Chemical constituents and bioactivity of Malaysian and Indonesian kaempferia rotunda

The essential oils and the phytochemicals of the rhizomes of Kaempferia rotunda cultivated in Malaysia and Indonesia have been studied. Hydrodistillation of the fresh rhizomes of K. rotunda gave 0.09% and 0.23% oils respectively. These oils were analyzed by GC (Kovats Indices) and GC-MS. The main constituents found in the rhizome oil of Malaysia were bornyl acetate (9.6%), benzyl benzoate (8.4%) and camphor (5.6%), while the rhizome oil from Indonesia was rich in benzyl benzoate (87.7%) and n-pentadecane (4.2%). Extractions by soxhlet apparatus were carried out on the dried samples to get the crude extracts. Fractionation and purification on the crude extracts resulted in the isolation of three new cyclohexane oxides and ten known compounds, comprising of cyclohexane oxides, esters, carboxylic acid, labdane diterpene, and flavonoids. Two new compounds identified as 2- (benzoyloxymethyl)phenyl (3-O-acetyl)-ß-glucopyranoside and 3-debenzoylrotepoxide A, together with seven known compounds, crotepoxide, 4- benzoyloxymethyl-3,8-dioxatricyclo[5.1.0.02,4]octane-5,6-diol 5-acetate, 1,6- desoxypipoxide, curcumrinol C, 2'-hydroxy-4,4',6'-trimethoxychalcone and naringenin 4',7-dimethyl ether were isolated from the Malaysian species, while a new compound identified as 3-acetoxy-2-benzoyloxy-1-(benzoyloxymethyl)-cyclohexa- 4,6-diene with the seven known compounds namely crotepoxide, 4- benzoyloxymethyl-3,8-dioxatricyclo[5.1.0.02,4]octane-5,6-diol 5-acetate, 1,6- desoxypipoxide, 6-acetylzeylenol, trans-docosyl ferulate, benzyl benzoate and benzoic acid were isolated from the Indonesian species. The structures of all compounds were established based on spectral studies using MS, IR, UV and NMR spectroscopies. Naringenin 4',7-dimethyl ether, curcumrinol C, trans-docosyl ferulate, and benzoic acid were found for the first time from K. rotunda and also the genus of Kaempferia. Antibacterial and antioxidant screening assays using discdiffusion method and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) method, respectively were carried out on the crude extracts and essential oils. The crude extracts and essential oils of K. rotunda from Malaysia and Indonesia did not show activities on antibacterial and antioxidant assay

[1R-(1α,2α,4α,5β,6α,7α)]-4-Benzoyl­oxymethyl-5,6-dihy­droxy-3,8-dioxa­tricyclo­[5.1.0.02,4]octan-5-yl acetate (3-deacetyl­crotepoxide) from Kaempferia rotunda Val.

The title compound, C16H16O7, isolated from Kaempferia rotunda rhizomes, features a six-membered cyclo­hexane ring that adopts a twisted-boat conformation owing to the presence of two adjacent epoxide attachments that lock in four of the six axial positions. The CH3CO2– and HO– substituents occupy equatorial positions. However, the bond angles at the ring carbon connected to the C6H5CO2CH2– substituent deviate signifcantly from the idealized tetra­hedral angles as the carbon atom is part of an epoxide ring. In the crystal, the molecules are linked into chains by O—H⋯O hydrogen bonds

(E)-1-(2-Hy­droxy-4,6-dimeth­oxy­phen­yl)-3-(4-meth­oxy­phen­yl)prop-2-en-1-one from Kaempferia rotunda Val.

The planar –CH=CHC(=O)– fragment (r.m.s. deviation = 0.074 Å) in the title compound, C18H18O5, connects the planar hy­droxy­dimeth­oxy­phenyl (r.m.s. deviation = 0.039 Å) and meth­oxy­lphenyl (r.m.s. deviation = 0.021 Å) parts. The central fragment forms a dihedral angle of 13.7 (1)° with the hy­droxy­dimeth­oxy­phenyl part and 32.0 (1)° with the meth­oxy­phenyl part. The hy­droxy group forms an intra­molecular hydrogen bond to the carbonyl O atom

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field