## 2 Results and Discussion
The remaining five olefinic carbons (\(\delta_{\rm C}\) 107.1, 120.4, 149.5, 166.2, and 167.1) constructed an \(\alpha\)-pyrone moiety with a hydroxy at C-4 position, according to the HMBC cross-peaks from H-6 (\(\delta_{\rm H}\) 7.59) to C-2 (\(\delta_{\rm C}\) 166.2), C-4 (\(\delta_{\rm C}\) 167.2), C-5 (\(\delta_{\rm C}\) 120.4), and C-6', as well as their chemical shifts and the molecular formula. Therefore, the structure of **3** was elucidated to be 4-hydroxy-5-(4-hydroxyphenyl)-3-(4-methoxyphenyl)-2\(H\)-pyran-2-one, which was named asperpenlypyrone. It is of note that **3** was the first example of the \(\alpha\)-pyrone derivatives bearing two phenyl units at C-3 and C-5, respectively. Figure 4: Experimental (Exp.) and calculated (Cal.) ECD spectra of **2** in methanol at the B3 LYP/6-311+ G(2d,p) level. Figure 5: Selected COSY and HMBC correlations of compounds **3** and **4**. Compound **4** has the molecular formula of C\({}_{11}\)H\({}_{8}\)O\({}_{5}\) as determined by the positive HRESIMS spectrum (\(m\)/\(z\) 243.0268, [M + Na]\({}^{+}\)) and the \({}^{13}\)C NMR data, indicating eight degrees of unsaturation. The \({}^{1}\)H NMR spectrum showed three aromatic protons (\(\delta_{\rm H}\) 7.45 (d, \(J\) = 8.6 Hz, H-8), 7.95 (dd, \(J\) = 8.6, 1.8 Hz, H-7), and 8.23 (d, \(J\) = 1.8 Hz, H-5)) for a 1,2,4-trisubstituted benzene ring, a singlet olefinic proton (\(\delta_{\rm H}\) 7.49), and one methoxy (\(\delta_{\rm H}\) 3.86), whereas the \({}^{13}\)C NMR spectrum exhibited 11 carbon signals, including six aromatic carbons (\(\delta_{\rm C}\) 116.5, 120.4, 127.8, 128.9, 129.5, and 152.2) for a benzene ring, two olefinic carbons (\(\delta_{\rm C}\) 113.4, 144.8) for a double bond, two ester carbonyl carbons (156.6, 166.9), and a methoxy group (\(\delta_{\rm C}\) 56.8). The aforementioned NMR data were very similar to those of the known coumarin derivative [41], with the exception of the presence of an additional aromatic methine (\(\delta_{\rm H}\) 7.95, \(\delta_{\rm C}\) 129.5) in **4** instead of an oxygenated nonprotonated sp\({}^{2}\) carbon. The additional olefinic proton was appointed at C-7 (\(\delta_{\rm C}\) 129.5) on the basis of the COSY cross-peaks from H-7 (\(\delta_{\rm H}\) 7.95) to H-8 (\(\delta_{\rm H}\) 7.45) and H-5 (\(\delta_{\rm H}\) 8.23) as well as the HMBC correlations from H-5 to C-4 (\(\delta_{\rm C}\) 113.4)/C-7/C-9 (\(\delta_{\rm C}\) 166.9)/C-8a (\(\delta_{\rm C}\) 152.2) and from H-7 to C-5 (\(\delta_{\rm C}\) 128.9), C-9, and C-8a (Figure 5). Thus, the structure of **4** was established as a 7-deoxylated derivative of the above known compound, which was given the trivial name of aspercumarine acid. In addition, seven known compounds were established to be pestalotiolactone A (**5**) [42; 43], 3,7-dihydroxy-1,9-dimethyldibenzofuran (**6**) [44], diorcinol (**7**) [45], cordyol C (**8**) [46], 4-(3',_A_'-dihydroxyphenyl)-2-butanone (**9**) [47], 3,4,5-trimethoxybenzoic acid (**10**) [48], and 4-hydroxybenzoic acid (**11**) [49] on the basis of comparison of their NMR and specific rotation data with those reported in the literature. Compound **1** was a novel chained monoterenoid. The plausible biosynthetic pathway for **1** and **2** was proposed (Scheme 1). Starting from the GPP, hydrolysis, oxygenation, and cyclization reaction occurrence constructed the monocyclic ring monoterenoid osmane. The osmane might undergo carbon-carbon bond cleavage to form a key intermediate **A**, which was further oxygenated to yield **1**. Additionally, the osmane might also undergo oxygenation to form **2**. As terpenoids usually possess the anti-inflammatory activities, all isolated metabolites were evaluated for their inhibitory effects against NO secretion in LPS-activated BV-2 microglia cells.