Bioassay-Guided Isolation and Identification of Cytotoxic Compounds from Fruits.

The fruit extract of yielded a total of 19 compounds, including two novel spiro-biflavonoid enantiomers ( and ) and a chalcone derivative (). Their structures were determined through spectroscopic analysis. The enantiomers of the racemic mixture of compound were successfully resolved into (+)- and (-)- using chiral-phase HPLC.

Discovery of lead natural products for developing pan-SARS-CoV-2 therapeutics.

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global public health crisis. The reduced efficacy of therapeutic monoclonal antibodies against emerging SARS-CoV-2 variants of concern (VOCs), such as omicron BA.5 subvariants, has underlined the need to explore a novel spectrum of antivirals that are effective against existing and evolving SARS-CoV-2 VOCs.

Bioactive xanthones, benzophenones and biphenyls from mangosteen root with potential anti-migration against hepatocellular carcinoma cells.

Liver cancer refers primarily to hepatocellular carcinoma (HCC) accounting for over 90% of cases and is the highest incidence in men in Thailand. Over the past decades, the incidence of HCC dramatically increased with a strong rise of mortality rates. Garcinia mangostana, "Queen of Fruit" of Thailand, is known as a rich source of xanthones with potent cytotoxic properties against various cancer cells.

Cassane-type diterpenes from roots of Pterolobium macropterum and their anti-inflammatory activity.

Eight undescribed cassane diterpenes, pterolobirins C-J, together with two known analogs, were isolated from the roots of Pterolobium macropterum. Their structures were characterized by extensive spectroscopic techniques including NMR, MS, ECD and X-ray crystallographic spectroscopy. The absolute configuration of pterolobirin J was confirmed by single-crystal X-ray diffraction data.

Picrotoxane sesquiterpene and α-pyrone derivative from Dendrobium signatum and their free radical scavenging potency.

One new picrotoxane sesquiterpene (1) and one new α-pyrone derivative (4), together with nine known compounds, were isolated from the aerial parts of Dendrobium signatum. The structures of the new compounds were elucidated based on the interpretation of 1D and 2D NMR, HRESIMS and electronic circular dichroism (ECD) data. The absolute configuration of 1 was confirmed by single-crystal X-ray diffraction data.

Cytotoxicity and Nitric Oxide Production Inhibitory Activities of Compounds Isolated from the Plant Pathogenic Fungus sp.

Chemical investigation of the mycelia of the pathogenic fungus sp. which was isolated from a leaf of (crowfoot grass), resulted in the isolation of a new compound, curvulariahawadride (5), along with five known compounds (1-4, and 6). Their structures were determined on the basis of spectroscopic data, including 1D and 2D NMR and HRESIMS.

Two new xanthones from the root of Thai Calophyllum inophyllum and their toxicity against colon and liver cancer cells.

Two new xanthones, 1,3,6,7-tetrahydroxy-5-methoxy-4-(1',1'-dimethyl-2'-propenyl)-8-(3″,3″-dimethyl-2″-propenyl)-xanthone (1) and (2'S)-7-hydroxy caloxanthone B (2), were isolated from the root of Thai Calophyllum inophyllum Linn., together with twelve known xanthones (3-14). The structures of new compounds were elucidated based on spectroscopic data.

Pterolobirins A and B, Oxygen-Bridged Cassane Diterpenoid Dimers from the Fruits of .

Two dimeric cassane diterpenoids with an unprecedented 6/6/6/6/6/5/6/6/6 nonacyclic framework, pterolobirins A and B ( and ), were isolated from the fruits of . Their structures were assigned by interpreting the spectroscopic data. The absolute configuration of was unequivocally confirmed by single-crystal X-ray diffraction data.

Bioassay-guided isolation and identification of antidiabetic compounds from leaf extract.

Roxb. ex Choisy (Clusiaceae) is a Thai local edible plant, which has been used for the treatment of diabetes. The aim of this study is to discover and identify bioactive compounds related to antidiabetic properties from the leaf extract of .

Phloroglucinol Benzophenones and Xanthones from the Leaves of and Their Nitric Oxide Production and α-Glucosidase Inhibitory Activities.

Five new compounds-two phloroglucinol benzophenones, garciniacowones F () and G (), and three xanthones, garciniacowones H (), I (), and J ()-together with seven known xanthones (-) were isolated from the fresh leaves of . Their structures were elucidated by detailed analysis of NMR and MS data. Compounds and are phloroglucinol benzophenones containing a polyprenylated bicyclo[3.

Antibacterial and Inhibitory Activities against Nitric Oxide Production of Coumaronochromones and Prenylated Isoflavones from .

A chemical investigation of leaf and root extracts of led to the isolation and structural elucidation of four new prenylated isoflavones, millexatins G-J (-), and three new coumaronochromones, millexatins K-M (-), along with 16 known compounds. The structures of the new compounds were determined on the basis of NMR and MS data. Compound is a rare isoflavone having a 2-hydroxyethyl moiety at C-8, whereas the structures of compounds - formally arise from a ring closure through HO-2' and C-2.

A tocotrienol quinone dimer and xanthones from the leaf extract of Garcinia nigrolineata.

Four new compounds (1-4) together with six known compounds (5-10) were isolated from the leaf extract of Garcinia nigrolineata. Compound 4 is a rare tocotrienol quinone dimer. The structures were elucidated based on NMR and MS data.

Antibacterial Prenylated Isoflavonoids from the Stems of Millettia extensa.

The first phytochemical investigation of the stem extract of Millettia extensa resulted in the isolation and identification of six new isoflavones, millexatins A-F (1-6), together with 16 known compounds. The structures of these new compounds were determined on the basis of their spectroscopic data. Millexatin A (1) is a rare isoflavone containing three isoprenyl units on a modified A ring.

New Benzophenones and Xanthones from Cratoxylum sumatranum ssp. neriifolium and Their Antibacterial and Antioxidant Activities.

Two new benzophenones (1 and 2) and four new xanthones (4-6 and 17) together with 24 known compounds (3, 7-16, and 18-30) were isolated from the roots and twigs of Cratoxylum sumatranum ssp. neriifolium. Their structures were elucidated by spectroscopic methods.

Bioactive Xanthones from Cratoxylum cochinchinense.

Chemical investigation of Cratoxylum cochinchinense stem bark has led to the isolation and identification of a new xanthone, cochinchinone M (1), together with 12 known compounds. Their structures were elucidated on the basis of spectroscopic methods, including UV, IR, NMR and MS. Some compounds were evaluated for their antibacterial and acetylcholinesterase inhibitory activities.

Antibacterial compounds from the roots of Cratoxylumformosum spp. pruniflorum.

Phytochemical investigation of the roots of Cratoxylum formosum spp. pruniflolnnm led to the isolation and identification of a new xanthone, namely cratopruniforone (1), together with 13 known compounds (2-14). Some of these more abundant compounds were evaluated for their antibacterial activities.

Monoterpene indole alkaloids from the twigs of Kopsia arborea.

The phytochemistry of Kopsia arborea Blume has received considerable attention, which has resulted in the isolation of a number of new unusual indole alkaloids with intriguing structures. In this study, a new eburnane-type alkaloid, phutdonginin (1), together with eight known alkaloids: 19-OH-(-)- eburnamonine (2), melodinine E (3), kopsinine (4), kopsilongine (5), kopsamine (6), (-)-methylenedioxy-1 1,12-kopsinaline (7), decarbomethoxykopsiline (8), and vincadifformine (9), were isolated from the twigs of K. arborea.