyalthia species, which exhibit anti-cancer potentials for chemoprevention purposes, providing directions for further research on the interesting agents and possible clinical applications.

3,4- seco-Norclerodane Diterpenoids from the Roots of Polyalthia laui

Ten new clerodane diterpenoids, polylauioids A-J (1-10), and five known analogues (11-15) were isolated from the roots of Polyalthia laui. Among the new compounds, 3 and 8 are artifacts. The structures were elucidated using spectroscopic methods and by comparison with published NMR spectroscopic data. The absolute configurations of 4, 5, and 7 were defined based on single-crystal X-ray diffraction and electronic circular dichroism data. Compounds 1 and 2 represent the first examples of rearranged 3,4- seco-norclerodane diterpenoids, and a putative biosynthesis pathway for these compounds is proposed. Compounds 1, 4, 6, 7, 9, and 10 showed anti-HIV activities with EC₅₀ values ranging from 12.2 to 35.2 μM.